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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/.cvsignore | 12 | ||||
| -rw-r--r-- | doc/Makefile.am | 28 | ||||
| -rw-r--r-- | doc/gpl.texi | 400 | ||||
| -rw-r--r-- | doc/mdk.texi | 213 | ||||
| -rw-r--r-- | doc/mdk_bugs.texi | 16 | ||||
| -rw-r--r-- | doc/mdk_emixvm.texi | 25 | ||||
| -rw-r--r-- | doc/mdk_gmixvm.texi | 118 | ||||
| -rw-r--r-- | doc/mdk_gstart.texi | 433 | ||||
| -rw-r--r-- | doc/mdk_index.texi | 10 | ||||
| -rw-r--r-- | doc/mdk_install.texi | 180 | ||||
| -rw-r--r-- | doc/mdk_intro.texi | 48 | ||||
| -rw-r--r-- | doc/mdk_mixasm.texi | 79 | ||||
| -rw-r--r-- | doc/mdk_mixvm.texi | 478 | ||||
| -rw-r--r-- | doc/mdk_tut.texi | 1259 | ||||
| -rw-r--r-- | doc/ss_devices.png | bin | 0 -> 16621 bytes | |||
| -rw-r--r-- | doc/ss_mix.png | bin | 0 -> 12642 bytes | |||
| -rw-r--r-- | doc/ss_mix.txt | 31 | ||||
| -rw-r--r-- | doc/ss_mixal.png | bin | 0 -> 14536 bytes | |||
| -rw-r--r-- | doc/ss_worddlg.png | bin | 0 -> 15050 bytes |
19 files changed, 3330 insertions, 0 deletions
diff --git a/doc/.cvsignore b/doc/.cvsignore new file mode 100644 index 0000000..cad9468 --- /dev/null +++ b/doc/.cvsignore @@ -0,0 +1,12 @@ +Makefile +Makefile.in +mdk-0.1 +mdk-doc-html-0.2.tar.gz +mdk-doc.tar.gz +mdk.html +mdk.info +mdk.info-1 +mdk.info-2 +mdk.info-3 +stamp-vti +version.texi diff --git a/doc/Makefile.am b/doc/Makefile.am new file mode 100644 index 0000000..42953a8 --- /dev/null +++ b/doc/Makefile.am @@ -0,0 +1,28 @@ +## Process this file with automake to produce Makefile.in + +# Copyright (C) 2000 Free Software Foundation, Inc. +# +# This file is free software; as a special exception the author gives +# unlimited permission to copy and/or distribute it, with or without +# modifications, as long as this notice is preserved. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY, to the extent permitted by law; without even the +# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + +SUBDIRS = html +SUFFIXES = .html + + +info_TEXINFOS = mdk.texi +mdk_TEXINFOS = gpl.texi mdk_intro.texi mdk_tut.texi mdk_gstart.texi \ + mdk_mixvm.texi mdk_emixvm.texi mdk_mixasm.texi mdk_bugs.texi \ + mdk_index.texi + +html_docs = mdk.html + +.texi.html: + $(MAKEINFO) --html $< + +.PHONY: html +html: version.texi gpl.texi $(html_docs)
\ No newline at end of file diff --git a/doc/gpl.texi b/doc/gpl.texi new file mode 100644 index 0000000..361504a --- /dev/null +++ b/doc/gpl.texi @@ -0,0 +1,400 @@ +@node Copying, Problems, mixasm, Top +@chapter Copying +@lowersections + +@unnumbered GNU GENERAL PUBLIC LICENSE +@center Version 2, June 1991 + +@display +Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc. +675 Mass Ave, Cambridge, MA 02139, USA + +Everyone is permitted to copy and distribute verbatim copies +of this license document, but changing it is not allowed. +@end display + +@unnumberedsec Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. By contrast, the GNU General Public +License is intended to guarantee your freedom to share and change free +software---to make sure the software is free for all its users. This +General Public License applies to most of the Free Software +Foundation's software and to any other program whose authors commit to +using it. (Some other Free Software Foundation software is covered by +the GNU Library General Public License instead.) You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. Our General Public Licenses are designed to make sure that you +have the freedom to distribute copies of free software (and charge for +this service if you wish), that you receive source code or can get it +if you want it, that you can change the software or use pieces of it +in new free programs; and that you know you can do these things. + + To protect your rights, we need to make restrictions that forbid +anyone to deny you these rights or to ask you to surrender the rights. +These restrictions translate to certain responsibilities for you if you +distribute copies of the software, or if you modify it. + + For example, if you distribute copies of such a program, whether +gratis or for a fee, you must give the recipients all the rights that +you have. You must make sure that they, too, receive or can get the +source code. And you must show them these terms so they know their +rights. + + We protect your rights with two steps: (1) copyright the software, and +(2) offer you this license which gives you legal permission to copy, +distribute and/or modify the software. + + Also, for each author's protection and ours, we want to make certain +that everyone understands that there is no warranty for this free +software. If the software is modified by someone else and passed on, we +want its recipients to know that what they have is not the original, so +that any problems introduced by others will not reflect on the original +authors' reputations. + + Finally, any free program is threatened constantly by software +patents. We wish to avoid the danger that redistributors of a free +program will individually obtain patent licenses, in effect making the +program proprietary. To prevent this, we have made it clear that any +patent must be licensed for everyone's free use or not licensed at all. + + The precise terms and conditions for copying, distribution and +modification follow. + +@iftex +@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION +@end iftex +@ifinfo +@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION +@end ifinfo + +@enumerate +@item +This License applies to any program or other work which contains +a notice placed by the copyright holder saying it may be distributed +under the terms of this General Public License. The ``Program'', below, +refers to any such program or work, and a ``work based on the Program'' +means either the Program or any derivative work under copyright law: +that is to say, a work containing the Program or a portion of it, +either verbatim or with modifications and/or translated into another +language. (Hereinafter, translation is included without limitation in +the term ``modification''.) Each licensee is addressed as ``you''. + +Activities other than copying, distribution and modification are not +covered by this License; they are outside its scope. The act of +running the Program is not restricted, and the output from the Program +is covered only if its contents constitute a work based on the +Program (independent of having been made by running the Program). +Whether that is true depends on what the Program does. + +@item +You may copy and distribute verbatim copies of the Program's +source code as you receive it, in any medium, provided that you +conspicuously and appropriately publish on each copy an appropriate +copyright notice and disclaimer of warranty; keep intact all the +notices that refer to this License and to the absence of any warranty; +and give any other recipients of the Program a copy of this License +along with the Program. + +You may charge a fee for the physical act of transferring a copy, and +you may at your option offer warranty protection in exchange for a fee. + +@item +You may modify your copy or copies of the Program or any portion +of it, thus forming a work based on the Program, and copy and +distribute such modifications or work under the terms of Section 1 +above, provided that you also meet all of these conditions: + +@enumerate a +@item +You must cause the modified files to carry prominent notices +stating that you changed the files and the date of any change. + +@item +You must cause any work that you distribute or publish, that in +whole or in part contains or is derived from the Program or any +part thereof, to be licensed as a whole at no charge to all third +parties under the terms of this License. + +@item +If the modified program normally reads commands interactively +when run, you must cause it, when started running for such +interactive use in the most ordinary way, to print or display an +announcement including an appropriate copyright notice and a +notice that there is no warranty (or else, saying that you provide +a warranty) and that users may redistribute the program under +these conditions, and telling the user how to view a copy of this +License. (Exception: if the Program itself is interactive but +does not normally print such an announcement, your work based on +the Program is not required to print an announcement.) +@end enumerate + +These requirements apply to the modified work as a whole. If +identifiable sections of that work are not derived from the Program, +and can be reasonably considered independent and separate works in +themselves, then this License, and its terms, do not apply to those +sections when you distribute them as separate works. But when you +distribute the same sections as part of a whole which is a work based +on the Program, the distribution of the whole must be on the terms of +this License, whose permissions for other licensees extend to the +entire whole, and thus to each and every part regardless of who wrote it. + +Thus, it is not the intent of this section to claim rights or contest +your rights to work written entirely by you; rather, the intent is to +exercise the right to control the distribution of derivative or +collective works based on the Program. + +In addition, mere aggregation of another work not based on the Program +with the Program (or with a work based on the Program) on a volume of +a storage or distribution medium does not bring the other work under +the scope of this License. + +@item +You may copy and distribute the Program (or a work based on it, +under Section 2) in object code or executable form under the terms of +Sections 1 and 2 above provided that you also do one of the following: + +@enumerate a +@item +Accompany it with the complete corresponding machine-readable +source code, which must be distributed under the terms of Sections +1 and 2 above on a medium customarily used for software interchange; or, + +@item +Accompany it with a written offer, valid for at least three +years, to give any third party, for a charge no more than your +cost of physically performing source distribution, a complete +machine-readable copy of the corresponding source code, to be +distributed under the terms of Sections 1 and 2 above on a medium +customarily used for software interchange; or, + +@item +Accompany it with the information you received as to the offer +to distribute corresponding source code. (This alternative is +allowed only for noncommercial distribution and only if you +received the program in object code or executable form with such +an offer, in accord with Subsection b above.) +@end enumerate + +The source code for a work means the preferred form of the work for +making modifications to it. For an executable work, complete source +code means all the source code for all modules it contains, plus any +associated interface definition files, plus the scripts used to +control compilation and installation of the executable. However, as a +special exception, the source code distributed need not include +anything that is normally distributed (in either source or binary +form) with the major components (compiler, kernel, and so on) of the +operating system on which the executable runs, unless that component +itself accompanies the executable. + +If distribution of executable or object code is made by offering +access to copy from a designated place, then offering equivalent +access to copy the source code from the same place counts as +distribution of the source code, even though third parties are not +compelled to copy the source along with the object code. + +@item +You may not copy, modify, sublicense, or distribute the Program +except as expressly provided under this License. Any attempt +otherwise to copy, modify, sublicense or distribute the Program is +void, and will automatically terminate your rights under this License. +However, parties who have received copies, or rights, from you under +this License will not have their licenses terminated so long as such +parties remain in full compliance. + +@item +You are not required to accept this License, since you have not +signed it. However, nothing else grants you permission to modify or +distribute the Program or its derivative works. These actions are +prohibited by law if you do not accept this License. Therefore, by +modifying or distributing the Program (or any work based on the +Program), you indicate your acceptance of this License to do so, and +all its terms and conditions for copying, distributing or modifying +the Program or works based on it. + +@item +Each time you redistribute the Program (or any work based on the +Program), the recipient automatically receives a license from the +original licensor to copy, distribute or modify the Program subject to +these terms and conditions. You may not impose any further +restrictions on the recipients' exercise of the rights granted herein. +You are not responsible for enforcing compliance by third parties to +this License. + +@item +If, as a consequence of a court judgment or allegation of patent +infringement or for any other reason (not limited to patent issues), +conditions are imposed on you (whether by court order, agreement or +otherwise) that contradict the conditions of this License, they do not +excuse you from the conditions of this License. If you cannot +distribute so as to satisfy simultaneously your obligations under this +License and any other pertinent obligations, then as a consequence you +may not distribute the Program at all. For example, if a patent +license would not permit royalty-free redistribution of the Program by +all those who receive copies directly or indirectly through you, then +the only way you could satisfy both it and this License would be to +refrain entirely from distribution of the Program. + +If any portion of this section is held invalid or unenforceable under +any particular circumstance, the balance of the section is intended to +apply and the section as a whole is intended to apply in other +circumstances. + +It is not the purpose of this section to induce you to infringe any +patents or other property right claims or to contest validity of any +such claims; this section has the sole purpose of protecting the +integrity of the free software distribution system, which is +implemented by public license practices. Many people have made +generous contributions to the wide range of software distributed +through that system in reliance on consistent application of that +system; it is up to the author/donor to decide if he or she is willing +to distribute software through any other system and a licensee cannot +impose that choice. + +This section is intended to make thoroughly clear what is believed to +be a consequence of the rest of this License. + +@item +If the distribution and/or use of the Program is restricted in +certain countries either by patents or by copyrighted interfaces, the +original copyright holder who places the Program under this License +may add an explicit geographical distribution limitation excluding +those countries, so that distribution is permitted only in or among +countries not thus excluded. In such case, this License incorporates +the limitation as if written in the body of this License. + +@item +The Free Software Foundation may publish revised and/or new versions +of the General Public License from time to time. Such new versions will +be similar in spirit to the present version, but may differ in detail to +address new problems or concerns. + +Each version is given a distinguishing version number. If the Program +specifies a version number of this License which applies to it and ``any +later version'', you have the option of following the terms and conditions +either of that version or of any later version published by the Free +Software Foundation. If the Program does not specify a version number of +this License, you may choose any version ever published by the Free Software +Foundation. + +@item +If you wish to incorporate parts of the Program into other free +programs whose distribution conditions are different, write to the author +to ask for permission. For software which is copyrighted by the Free +Software Foundation, write to the Free Software Foundation; we sometimes +make exceptions for this. Our decision will be guided by the two goals +of preserving the free status of all derivatives of our free software and +of promoting the sharing and reuse of software generally. + +@iftex +@heading NO WARRANTY +@end iftex +@ifinfo +@center NO WARRANTY +@end ifinfo + +@item +BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY +FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN +OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES +PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED +OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS +TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE +PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, +REPAIR OR CORRECTION. + +@item +IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. +@end enumerate + +@iftex +@heading END OF TERMS AND CONDITIONS +@end iftex +@ifinfo +@center END OF TERMS AND CONDITIONS +@end ifinfo + +@page +@unnumberedsec How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the ``copyright'' line and a pointer to where the full notice is found. + +@smallexample +@var{one line to give the program's name and an idea of what it does.} +Copyright (C) 19@var{yy} @var{name of author} + +This program is free software; you can redistribute it and/or +modify it under the terms of the GNU General Public License +as published by the Free Software Foundation; either version 2 +of the License, or (at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +@end smallexample + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + +@smallexample +Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author} +Gnomovision comes with ABSOLUTELY NO WARRANTY; for details +type `show w'. This is free software, and you are welcome +to redistribute it under certain conditions; type `show c' +for details. +@end smallexample + +The hypothetical commands @samp{show w} and @samp{show c} should show +the appropriate parts of the General Public License. Of course, the +commands you use may be called something other than @samp{show w} and +@samp{show c}; they could even be mouse-clicks or menu items---whatever +suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a ``copyright disclaimer'' for the program, if +necessary. Here is a sample; alter the names: + +@smallexample +@group +Yoyodyne, Inc., hereby disclaims all copyright +interest in the program `Gnomovision' +(which makes passes at compilers) written +by James Hacker. + +@var{signature of Ty Coon}, 1 April 1989 +Ty Coon, President of Vice +@end group +@end smallexample + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Library General +Public License instead of this License. + +@raisesections diff --git a/doc/mdk.texi b/doc/mdk.texi new file mode 100644 index 0000000..ba5b94f --- /dev/null +++ b/doc/mdk.texi @@ -0,0 +1,213 @@ +\input texinfo +@c %**start of header +@setfilename mdk.info +@settitle GNU MIX Development Kit (mdk) +@finalout +@setchapternewpage odd +@c %**end of header + +@set UPDATED 20 February 2001 +@set EDITION 0.3 +@set VERSION 0.3 +@set JAO Jos@'e Antonio Ortega Ruiz +@set PHILIP Philip E. King +@footnotestyle separate + +@ifinfo +This file documents the the GNU @sc{mdk} utilities for developing +programs using Donald Knuth's MIX language. + +Copyright (C) 2000, 2001 Free Software Foundation, Inc. + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +are preserved on all copies. + +@ignore +Permission is granted to process this file through TeX and print the +results, provided the printed document carries copying permission +notice identical to this one except for the removal of this paragraph +(this paragraph not being relevant to the printed manual). + +@end ignore +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, provided also that the +sections entitled ``Copying'' and ``GNU General Public License'' are +included exactly as in the original, and provided that the entire +resulting derived work is distributed under the terms of a permission +notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions, +except that this permission notice may be stated in a translation +approved by the Free Software Foundation. +@end ifinfo + +@titlepage +@title GNU MDK +@subtitle GNU MIX Development Kit +@subtitle Edition @value{EDITION}, for GNU @sc{mdk} Version @value{VERSION} +@subtitle @value{UPDATED} +@author by @value{JAO} + +@page +@vskip 0pt plus 1filll +Copyright @copyright{} 2000, 2001 Free Software Foundation, Inc. + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +are preserved on all copies. + +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, provided also that the +sections entitled ``Copying'' and ``GNU General Public License'' are +included exactly as in the original, and provided that the entire +resulting derived work is distributed under the terms of a permission +notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions, +except that this permission notice may be stated in a translation +approved by the Free Software Foundation. +@end titlepage + +@node Top, Introduction, (dir), (dir) + +@ifinfo +This file documents the GNU @sc{mdk} utilities to develop, run and debug +programs written in the MIXAL programming language. MIXAL is an +assembler-like language for programming a virtual computer called +MIX. They were created by Donald Knuth in the first volume of @cite{The +Art of Computer Programming} (Addison Wesley, 1997). + +GNU @sc{mdk} is an official GNU package. + +GNU @sc{mdk} was written by @value{JAO} and is released under the GNU +General Public license (@pxref{Copying}), so that users are free to share +and improve it. + +@value{PHILIP} has contributed to this package development with many +helpful discussions, as well as actual code (@pxref{mixvm.el}). + +@end ifinfo + +@menu +* Introduction:: +* Installing MDK:: +* MIX and MIXAL tutorial:: Learn the innards of MIX and MIXAL. +* Getting started:: Basic usage of the @sc{mdk} tools. +* mixvm.el:: Using @code{mixvm} within Emacs. +* mixvm:: Invoking and using the MIX virtual machine. +* gmixvm:: +* mixasm:: Invoking the MIXAL assembler. +* Copying:: @sc{mdk} licensing terms. +* Problems:: Reporting bugs. +* Concept Index:: Index of concepts. + + + + + + + + +@detailmenu + --- The Detailed Node Listing --- + +Installing @sc{mdk} + +* Download:: +* Requirements:: +* Basic installation:: +* Emacs support:: +* Special configure flags:: + +MIX and MIXAL tutorial + +* The MIX computer:: Architecture and instruction set + of the MIX computer. +* MIXAL:: The MIX assembly language. + +The MIX computer + +* MIX architecture:: +* MIX instruction set:: + +MIX instruction set + +* Instruction structure:: +* Loading operators:: +* Storing operators:: +* Arithmetic operators:: +* Address transfer operators:: +* Comparison operators:: +* Jump operators:: +* Input-output operators:: +* Conversion operators:: +* Shift operators:: +* Miscellaneous operators:: +* Execution times:: + +MIXAL + +* Basic structure:: Writing basic MIXAL programs. +* MIXAL directives:: Assembler directives. +* Expressions:: Evaluation of expressions. +* W-expressions:: Evaluation of w-expressions. +* Local symbols:: Special symbol table entries. +* Literal constants:: Specifying an immediate operand. + +Getting started + +* Writing a source file:: A sample MIXAL source file. +* Compiling:: Using @code{mixasm} to compile source + files into binary format. +* Running the program:: Running and debugging your program. + +Running the program + +* Non-interactive mode:: Running your programs non-interactively. +* Interactive mode:: Running programs interactively. +* Debugging:: Commands for debugging your programs. + +@code{mixvm}, the MIX computer simulator + +* Invocation:: Options when invoking @code{mixvm}. +* Commands:: Commands available in interactive mode. +* Devices:: MIX block devices implementation. + +Interactive commands + +* File commands:: Loading and executing programs. +* Debug commands:: Debugging programs. +* State commands:: Inspecting the virtual machine state. + +gmixvm + +* Invoking @code{gmixvm}:: +* MIX virtual machine:: +* Menu and status bars:: + +@code{mixasm}, the MIXAL assembler + +* Invoking @code{mixasm}:: @code{mixasm} options + +@end detailmenu +@end menu + +@include mdk_intro.texi +@include mdk_install.texi +@include mdk_tut.texi +@include mdk_gstart.texi +@include mdk_emixvm.texi +@include mdk_mixvm.texi +@include mdk_gmixvm.texi +@include mdk_mixasm.texi +@include gpl.texi +@include mdk_bugs.texi +@include mdk_index.texi + + +@shortcontents +@contents +@bye diff --git a/doc/mdk_bugs.texi b/doc/mdk_bugs.texi new file mode 100644 index 0000000..7531daa --- /dev/null +++ b/doc/mdk_bugs.texi @@ -0,0 +1,16 @@ +@node Problems, Concept Index, Copying, Top +@chapter Reporting Bugs +@cindex bugs +@cindex problems +@cindex questions +@cindex suggestions + +If you have any questions, comments or suggestions, please send +electronic mail to @email{jao@@gnu.org, the author}. + +If you find a bug in @sc{mdk}, please send electronic mail to +@email{bug-mdk@@gnu.org, the @sc{mdk} bug list}. + +In your report, please include the version number, which you can find by +running @w{@samp{mixasm --version}}. Also include in your message the +output that the program produced and the output you expected. diff --git a/doc/mdk_emixvm.texi b/doc/mdk_emixvm.texi new file mode 100644 index 0000000..8fcbf55 --- /dev/null +++ b/doc/mdk_emixvm.texi @@ -0,0 +1,25 @@ +@node mixvm.el, mixvm, Getting started, Top +@comment node-name, next, previous, up +@chapter mixvm.el + +If you are an Emacs user and write your MIXAL programs using this +editor, you will find the elisp program @file{mixvm.el} quite +useful@footnote{@file{mixvm.el} has been kindly contributed by +@value{PHILIP}. @file{mixvm.el} is based on a study of gdb, perldb, and +pdb as found in @file{gud.el}, and @file{rubydb3x.el} distributed with +the source code to the Ruby language.}. @file{mixvm.el} allows running +the MIX virtual machine @code{mixvm} (@pxref{mixvm}) inside an Emacs +@acronym{GUD} buffer, while visiting the MIXAL source file in another +buffer. + +After installing @file{mixvm.el} (@pxref{Emacs support}), you can +initiate an @sc{mdk}/@acronym{GUD} session inside Emacs with the command + +@example +M-x mixvm +@end example + +@noindent +and you will have a @code{mixvm} prompt inside a newly created +@acronym{GUD} buffer. @acronym{GUD} will reflect the current line in the +corresponding source file buffer. diff --git a/doc/mdk_gmixvm.texi b/doc/mdk_gmixvm.texi new file mode 100644 index 0000000..f3ed33b --- /dev/null +++ b/doc/mdk_gmixvm.texi @@ -0,0 +1,118 @@ +@node gmixvm, mixasm, mixvm, Top +@comment node-name, next, previous, up +@chapter gmixvm +@cindex @code{gmixvm} +@cindex GUI +@cindex GTK+ + +@menu +* Invoking @code{gmixvm}:: Invoking the GTK+ interface. +* MIX virtual machine:: The MIX virtual machine window. +* Menu and status bars:: Available menu commands. +@end menu + +@node Invoking @code{gmixvm}, MIX virtual machine, gmixvm, gmixvm +@comment node-name, next, previous, up +@section Invoking @code{gmixvm} + +If you have built @sc{mdk} with GTK+ support (@pxref{Installing MDK}), a +graphical front-end for the MIX virtual machine will be available in +your system. You can invoke it by typing + +@example +gmixvm @kbd{RET} +@end example + +@noindent +at your command prompt. The @code{gmixvm} main window will appear, +offering you a graphical interface to run and debug your MIX programs. + +@image{ss_mix} + +Apart from the menu and status bars, we can distinguish two zones (or +halves) in this main window. In the upper half of @code{gmixvm}'s main +window there is a notebook with three pages, namely, + +@itemize +@item +a MIX virtual machine view, which shows you the registers, flags, memory +contents and time statistics of the virtual machine; +@item +a MIXAL source view, which shows the MIXAL file and lets you manage +breakpoints; +@item +a Devices view, which shows you the output to character based MIX block +devices. +@end itemize + +@noindent +On the other hand, the main window's lower half presents you a +@code{mixvm} command prompt and a logging area where results of the +issued commands are presented. + +The following sections describe the above mentioned components of +@code{gmixvm}. + +@node MIX virtual machine, Menu and status bars, Invoking @code{gmixvm}, gmixvm +@comment node-name, next, previous, up +@section MIX virtual machine + +The first notebook's page displays the current status of the virtual +machine. There you can find the registers' contents, the value of the +comparison and overflow flags, the location pointer, a list with all MIX +memory cells and their contents, and the time statistics (including +total uptime, elapsed time since the last run command and total +execution time for the currently loaded MIX program). + +Clicking any register entry, you will be prompted for a new register's +contents +@ifnotinfo +(as shown in the next figure). +@image{ss_worddlg} +@end ifnotinfo + +In the same manner, click on any address of the memory cells list to be +prompted for the new contents of the clicked cell. If you click the +address column's title, a dialog asking you for a memory address will +appear; if you introduce a valid address, this will be the first cell +displayed in the scrollable list after you click the OK button. + + +@node Menu and status bars, , MIX virtual machine, gmixvm +@comment node-name, next, previous, up +@section Menu and status bars + +The menu bar gives you access to the following commands: + +@deffn File Load... +Opens a file dialog that lets you specify a binary MIX file to be loaded +in the virtual machine's memory. It is equivalent to the @code{mixvm}'s +@code{load} command (@pxref{File commands}). +@end deffn + +@deffn File Exit +Exits the application. +@end deffn + +@deffn Debug Run +Runs the currently loaded MIX program, up to the next breakpoint. It is +equivalent to the @code{mixvm}'s @code{run} command (@pxref{Debug +commands}). +@end deffn + +@deffn Debug Next +Executes the next MIX instruction. It is equivalent to the +@code{mixvm}'s @code{next} command (@pxref{Debug commands}). +@end deffn + +@deffn Debug Clear breakpoints +Clears all currently set breakpoints. It is equivalent to the +@code{mixvm}'s @code{cabp} command. +@end deffn + +@deffn Help About... +Shows information about @code{gmixvm}'s version and copyright. +@end deffn + +On the other hand, the status bar displays the name of the last loaded +MIX file. diff --git a/doc/mdk_gstart.texi b/doc/mdk_gstart.texi new file mode 100644 index 0000000..bde4160 --- /dev/null +++ b/doc/mdk_gstart.texi @@ -0,0 +1,433 @@ +@node Getting started, mixvm.el, MIX and MIXAL tutorial, Top +@comment node-name, next, previous, up +@chapter Getting started + +In this chapter, you will find a sample code-compile-run-debug session +using the @sc{mdk} utilities. Familiarity with the MIX mythical computer +and its assembly language MIXAL (as described in Knuth's TAOCP) is +assumed; for a compact reminder, see @ref{MIX and MIXAL tutorial}. + +@menu +* Writing a source file:: A sample MIXAL source file. +* Compiling:: Using @code{mixasm} to compile source + files into binary format. +* Running the program:: Running and debugging your program. +@end menu + +@node Writing a source file, Compiling, Getting started, Getting started +@comment node-name, next, previous, up +@section Writing a source file +@cindex MIXAL +@cindex source file + +MIXAL programs can be written as ASCII files with your editor of choice. +Here you have the mandatory @emph{hello world} as written in the MIXAL +assembly language: + +@example +* (1) +* hello.mixal: say 'hello world' in MIXAL (2) +* (3) +* label ins operand comment (4) +TERM EQU 19 the MIX console device number (5) + ORIG 1000 start address (6) +START OUT MSG(TERM) output data at address MSG (7) + HLT halt execution (8) +MSG ALF "MIXAL" (9) + ALF " HELL" (10) + ALF "O WOR" (11) + ALF "LD " (12) + END START end of the program (13) +@end example + +@noindent MIXAL source files should have the extension @file{.mixal} +when used with the @sc{mdk} utilities. As you can see in the above +sample, each line in a MIXAL file can be divided into four fields +separated by an arbitrary amount of whitespace characters (blanks and or +tabs). While Knuth's definition of MIXAL each field must start at a +fixed pre-defined column number, the @sc{mdk} assembler loosens this +requirement and lets you format the file as you see fit. The only +restrictions retained are for comment lines (like 1-4) which must begin +with an asterisk (*) placed at column 1, and for the label field (see +below) which, if present, must also start at column 1. The four fields +in each non-comment line are: + +@itemize @minus +@item +an optional label, which either refers to the current memory address (as +@code{START} and @code{MSG} in lines 7 and 9) or a defined symbol +(@code{TERM}) (if present, the label must always start at the first +column in its line, for the first whitespace in the line maks the +beginning of the second field), +@item +an operation mnemonic, which can represent either a MIX instruction +(@code{OUT} and @code{HLT} in lines 6 and 7 above), or an assembly +pseudoinstruction. +@item +an optional operand for the (pseudo)instruction, and +@item +an optional free text comment. +@end itemize + +@noindent Lines 9-12 of the @file{hello.mixal} file above also show the +second (and last) difference between Knuth's MIXAL definition and ours: +the operand of the @code{ALF} pseudoinstruction (a word of five +characters) must be quoted with using ""@footnote{In Knuth's definition, +the operand always starts at a fixed column number, and the use of +quotation is therefore unnecessary. As @code{mixasm} releases this +requirement, marking the beginning and end of the @code{ALF} operand +disambiguates the parser's recognition of this operand when it includes +blanks}. + +The workings of this sample program should be straightforward if you are +familiar with MIXAL. See TAOCP vol. 1 for a thorought definition or +@ref{MIX and MIXAL tutorial}, for a quick tutorial. + +@node Compiling, Running the program, Writing a source file, Getting started +@comment node-name, next, previous, up +@section Compiling +@cindex compiling +@cindex binary programs +@cindex virtual machine +@cindex assembler +@cindex @code{mixasm} + +A simulator of the MIX computer, called @code{mixvm} (MIX virtual +machine) is included in the @sc{mdk} tools. It is able to run binary +files containing MIX instructions written in their binary +representation. You can translate MIXAL source files into this binary +form using @code{mixasm}, the MIXAL assembler. So, in order to compile +the @file{hello.mixal} file, you can type the following +command at your shell prompt: + +@example +mixasm -g hello @key{RET} +@end example + +If the source file contains no errors, this will produce a binary file +called @file{hello.mix} which can be loaded and run by the MIX virtual +machine. The @code{-g} flag tells the assembler to include debug +information in the executable file (for a complete description of all +the compilation options, see @ref{mixasm}.) Now, your are ready to run +your first MIX program, as described in the following section. + + +@node Running the program, , Compiling, Getting started +@comment node-name, next, previous, up +@section Running the program +@cindex @code{mixvm} +@cindex non-interactive mode +@cindex interactive mode + +MIX is a mythical computer, so it is no use ordering it from your +favorite hardware provider. @sc{mdk} provides a software simulator of +the computer, though. It is called @code{mixvm}, which stands for +@dfn{MIX virtual machine}. Using it, you can run your MIXAL programs, +after compiling them with @code{mixasm} into binary @file{.mix} +files. @code{mixvm} can be used either in @dfn{interactive} or +@dfn{non-interactive} mode. In the second case, @code{mixvm} will load +your program into memory, execute it (producing any output due to MIXAL +@code{OUT} instructions present in the program), and exit when it +encounters a @code{HLT} instruction. In interactive mode, you will enter +a shell prompt which allows you issuing commands to the running virtual +machine. This commands will permit you loading, running and debugging +programs, as well as inspecting the MIX computer state (register +contents, memory cells contents and so on). + +@menu +* Non-interactive mode:: Running your programs non-interactively. +* Interactive mode:: Running programs interactively. +* Debugging:: Commands for debugging your programs. +@end menu + +@node Non-interactive mode, Interactive mode, Running the program, Running the program +@comment node-name, next, previous, up +@subsection Non-interactive mode +@cindex non-interactive mode + +To make @code{mixvm} work in non-interactive mode, use the @code{-r} +flag. Thus, to run our @file{hello.mix} program, simply type + +@example +mixvm -r hello @key{RET} +@end example + +@noindent at your command prompt, and you will get the following output: + +@example +MIXAL HELLO WORLD +** Execution time: 11 +@end example + +@noindent Since our hello world program uses MIX's device number 19 as +its output device (@pxref{Writing a source file}), the output is +redirected to the shell's standard output. Had you used any other MIX +output devices (disks, drums, line printer, etc.), @code{mixvm} would +have created a file named after the device used (e.g. @file{disk4.dev}) +and written its output there. Note also that the virtual machine reports +the execution time of the program, according to the (virtual) time spent +in each of the binary instructions (@pxref{Execution times}). + +Sometimes, you will prefer to store the results of your program in MIX +registers rather than writing them to a device. In such cases, +@code{mixvm}'s @code{-d} flag is your friend: it makes @code{mixvm} to +dump the contents of its registers and flags after executing the loaded +program. For instance, typing the following command at your shell's +prompt + +@example +mixvm -d -r hello +@end example + +@noindent you will obtain the following output: + +@example +MIXAL HELLO WORLD +** Execution time: 11 +rA: + 00 00 00 00 00 (0000000000) +rX: + 00 00 00 00 00 (0000000000) +rJ: + 00 00 (0000) +rI1: + 00 00 (0000) rI2: + 00 00 (0000) +rI3: + 00 00 (0000) rI4: + 00 00 (0000) +rI5: + 00 00 (0000) rI6: + 00 00 (0000) +Overflow: F +Cmp: E +@end example + +@noindent which, in addition to the program's outputs and execution +time, gives you the contents of the MIX registers and the values of the +overflow toggle and comparison flag (admittedly, rather uninteresting in +our sample). + +As you can see, running programs non-interactively has many +limitations. You cannot peek the virtual machine's memory contents, not +to mention stepping through your program's instructions or setting +breakpoints. Enter interactive mode. + +@node Interactive mode, Debugging, Non-interactive mode, Running the program +@comment node-name, next, previous, up +@subsection Interactive mode +@cindex interactive mode + +To enter the MIX virtual machine interactive mode, simply type + +@example +mixvm @key{RET} +@end example + +@noindent at your shell command prompt. This command enters the +@code{mixvm} command shell. You will be presented the following command +prompt: + +@example +MIX > +@end example + +@noindent The virtual machine is initialised and ready to accept your +commands. The @code{mixvm} command shell uses GNU's readline, so that +you have at your disposal command completion (using @key{TAB}) and +history functionality, as well as other line editing shortcuts common to +all utilities using this library (for a complete description of +readline's line editing usage, see @ref{Command Line +Editing,,,Readline}.) + +Usually, the first thing you will want to do is loading a compiled MIX +program into memory. This is acomplished by the @code{load} command, +which takes as an argument the name of the @file{.mix} file to be +loaded. Thus, typing + +@example +MIX > load hello @key{RET} +Program loaded. Start address: 3000 +MIX > +@end example + +@noindent will load @file{hello.mix} into the virtual machine's memory +and set the program counter to the address of the first instruction. You +can obtain the contents of the program counter using the command +@code{pc}: + +@example +MIX > pc +Current address: 3000 +MIX > +@end example + +After loading it, you are ready to run the program, using, as you surely +have guessed, the @code{run} command: + +@example +MIX > run +Running ... +MIXAL HELLO WORLD +... done +Elapsed time: 11 /Total program time: 11 (Total uptime: 11) +MIX > +@end example + +@noindent Note that now the timing statistics are richer. You obtain the +elapsed execution time (i.e., the time spent executing instructions +since the last breakpoint), the total execution time for the program up +to now (which in our case coincides with the elapsed time, since there +were no breakpoints), and the total uptime for the virtual machine (you +can load and run more than one program in the same session). After +running the program, the program counter will point to the address after +the one containing the @code{HLT} instruction. In our case, asking the +value of the program counter after executing the program will give us + +@example +MIX > pc +Current address: 3002 +MIX > +@end example + +@noindent You can check the contents of a memory cell giving its address +as an argument of the command @code{pmem}, like this + +@example +MIX > pmem 3001 +3001: + 00 00 00 02 05 (0000000133) +MIX > +@end example + +@noindent +and convince yourself that address 3001 contains the binary +representation of the instruction @code{HLT}. An address range of the +form FROM-TO can also be used as the argument of @code{pmem}: + +@example +MIX > pmem 3000-3006 +3000: + 46 58 00 19 37 (0786957541) +3001: + 00 00 00 02 05 (0000000133) +3002: + 14 09 27 01 13 (0237350989) +3003: + 00 08 05 13 13 (0002118477) +3004: + 16 00 26 16 19 (0268542995) +3005: + 13 04 00 00 00 (0219152384) +3006: + 00 00 00 00 00 (0000000000) +MIX > +@end example + +@noindent +In a similar manner, you can look at the contents of the MIX registers +and flags. For instance, to ask for the contents of the A register you +can type + +@example +MIX > preg A +rA: + 00 00 00 00 00 (0000000000) +MIX > +@end example + +@noindent +Use the comand @code{help} to obtain a list of all available commands, +and @code{help COMMAND} for help on a specific command, e.g. + +@example +MIX > help run +run Run loaded or given MIX code file. Usage: run [FILENAME] +MIX > +@end example + +@noindent +For a complete list of commands available at the MIX propmt, +@xref{mixvm}. In the following subsection, you will find a quick tour +over commands useful for debugging your programs. + +@node Debugging, , Interactive mode, Running the program +@comment node-name, next, previous, up +@subsection Debugging commands + +The interactive mode of @code{mixvm} lets you step by step execution of +programs as well as breakpoint setting. Use @code{next} to step through +the program, running its instructions one by one. To run our +two-instruction @file{hello.mix} sample you can do the following: + +@example +MIX > load hello +Program loaded. Start address: 3000 +MIX > pc +Current address: 3000 +MIX > next +MIXAL HELLO WORLD +Elapsed time: 1 /Total program time: 1 (Total uptime: 1) +MIX > pc +Current address: 3001 +MIX > next +End of program reached at address 3002 +Elapsed time: 10 /Total program time: 11 (Total uptime: 11) +MIX > pc +Current address: 3002 +MIX > next +MIXAL HELLO WORLD +Elapsed time: 1 /Total program time: 1 (Total uptime: 12) +MIX > +MIX > run +Running ... +... done +Elapsed time: 10 /Total program time: 11 (Total uptime: 22) +MIX > @end example +@noindent +(As an aside, the above sample also shows how the virtual machine +handles cummulative time statistics and automatic program restart). + +You can set a breakpoint at a given address using the command +@code{sbpa} (set breakpoint at address). When a breakpoint is set, +@code{run} will stop before executing the instruction at the given +address. Typing @code{run} again will resume program execution. Coming +back to our hello world example, we would have: + +@example +MIX > sbpa 3001 +Breakpoint set at address 3001 +MIX > run +Running ... +MIXAL HELLO WORLD +... stopped: breakpoint at line 8 (address 3001) +Elapsed time: 1 /Total program time: 1 (Total uptime: 23) +MIX > run +Running ... +... done +Elapsed time: 10 /Total program time: 11 (Total uptime: 33) +MIX > +@end example + +@noindent +Note that, since we compiled @file{hello.mixal} with debug info enabled +(the @code{-g} flag of @code{mixasm}), the virtual machine is able to +tell us the line in the source file corresponding to the breakpoint we +are setting. As a matter of fact, you can directly set breakpoints at +source code lines using the command @code{sbp LINE_NO}, e.g. + +@example +MIX > sbp 4 +Breakpoint set at line 7 +MIX > +@end example + +@noindent +@code{sbp} sets the breakpoint at the first meaningful source code line; +thus, in the above example we have requested a breakpoint at a line +which does not correspond to a MIX instruction and the breakpoint is set +at the first line containing a real instruction after the given one. To +unset breakpoints, use @code{cbpa ADDRESS} and @code{cbp LINE_NO}, or +@code{cabp} to remove all currently set breakpoints. + +MIXAL lets you define symbolic constants, either using the @code{EQU} +pseudoinstruction or starting an instruction line with a label (which +assigns to the label the value of the current memory address). Each +MIXAL program has, therefore, an associated symbol table which you can +inspect using the @code{psym} command. For our hello world sample, you +will obtain the following output: + +@example +MIX > psym +START: 3000 +TERM: 19 +MSG: 3002 +MIX > +@end example + +Other useful commands for debugging are @code{tron} (which turns on +tracing of executed intructions) and @code{weval} (which evaluates +w-expressions on the fly). For a complete description of all available +MIX commands, @xref{mixvm}. diff --git a/doc/mdk_index.texi b/doc/mdk_index.texi new file mode 100644 index 0000000..cb752f0 --- /dev/null +++ b/doc/mdk_index.texi @@ -0,0 +1,10 @@ +@node Concept Index, , Problems, Top +@unnumbered Concept Index + +@cindex tail recursion +@printindex cp + +@c @node MIXAL instructions, , Concept Index, Top +@comment node-name, next, previous, up +@c @unnumbered MIXAL instructions +@c @printindex fn diff --git a/doc/mdk_install.texi b/doc/mdk_install.texi new file mode 100644 index 0000000..78690ba --- /dev/null +++ b/doc/mdk_install.texi @@ -0,0 +1,180 @@ +@node Installing MDK, MIX and MIXAL tutorial, Introduction, Top +@comment node-name, next, previous, up +@chapter Installing @sc{mdk} + +@menu +* Download:: +* Requirements:: +* Basic installation:: +* Emacs support:: +* Special configure flags:: +@end menu + +@node Download, Requirements, Installing MDK, Installing MDK +@comment node-name, next, previous, up +@section Download the source tarball + +GNU @sc{mdk} is distributed as a source tarball available for download in +the following @acronym{URL}s: + +@itemize @bullet +@item +@url{ftp://ftp.gnu.org/pub/gnu/mdk} (or one of +@uref{http://www.gnu.org/prep/ftp.html, its mirrors}) +@item +@uref{http://sourceforge.net/project/showfiles.php?group_id=13897} +@end itemize + +The above sites contain the latest stable releases of @sc{mdk}. The +development branch is available at: + +@itemize @bullet +@item +@uref{http://sourceforge.net/cvs/?group_id=13897} +@end itemize + +After you have downloaded the source tarball, unpack it in a directory +of your choice using the command: + +@example +tar xfvz mdk-X.Y.tar.gz +@end example + +@noindent +where @var{X.Y} stands for the downloaded version (the current stable +release being version @value{VERSION}). + +@node Requirements, Basic installation, Download, Installing MDK +@comment node-name, next, previous, up +@section Requirements + +In order to build and install @sc{mdk}, you will need the following +libraries installed in your system: + +@itemize @minus +@item +@uref{http://www.gtk.org, GLIB 1.2.0} (required) +@item +@uref{http://www.gnu.org/software/flex/flex.html, GNU Flex 2.3} (required) +@item +@uref{http://www.gtk.org, GTK+ 1.2.0} (optional) +@item +@uref{ftp://ftp.gnome.org/pub/GNOME/stable/sources/libglade/, libglade} +(optional) +@item +GNU readline and history libraries (optional) +@end itemize + +If present, readline and history are used to provide command completion +and history management to the command line MIX virtual machine, @code{mixvm} +GTK+ and libglade are needed if you want to build the graphical +interface to the MIX virtual machine, @code{gmixvm}. + +@strong{Please note}: you need both the libraries @emph{and} the +headers; this means both the library package and the @file{-dev} package +if you do not compile your libraries yourself (ex: installing +@file{libgtk1.2} and @file{libgtk1.2-dev} on Debian). + +@node Basic installation, Emacs support, Requirements, Installing MDK +@comment node-name, next, previous, up +@section Basic installation + +@sc{mdk} uses GNU Autoconf and Automake tools, and, therefore, should +be built and installed without hassle using the following commands +inside the source directory: + +@example +./configure +make +make install +@end example + +@noindent +where the last one must be run as root. + +The first command, @code{configure}, will setup the makefiles for your +system. In particular, @code{configure} will look for GTK+ and libglade, +and, if they are present, will generate the appropiate makefiles for +building the @code{gmixvm} graphical user interface. Upon completion, +you should see a message with the configuration results like the +following: + +@example +*** GNU MDK 0.3 has been successfully configured. *** + +Type make to build the following utilities: + - mixasm (MIX assembler) + - mixvm (MIX virtual machine, with readline support) + - gmixvm (mixvm GTK+ GUI) +@end example + +@noindent +where the last line may be missing if you lack the above mentioned +libraries. + +The next command, @code{make}, will actually build the @sc{mdk} programs +in the following locations: + +@itemize @minus +@item +@file{mixutils/mixasm} +@item +@file{mixutils/mixvm} +@item +@file{mixgtk/gmixvm} +@end itemize + +You can run these programs from within their directories, but I +recommend you to install them in proper locations using @code{make +install} from a root shell. + +@node Emacs support, Special configure flags, Basic installation, Installing MDK +@comment node-name, next, previous, up +@section Emacs support + +@code{mixvm} can be run within an Emacs GUD buffer using the elisp +program @file{misc/mixvm.el}, kindly contributed by @value{PHILIP}. + +@file{mixvm.el} provides an interface between @sc{mdk}'s @code{mixvm} +and Emacs, via @acronym{GUD}. Place this file in your load-path, +optionally adding the following line to your @file{.emacs} file: + +@lisp +(autoload 'mixvm "mixvm" "mixvm/gud interaction" t) +@end lisp + + + +@node Special configure flags, , Emacs support, Installing MDK +@comment node-name, next, previous, up +@section Special configure flags + +You can fine tunning the configuration process using the following +switches with configure: + +@defopt --enable-gui[=yes|no] +@defoptx --disable-gui +Enables/disables the built of the MIX virtual machine GUI +(@code{gmixvm}). If the required libraries are missing +(@pxref{Requirements}) the configure script with automatically disable +this feature. +@end defopt + +@defopt --with-readline[=yes|no] +@defoptx --without-readline +Enables/disables the GNU Readline support for @code{mixvm}. If the +required libraries are missing (@pxref{Requirements}) the configure +script with automatically disable this feature. +@end defopt + +For additional, boilerplate configure options, see the @file{INSTALL} +file, or run + +@example +configure --help +@end example + + + + + diff --git a/doc/mdk_intro.texi b/doc/mdk_intro.texi new file mode 100644 index 0000000..2a3f95d --- /dev/null +++ b/doc/mdk_intro.texi @@ -0,0 +1,48 @@ +@node Introduction, Installing MDK, Top, Top +@comment node-name, next, previous, up +@unnumbered Introduction +@cindex Introduction + +In his book series @cite{The Art of Computer Programming} (published by +Addison Wesley), D. Knuth uses an imaginary computer, the MIX, and its +associated machine-code and assembly languages to ilustrate the +concepts and algorithms as they are presented. + +The MIX's architecture is a simplified version of those found in real +CISC CPUs, and the MIX assembly language (MIXAL) provides a set of +primitives that will be very familiar to any person with a minimum +experience in assembly programming. The MIX/MIXAL definition is powerful +and complete enough to provide a virtual development platform for +writing quite complex programs, and close enough to real computers to be +worth using when learning programming techniques. At any rate, if you +want to learn or improve your programming skills, a MIX development +environment would come in handy. + +The @sc{mdk} package aims at providing such virtual development +environment on a GNU box. Thus, @sc{mdk} offers you a set of utilities +to simulate the MIX computer and to write, compile, run and debug MIXAL +programs. As of version @value{VERSION}, @sc{mdk} includes +the following programs: + +@table @code +@item mixasm +MIXAL assembler. Assembler which translates MIXAL source files into +programs that can be run (and debugged) by @code{mixvm} or @code{gmixvm}. +@item mixvm +MIX virtual machine. Emulation of the MIX computer with a @acronym{CLI}. +@item gmixvm +A GTK+ GUI for the MIX virtual machine. Provides all of @code{mixvm} +functionality accessible through a graphical interface. +@item mixvm.el +This elisp program allows running @code{mixvm} inside an Emacs GUD +buffer, allowing concurrent edition and debugging of MIXAL programs. +@end table + +@code{mixvm} and @code{gmixvm} implement a simulator of the MIX +computer, giving you a virtual machine for executing and debugging MIX +programs. These binary programs could be written by hand, but it is +easier to produce them compiling MIXAL source files, using the MIXAL +assembler @code{mixasm}. + +This manual gives you a tutorial of MIX and MIXAL, and a thorough +description of the use of the @sc{mdk} utilities. diff --git a/doc/mdk_mixasm.texi b/doc/mdk_mixasm.texi new file mode 100644 index 0000000..753aa33 --- /dev/null +++ b/doc/mdk_mixasm.texi @@ -0,0 +1,79 @@ +@node mixasm, Copying, gmixvm, Top +@comment node-name, next, previous, up +@chapter @code{mixasm}, the MIXAL assembler +@cindex @code{mixasm} +@cindex MIXAL +@cindex assembler + +MIX programs, as executed by @code{mixvm}, are composed of binary +instructions loaded into the virtual machine memory as MIX +words. Although you could write your MIX programs directly as a series +of words in binary format, you have at your disposal a more friendly +assembly language, MIXAL (@pxref{MIXAL}) which is compiled into binary +form by @code{mixasm}, the MIXAL assembler included in @sc{mdk}. In this +chapter, you will find a complete description of @code{mixasm} options. + +@menu +* Invoking @code{mixasm}:: @code{mixasm} options +@end menu + +@node Invoking @code{mixasm}, , mixasm, mixasm +@comment node-name, next, previous, up +@section Invoking @code{mixasm} + +In its simplest form, @code{mixasm} is invoked with a single argument, +which is the name of the MIXAL file to be compiled, e.g. + +@example +mixasm hello +@end example + +@noindent +will compile either @file{hello} or @file{hello.mixal}, producing a +binary file named @file{hello.mix} if no errors are found. + +In addition, @code{mixasm} can be invoked with the following command +line options (note, that, following GNU's conventions, we provide a long +option name for each available single letter switch): + +@example +mixasm [-vhulg] [-o OUTPUT_FILE] [--version] [--help] + [--usage] [--debug] [--output=OUTPUT_FILE] [--list[=LIST_FILE]] file +@end example + +@noindent +The meaning of these options is as follows: + +@defopt -v +@defoptx --version +Prints version and copyleft information and exits. +@end defopt + +@defopt -h +@defoptx --help +@defoptx -u +@defoptx --usage +Prints a summary of available options and exits. +@end defopt + +@defopt -g +@defoptx --debug +Includes debugging information in the compiled file, allowing breakpoint +setting at source level and symbol table inspection under @code{mixvm}. +@end defopt + +@defopt -o output_file +@defoptx --output=output_file +By default, the given source file @var{file.mixal} is compiled into +@var{file.mix}. You can provide a different name for the output file +using this option. +@end defopt + +@defopt -l +@defoptx --list[=list_file] +This option causes @code{mixasm} to produce, in addion to the +@file{.mix} file, an ASCII file containing a summary of the compilation +results. The file is named after the MIXAL source file, changing its +extension to @file{.mls} if no argument is provided; otherwise, the +listing file is named according to the argument. +@end defopt diff --git a/doc/mdk_mixvm.texi b/doc/mdk_mixvm.texi new file mode 100644 index 0000000..8289472 --- /dev/null +++ b/doc/mdk_mixvm.texi @@ -0,0 +1,478 @@ +@node mixvm, gmixvm, mixvm.el, Top +@comment node-name, next, previous, up +@chapter @code{mixvm}, the MIX computer simulator + +@cindex mixvm + +This chapter describes @code{mixvm}, the MIX computer +simulator. @code{mixvm} is a command line interface programme which +simulates the MIX computer (@pxref{The MIX computer}). It is able +to run MIXAL programs (@pxref{MIXAL}) previously compiled with the MIX +assembler (@pxref{mixasm}). The simulator allows inspection of the MIX +computer components (registers, memory cells, comparison flag and overflow +toggle), step by step execution of MIX programmes, and breakpoint +setting to aid you in debugging your code. For a tutorial description of +@code{mixvm} usage, @xref{Running the program}. + +@menu +* Invocation:: Options when invoking @code{mixvm}. +* Commands:: Commands available in interactive mode. +* Devices:: MIX block devices implementation. +@end menu + +@node Invocation, Commands, mixvm, mixvm +@comment node-name, next, previous, up +@section Invoking @code{mixvm} + +@code{mixvm} can be invoked with the following command line options +(note, that, following GNU's conventions, we provide a long option name +for each available single letter switch): + +@example +mixvm [-vhurd] [--version] [--help] [--usage] [--run] [--dump] + [FILE[.mix]] +@end example + +@noindent +The meaning of these options is as follows: + +@defopt -v +@defoptx --version +Prints version and copyleft information and exits. +@end defopt + +@defopt -h +@defoptx --help +@defoptx -u +@defoptx --usage +Prints a summary of available options and exits. +@end defopt + +@defopt -r +@defoptx --run +Loads the specified @var{FILE} and executes it. After the program +execution, @code{mixvm} exits. @var{FILE} must be the name of a binary +@file{.mix} program compiled with @code{mixasm}. If your program does +not produce any output, use the @code{-d} flag (see below) to peek at +the virtual machine's state after execution. +@end defopt + +@defopt -d +@defoptx --dump +This option must be used in conjuction with @code{-r}, and tells +@code{mixvm} to print the value of the virtual machine's registers, +comparison flag and overflow toggle after executing the program named +@var{FILE}. See @xref{Non-interactive mode}, for sample usage. +@end defopt + +When run without the @code{-r} flag, @code{mixvm} enters its interactive +mode, showing you a prompt like this one: + +@example +MIX > +@end example + +@noindent +and waiting for your commands (@pxref{Commands}). If the +optional @var{FILE} argument is given, the file @file{FILE.mix} will be +loaded into the virtual machine memory before entering the interactive +mode. + +@node Commands, Devices, Invocation, mixvm +@comment node-name, next, previous, up +@section Interactive commands + +You can enter the interactive mode of the MIX virtual machine by simply +invoking @code{mixvm} without arguments. You will then presented a shell +prompt + +@example +MIX > +@end example + +@noindent +which indicates that a new virtual machine has been initialised and is +ready to execute your commands. As we have already mentioned, this +command prompt offers you command line editing facilities which are +described in the Readline user's manual (chances are that you are +already familiar with these command line editing capabilities, as they +are present in many GNU utilities, e.g. the @code{bash} shell). As a +beginner, your best friend will be the @code{help} command, which shows +you a summary of all available MIX commands and their usage; its syntax +is as follows: + +@deffn {@code{mixvm} command} help [command] +@deffnx {@code{mixvm} command} ? [command] +Prints a short description of the given @var{command} and its usage. If +@var{command} is omitted, all available commands are described. +@end deffn + +@menu +* File commands:: Loading and executing programs. +* Debug commands:: Debugging programs. +* State commands:: Inspecting the virtual machine state. +@end menu + +@node File commands, Debug commands, Commands, Commands +@comment node-name, next, previous, up +@subsection File commands + +You have at your disposal a series of commands that let you load and +execute MIX executable files, as well as manipulate MIXAL source files: + +@deffn {file command} load file[.mix] +This command loads a binary file, @var{file.mix} into the virtual +machine memory, and positions the program counter at the beginning of +the loaded program. This address is indicated in the MIXAL source file +as the operand of the @code{END} pseudoinstruction. Thus, if your +@file{sample.mixal} source file contains the line: + +@example + END 3000 +@end example + +@noindent +and you compile it with @code{mixasm} to produce the binary file +@file{sample.mix}, you will load it into the virtual machine as follows: + +@example +MIX > load sample +Program loaded. Start address: 3000 +MIX > +@end example + +@end deffn + +@deffn {file command} run [file[.mix]] +When executed without argument, this command initiates or resumes +execution of instructions from the current program counter +address. Therefore, issuing this command after a successful @code{load}, +will run the loaded program until either a @code{HLT} instruction or a +breakpoint is found. If you provide a MIX filename as argument, the +given file will be loaded (as with @code{load} @var{file}) and +executed. If @code{run} is invoked again after program execution +completion (i.e., after the @code{HLT} instruction has been found in a +previous run), the program counter is repositioned and execution starts +again from the beginning. +@end deffn + +@deffn {file command} edit file[.mixal] +The source file @var{file.mixal} is edited using the editor defined in +the environment variable @var{MDK_EDITOR}. If this variable is not set, +the following ones are tried out in order: @var{X_EDITOR}, @var{EDITOR} +and @var{VISUAL}. +@end deffn + +@deffn {file command} compile file[.mixal] +The source file @var{file.mixal} is compiled (with debug information +enabled) using @code{mixasm}. +@end deffn + + +@node Debug commands, State commands, File commands, Commands +@comment node-name, next, previous, up +@subsection Debug commands + +Sequential execution of loaded programs can be interrupted using the +following debug commands: + +@deffn {debug command} next [ins_number] +This command causes the virtual machine to fetch and execute up to +@var{ins_number} instructions, beginning from the current program +counter position. Execution is interrupted either when the specified +number of instructions have been fetched or a breakpoint is found, +whatever happens first. If run without arguments, one instruction is +executed. +@end deffn + +@deffn {debug command} sbp line_number +Sets a breakpoint at the specified source file line number. If the line +specified corresponds to a command or to a MIXAL pseudoinstruction which +does not produce a MIX instruction in the binary file (such as +@code{ORIG} or @code{EQU}) the breakpoint is set at the first source +code line giving rise to a MIX instruction after the specified +one. Thus, for our sample @file{hello.mixal} file: + +@example +* (1) +* hello.mixal: say 'hello world' in MIXAL (2) +* (3) +* label ins operand comment (4) +TERM EQU 19 the MIX console device number (5) + ORIG 1000 start address (6) +START OUT MSG(TERM) output data at address MSG (7) +... +@end example + +@noindent +trying to set a breakpoint at line 5, will produce the following result: + +@example +MIX > sbp 5 +Breakpoint set at line 7 +MIX > +@end example + +@noindent +since line 7 is the first one compiled into a MIX instruction (at +address 3000). In order to @code{sbp} to work, the source file must be +compiled using the @code{-g} flags, which tells @code{mixasm} to include +debug information in the binary @file{.mix} file. +@end deffn + +@deffn {debug command} spba address +Sets a breakpoint at the given memory @var{address}. The argument must +be a valid MIX memory address, i.e., it must belong into the range +@w{[0-3999]}. Note that no check is performed to verify that the +specified address is reachable during program execution. No debug +information is needed to set a breakpoint by address with @code{sbpa}. +@end deffn + +@deffn {debug command} cbp line_no +Clears a (previously set) breakpoint at the given source file line. +@end deffn + +@deffn {debug command} cbpa address +Clears a (previously set) breakpoint at the given memory address. +@end deffn + +@deffn {debug command} cabp +Clears all currently set breakpoints. +@end deffn + +@deffn {debug command} psym [symbol_name] +MIXAL programs can define symbolic constants, using either the +@code{EQU} pseudoinstruction or a label at the beginning of a +line. Thus, in the program fragment + +@example +VAR EQU 2168 + ORIG 4000 +START LDA VAR +@end example + +@noindent +the symbol @code{VAR} stands for the value 2168, while @code{START} is +assigned the value 4000. When MIXAL programs are compiled using the +@code{-g} flag (which tells @code{mixasm} to include debug information +in the binary @file{.mix} file), the symbol table can be consulted from +the @code{mixvm} command line using @code{psym} followed by the name of +the symbol whose contents you are interested in. When run without +arguments, @code{psym} will print all defined symbols and their values. +@end deffn + +The virtual machine can also show you the instructions it is executing, +using the following commands: + +@deffn {debug command} tron +@deffnx troff +@code{tron} enables instruction tracing. When tracing is enabled, each +time the virtual machine executes an instruction (due to your issuing a +@code{run} or @code{next} command), it is printed in its canonical form +(that is, with all expressions evaluated to their numerical values) and, +if the program was compiled with debug information, as it was originally +typed in the MIXAL source file. Instruction tracing is disable with the +@code{troff} command. A typical tracing session could be like this: + +@example +MIX > tron +Instruction tracing has been turned ON. +MIX > next +3000: [OUT 3002,0(2:3)] START OUT MSG(TERM) +MIXAL HELLO WORLD +Elapsed time: 1 /Total program time: 1 (Total uptime: 1) +MIX > next +3001: [HLT 0,0] HLT +End of program reached at address 3002 +Elapsed time: 10 /Total program time: 11 (Total uptime: 11) +MIX > troff +Instruction tracing has been turned OFF. +MIX > +@end example +@noindent +The executed instruction, as it was translated, is shown between square +brackets after the memory address, and, following it, you can see the +actual MIXAL code that was compiled into the executed instruction. +@end deffn + +@code{mixvm} is also able of evaluating w-expressions +(@pxref{W-expressions}) using the following command: + +@deffn {debug command} weval WEXP +Evaluates the given w-expression, @var{WEXP}. The w-expression can +contain any currently defined symbol. For instance: + +@example +MIX > psym START ++ 00 00 00 46 56 (0000003000) +MIX > weval START(0:1),START(3:4) ++ 56 00 46 56 00 (0939716096) +MIX > +@end example +@end deffn + +New symbols can be defined using the @code{ssym} command: +@deffn {debug command} ssym SYM WEXP +Defines the symbol named @var{SYM} with the value resulting from +evaluating @var{WEXP}, an w-expression. The newly defined symbol can be +used in subsequent @code{weval} commands, as part of the expression to +be evaluated. E.g., + +@example +MIX > ssym S 2+23*START ++ 00 00 18 19 56 (0000075000) +MIX > psym S ++ 00 00 18 19 56 (0000075000) +MIX > weval S(3:4) ++ 00 00 19 56 00 (0000081408) +MIX > +@end example +@end deffn + +Finally, if you want to discover which is the decimal value of a MIX +word expressed as five bytes plus sign, you can use + +@deffn {debug command} w2d WORD +Computes the decimal value of the given word. @var{WORD} must be +expressed as a sign (+/-) followed by five space-delimited, two-digit +decimal values representing the five bytes composing the word. The +reverse operation (showing the word representation of a decimal value) +can be accomplished with @code{weval}. For instance: + +@example +MIX > w2d - 01 00 00 02 02 +-16777346 +MIX > weval -16777346 +- 01 00 00 02 02 (0016777346) +MIX > +@end example +@end deffn + +@node State commands, , Debug commands, Commands +@comment node-name, next, previous, up +@subsection State commands + +Inspection and modification of the virtual machine state (memory, +registers, overflow toggle and comparison flag contents) is accomplished +using the following commands: + +@deffn {state command} pc +Prints the current value of the program counter, which stores the +address of the next instruction to be executed in a non-halted program. +@end deffn + +@deffn {state command} preg [A | X | J | I[1-6]] +@deffnx {state command} pall +@deffnx {state command} sreg A | X | J | I[1-6] value +@code{preg} prints the contents of a given MIX register. For instance, +@w{@code{preg} @var{A}} will print the contents of the A-register. When +invoked without arguments, all registers shall be printed: + +@example +MIX > preg +rA: - 00 00 00 00 35 (0000000035) +rX: + 00 00 00 15 40 (0000001000) +rJ: + 00 00 (0000) +rI1: + 00 00 (0000) rI2: + 00 00 (0000) +rI3: + 00 00 (0000) rI4: + 00 00 (0000) +rI5: + 00 00 (0000) rI6: + 00 00 (0000) +MIX > +@end example + +As you can see in the above sample, the contents is printed as the sign +plus the values of the MIX bytes stored in the register and, between +parenthesis, the decimal representation of its module. + +@code{pall} prints the contents of all registers plus the comparison +flag and overflow toggle. + +Finally, @code{sreg} Sets the contents of the given register to +@var{value}, expressed as a decimal constant. If @var{value} exceeds the +maximum value storable in the given register, @math{VALUE mod +MAXIMU_VALUE} is stored, e.g. + +@example +MIX > sreg I1 1000 +MIX > preg I1 +rI1: + 15 40 (1000) +MIX > sreg I1 1000000 +MIX > preg I1 +rI1: + 09 00 (0576) +MIX > +@end example + +@end deffn + + +@deffn {state command} pflags +@deffnx {state command} scmp E | G | L +@deffnx {state command} sover F | T +@code{pflags} prints the value of the comparison flag and overflow +toggle of the virtual machine, e.g. + +@example +MIX > pflags +Overflow: F +Cmp: E +MIX > +@end example + +@noindent +The values of the overflow toggle are either @var{F} (false) or @var{T} +(true), and, for the comparison flag, @var{E}, @var{G}, @var{L} (equal, +greater, lesser). @code{scmp} and @code{sover} are setters of the +comparison flag and overflow toggle values. +@end deffn + +@deffn {state command} pmem from[-to] +@deffnx {state command} smem address value +@code{pmem} prints the contents of memory cells in the address range +@w{[@var{FROM}-@var{TO}]}. If the upper limit @var{to} is omitted, only +the contents of the memory cell with address @var{FROM} is printed, as +in + +@example +MIX > pmem 3000 +3000: + 46 58 00 19 37 (0786957541) +MIX > +@end example + +The memory contents is displayed both as the set of five MIX bytes plus +sign composing the stored MIX word and, between parenthesis, the decimal +representation of the module of the stored value. + +@code{smem} sets the content of the memory cell with address +@var{address} to @var{value}, expressed as a decimal constant. + +@end deffn + +Finally, you can use the @code{quit} command to exit @code{mixvm}. + +@node Devices, , Commands, mixvm +@comment node-name, next, previous, up +@section MIX block devices + +The MIX computer comes equipped with a set of block devices for +input-output operations (@pxref{Input-output operators}). @code{mixvm} +implements these block devices as disk files, with the exception of +block device no. 19 (typewriter terminal) which is redirected to +standard output. When you request an output operation on any other +(output) device, a file named according to the following table will be +created in the current directory, and the specified MIX words will be +written to the file in binary form (for binary devices) or in ASCII (for +char devices). Files corresponding to input block devices should be +created and filled beforehand to be used by the MIX virtual machine (for +input-output devices this creation can be accomplished by a MIXAL +program writing to the device the required data, or, if you prefer, with +your favourite editor). + +@multitable {the device name} { xx-xx } {filename[x-x].dev} {bin i/o } +@item @emph{Device} @tab @emph{No.} @tab @emph{filename} @tab @emph{type} +@item Tape @tab 0-7 @tab @file{tape[0-7].dev} @tab bin i/o +@item Disks @tab 8-15 @tab @file{disk[0-7].dev} @tab bin i/o +@item Card reader @tab 16 @tab @file{cardrd.dev} @tab char in +@item Card writer @tab 17 @tab @file{cardwr.dev} @tab char out +@item Line printer @tab 18 @tab @file{printer.dev} @tab char out +@item Terminal @tab 19 @tab @code{stdout} @tab char out +@item Paper tape @tab 20 @tab @file{paper.dev} @tab char out +@end multitable diff --git a/doc/mdk_tut.texi b/doc/mdk_tut.texi new file mode 100644 index 0000000..12bfb42 --- /dev/null +++ b/doc/mdk_tut.texi @@ -0,0 +1,1259 @@ +@node MIX and MIXAL tutorial, Getting started, Installing MDK, Top +@comment node-name, next, previous, up +@chapter MIX and MIXAL tutorial +@cindex MIX +@cindex MIXAL + +In the book series @cite{The Art of Computer Programming}, by D. Knuth, +a virtual computer, the MIX, is used by the author (together with the +set of binary instructions that the virtual CPU accepts) to illustrate +the algorithms and skills that every serious programmer should +master. Like any other real computer, there is a symbolic assembler +language that can be used to program the MIX: the MIX assembly language, +or MIXAL for short. In the following subsections you will find a tutorial +on these topics, which will teach you the basics of the MIX architecture +and how to program a MIX computer using MIXAL. + +@menu +* The MIX computer:: Architecture and instruction set + of the MIX computer. +* MIXAL:: The MIX assembly language. +@end menu + +@node The MIX computer, MIXAL, MIX and MIXAL tutorial, MIX and MIXAL tutorial +@comment node-name, next, previous, up +@section The MIX computer + +In this section, you will find a description of the MIX computer, +its components and instruction set. + +@menu +* MIX architecture:: +* MIX instruction set:: +@end menu + +@node MIX architecture, MIX instruction set, The MIX computer, The MIX computer +@comment node-name, next, previous, up +@subsection MIX architecture +@cindex byte +@cindex MIX byte +@cindex word +@cindex MIX word +@cindex MIX architecture +@cindex MIX computer +@cindex register +@cindex MIX register +@cindex field specification +@cindex fspec +@cindex instruction +@cindex MIX instruction +@cindex address +@cindex memory cell +@cindex cell +@cindex memory +@cindex index + +The basic information storage unit in the MIX computer is the +@dfn{byte}, which stores positive values in the range 0-63 . Note that a +MIX byte can be then represented as 6 bits, instead of the common 8 bits +for a @emph{regular} byte. Unless otherwise stated, we shall use the +word @dfn{byte} to refer to a MIX 6-bit byte. + +A MIX @dfn{word} is defined as a set of 5 bytes plus a sign. The bytes +within a word are numbered from 1 to 5, being byte number one the most +significant one. The sign is denoted by index 0. Graphically, + +@example + ----------------------------------------------- +| 0 | 1 | 2 | 3 | 4 | 5 | + ----------------------------------------------- +| +/- | byte | byte | byte | byte | byte | + ----------------------------------------------- +@end example +@noindent +Sample MIX words are @samp{- 12 00 11 01 63} and @samp{+ 12 11 34 43 +00}. + +You can refer to subfields within a word using a @dfn{field +specification} or @dfn{fspec} of the form ``(@var{l}:@var{r})'', where +@var{l} denotes the first byte, and @var{r} the last byte of the +subfield. +When @var{l} is zero, the subfield includes the word's +sign. An fspec can also be represented as a single value @code{F}, given +by @code{F = 8*L + R} (thus the fspec @samp{(1:3)}, denoting the first +three bytes of a word, is represented by the integer 11). + +The MIX computer stores information in @dfn{registers}, that can store +either a word or two bytes and sign (see below), and @dfn{memory cells}, +each one containing a word. Specifically, the MIX computer has 4000 +memory cells with addresses 0 to 3999 (i.e., two bytes are enough to +address a memory cell) and the following registers: + +@cindex rA +@cindex rX +@cindex rJ +@cindex rIn +@cindex register + +@table @asis +@item @code{rA} +A register. General purpose register holding a word. Usually its +contents serves as the operand of arithmetic and storing instructions. +@item @code{rX} +X register. General purpose register holding a word. Often it acts as an +extension or a replacement of @samp{rA}. +@item @code{rJ} +J (jump) register. This register stores positive two-byte values, +usually representing a jump address. +@item @code{rI1}, @code{rI2}, @code{rI3}, @code{rI4}, @code{rI5}, @code{rI6} +Index registers. These six registers can store a signed two-byte +value. Their contents is used as indexing values for the computation of +effective memory addresses. +@end table + +@cindex @sc{ov} +@cindex @sc{cm} +@cindex @code{un} +@cindex overflow toggle +@cindex comparison indicator +@cindex input-output devices +@noindent +In addition, the MIX computer contains: + +@itemize @minus +@item +An @dfn{overflow toggle} (a single bit with values @dfn{on} or +@dfn{off}). In this manual, this toggle is denoted @sc{ov}. +@item +A @dfn{comparison indicator} (having three values: @dfn{EQUAL}, +@dfn{GREATER} or @dfn{LESS}). In this manual, this indicator is denoted +@sc{cm}, and its possible values are abbreviated as @dfn{E}, @dfn{G} and +@dfn{L}. +@item +Input-output block devices. Each device is labelled as @code{un}, where +@code{n} runs from 0 to 20. In Knuth's definition, @code{u0} through +@code{u7} are magnetic tape units, @code{u8} through @code{15} are disks +and drums, @code{u16} is a card reader, @code{u17} is a card writer, +@code{u18} is +a line printer and, @code{u19} is a typewriter terminal, and @code{u20}, +a paper tape. Our implementation maps these devices to disk files, +except for @code{u19}, which represents the standard output. +@end itemize + +As noted above, the MIX computer communicates with the external world by +a set of input-output devices which can be ``connected'' to it. The +computer interchanges information using blocks of words whose length +depends on the device at hand (@pxref{Devices}). These words are +interpreted by the device either as binary information (for devices +0-16), or as representing printable characters (devices 17-20). In the +last case, each MIX byte is mapped onto a character according to the +following table: + +@multitable {00} {C} {00} {C} {00} {C} {00} {C} +@item 00 @tab @tab 01 @tab A @tab 02 @tab B @tab 03 @tab C +@item 04 @tab D @tab 05 @tab E @tab 06 @tab F @tab 07 @tab G +@item 08 @tab H @tab 09 @tab I @tab 10 @tab d @tab 11 @tab J +@item 12 @tab K @tab 13 @tab L @tab 14 @tab M @tab 15 @tab N +@item 16 @tab O @tab 17 @tab P @tab 18 @tab Q @tab 19 @tab R +@item 20 @tab s @tab 21 @tab p @tab 22 @tab S @tab 23 @tab T +@item 24 @tab U @tab 25 @tab V @tab 26 @tab W @tab 27 @tab X +@item 28 @tab Y @tab 29 @tab Z @tab 30 @tab 0 @tab 31 @tab 1 +@item 32 @tab 2 @tab 33 @tab 3 @tab 34 @tab 4 @tab 35 @tab 5 +@item 36 @tab 6 @tab 37 @tab 7 @tab 38 @tab 8 @tab 39 @tab 9 +@item 40 @tab . @tab 41 @tab , @tab 42 @tab ( @tab 43 @tab ) +@item 44 @tab + @tab 45 @tab - @tab 46 @tab * @tab 47 @tab / +@item 48 @tab = @tab 49 @tab $ @tab 50 @tab < @tab 51 @tab > +@item 52 @tab @@ @tab 53 @tab ; @tab 54 @tab : @tab 55 @tab ' +@end multitable +@noindent +The value 0 represents a whitespace. Lowercase letters (d, s, p) +correspond to symbols not representable as ASCII characters (uppercase +delta, sigma and gamma, respectively), and byte values 56-63 have no +associated character. + +Finally, the MIX computer features a virtual CPU which controls the +above components, and which is able to execute a rich set of +instructions (constituting its machine language, similar to those +commonly found in real CPUs), including arithmetic, logical, storing, +comparison and jump instructions. Being a typical von Neumann computer, +the MIX CPU fetchs binary instructions from memory sequentially (unless +a jump instruction is found), and stores the address of the next +instruction to be executed in an internal register called @dfn{location +counter} (also known as program counter in other architectures). + +The next section, @xref{MIX instruction set}, gives a complete description +of the available MIX binary instructions. + +@node MIX instruction set, , MIX architecture, The MIX computer +@comment node-name, next, previous, up +@subsection MIX instruction set +@cindex instruction set + +The following subsections fully describe the instruction set of the MIX +computer. We begin with a description of the structure of binary +instructions and the notation used to refer to their subfields. The +remaininig subsections are devoted to describing the actual instructions +available to the MIX programmer. + +@menu +* Instruction structure:: +* Loading operators:: +* Storing operators:: +* Arithmetic operators:: +* Address transfer operators:: +* Comparison operators:: +* Jump operators:: +* Input-output operators:: +* Conversion operators:: +* Shift operators:: +* Miscellaneous operators:: +* Execution times:: +@end menu + +@node Instruction structure, Loading operators, MIX instruction set, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Instruction structure + +MIX @dfn{instructions} are codified as words with the following subfield +structure: + +@multitable @columnfractions .15 .20 .65 +@item @emph{Subfield} @tab @emph{fspec} @tab @emph{Description} +@item ADDRESS @tab (0:2) +@tab The first two bytes plus sign are the @dfn{address} field. Combined +with the INDEX field, denotes the memory address to be used by the +instruction. +@item INDEX @tab (3:3) +@tab The third byte is the @dfn{index}, normally used for indexing the +address@footnote{The actual memory address the instruction refers to, is +obtained by adding to ADDRESS the value of the @samp{rI} register +denoted by INDEX.}. +@item MOD @tab (4:4) +@tab Byte four is used either as an operation code modifier or as a field +specification. +@item OPCODE @tab (5:5) +@tab The last (least significant) byte in the word denotes the operation +code. +@end multitable + +@noindent +or, graphically, + +@example + ------------------------------------------------ +| 0 | 1 | 2 | 3 | 4 | 5 | + ------------------------------------------------ +| ADDRESS | INDEX | MOD | OPCODE | + ------------------------------------------------ +@end example + +For a given instruction, @samp{M} stands for +the memory address obtained after indexing the ADDRESS subfield +(using its INDEX byte), and @samp{V} is the contents of the +subfield indicated by MOD of the memory cell with address @samp{M}. For +instance, suppose that we have the following contents of MIX registers +and memory cells: + +@example +[rI2] = + 00 63 +[31] = - 10 11 00 11 22 +@end example +@noindent +where @samp{[n]} denotes the contents of the nth memory cell and +@samp{[rI2]} the contents of register @samp{rI2}@footnote{In general, +@samp{[X]} will denote the contents of entity @samp{X}; thus, by +definition, @w{@samp{V = [M](MOD)}}.}. Let us consider the binary +instruction @w{@samp{I = - 00 32 02 11 10}}. For this instruction we +have: + +@example +ADDRESS = - 00 32 = -32 +INDEX = 02 = 2 +MOD = 11 = (1:3) +OPCODE = 10 + +M = ADDRESS + [rI2] = -32 + 63 = 31 +V = [M](MOD) = (- 10 11 00 11 22)(1:3) = + 00 00 10 11 00 +@end example + +In the following subsections, we will assing to each MIX instruction a +mnemonic, or symbolic name. For instance, the mnemonic of @samp{OPCODE} +10 is @samp{LD2}. Thus we can rewrite the above instruction as + +@example +LD2 -32,2(1:3) +@end example +@noindent +or, for a generic instruction: + +@example +MNEMONIC ADDRESS,INDEX(MOD) +@end example +@noindent +Some instructions are identified by both the OPCODE and the MOD +fields. In these cases, the MOD will not appear in the above symbolic +representation. Also when ADDRESS or INDEX are zero, they can be +omitted. Finally, MOD defaults to (0:5) (meaning the +whole word). + +@node Loading operators, Storing operators, Instruction structure, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Loading operators +@cindex loading operators + +The following instructions are used to load memory contents into a +register. + +@ftable @code +@item LDA +Put in rA the contents of cell no. M. +OPCODE = 8, MOD = fspec. @code{rA <- V}. +@item LDX +Put in rX the contents of cell no. M. +OPCODE = 15, MOD = fspec. @code{rX <- V}. +@item LDi +Put in rIi the contents of cell no. M. +OPCODE = 8 + i, MOD = fspec. @code{rIi <- V}. +@item LDAN +Put in rA the negative contents of cell no. M. +OPCODE = 16, MOD = fspec. @code{rA <- -V}. +@item LDXN +Put in rX the negative contents of cell no. M. +OPCODE = 23, MOD = fspec. @code{rX <- -V}. +@item LDiN +Put in rIi the negative contents of cell no. M. +OPCODE = 16 + i, MOD = fspec. @code{rIi <- -V}. +@end ftable + +In all the above load instructions the @samp{MOD} field selects the +bytes of the memory cell with address @samp{M} which are loaded into the +requisite register (indicated by the @samp{OPCODE}). For instance, the +word @w{@samp{+ 00 13 01 27 11}} represents the instruction + +@example +LD3 13,1(3:3) + ^ ^ ^ ^ + | | | | + | | | --- MOD = 27 = 3*8 + 7 + | | --- INDEX = 1 + | --- ADDRESS = 00 13 + --- OPCODE = 11 +@end example +Let us suppose that, prior to this instruction execution, the state of +the MIX computer is the following: + +@example +[rI1] = - 00 01 +[rI3] = + 24 12 +[12] = - 01 02 03 04 05 +@end example +@noindent +As, in this case, @w{@samp{M = 13 + [rI1] = 12}}, we have +@w{@samp{V = [M](3:3) = (- 01 02 03 04 05)(3:3) = + 00 00 00 00 03}} +(note that the specified subfield is left-padded with null bytes to +complete a word). Hence, the MIX state, after the instruction execution, +will be + +@example +[rI1] = - 00 01 +[rI3] = + 00 03 +[12] = - 01 02 03 04 05 +@end example + +To further illustrate loading operators, the following table shows the +contents of @samp{rX} after different @samp{LDX} instructions: + +@table @samp +@item LDX 12(0:0) [rX] = - 00 00 00 00 00 +@item LDX 12(0:1) [rX] = - 00 00 00 00 01 +@item LDX 12(3:5) [rX] = + 00 00 03 04 05 +@item LDX 12(3:4) [rX] = + 00 00 00 03 04 +@item LDX 12(0:5) [rX] = - 01 02 03 04 05 +@end table + + +@node Storing operators, Arithmetic operators, Loading operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Storing operators +@cindex storing operators + +The following instructions are the inverse of the load +operations: they are used to store a subfield of a register +into a memory location. Here, MOD represents the subfield of the memory +cell that is to be overwritten with bytes from a register. These bytes +are taken beginning by the rightmost side of the register. + +@ftable @code +@item STA +Store rA. OPCODE = 24, MOD = fspec. @code{V <- rA}. +@item STX +Store rX. OPCODE = 31, MOD = fspec. @code{V <- rX}. +@item STi +Store rIi. OPCODE = 24 + i, MOD = fspec. @code{V <- rIi}. +@item STJ +Store rJ. OPCODE = 32, MOD = fspec. @code{V <- rJ}. +@item STZ +Store zero. OPCODE = 33, MOD = fspec. @code{V <- 0}. +@end ftable + +By way of example, consider the instruction @samp{STA 1200(2:3)}. It +causes the MIX to fetch bytes no. 4 and 5 of register A and copy them to +bytes 2 and 3 of memory cell no. 1200 (remember that, for these +instructions, MOD specifies a subfield of @emph{the memory +address}). The others bytes of the memory cell retain their +values. Thus, if prior to the instruction execution we have + +@example +[1200] = - 20 21 22 23 24 +[rA] = + 01 02 03 04 05 +@end example +@noindent +we will end up with + +@example +[1200] = - 20 04 05 23 24 +[rA] = + 01 02 03 04 05 +@end example + +As a second example, @samp{ST2 1000(0)} will set the sign of +@samp{[1000]} to that of @samp{[rI2]}. + +@node Arithmetic operators, Address transfer operators, Storing operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Arithmetic operators +@cindex arithmetic operators + +The following instructions perform arithmetic operations between rA and +rX register and memory contents. + +@ftable @code +@item ADD +Add and set OV if overflow. OPCODE = 1, MOD = fspec. +@w{@code{rA <- rA +V}}. +@item SUB +Sub and set OV if overflow. OPCODE = 2, MOD = fspec. +@w{@code{rA <- rA - V}}. +@item MUL +Multiply V times rA and store the 10-bytes product in rAX. +OPCODE = 3, MOD = fspec. @w{@code{rAX <- rA x V}}. +@item DIV +rAX is considered a 10-bytes number, and it is divided by V. +OPCODE = 4, MOD = fspec. @w{@code{rA <- rAX / V}}, @code{rX} <- reminder. +@end ftable + +In all the above instructions, @samp{[rA]} is one of the operands +of the binary arithmetic operation, the other being @samp{V} (that is, +the specified subfield of the memory cell with address @samp{M}), padded +with zero bytes on its left-side to complete a word. In multiplication +and division, the register @samp{X} comes into play as a right-extension +of the register @samp{A}, so that we are able to handle 10-byte numbers +whose more significant bytes are those of @samp{rA} (the sign of this +10-byte number is that of @samp{rA}: @samp{rX}'s sign is ignored). + +Addition and substraction of MIX words can give rise to overflows, since +the result is stored in a register with room to only 5 bytes (plus +sign). When this occurs, the operation result modulo @w{1,073,741,823} +(the maximum value storable in a MIX word) is stored in @samp{rA}, and +the overflow toggle is set to TRUE. + +@node Address transfer operators, Comparison operators, Arithmetic operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Address transfer operators +@cindex address transfer operators + +In these instructions, @samp{M} (the address of the instruction after +indexing) is used as a number instead of as the address of a memory +cell. + +@ftable @code +@item ENTA +Enter [rA]. OPCODE = 48, MOD = 2. @code{rA <- M}. +@item ENTX +Enter [rX]. OPCODE = 55, MOD = 2. @code{rX <- M}. +@item ENTi +Enter [rIi]. OPCODE = 48 + i, MOD = 2. @code{rIi <- M}. +@item ENNA +Enter negative [rA]. OPCODE = 48, MOD = 3. @code{rA <- -M}. +@item ENNX +Enter negative [rX]. OPCODE = 55, MOD = 3. @code{rX <- -M}. +@item ENNi +Enter negative [rIi]. OPCODE = 48 + i, MOD = 3. @code{rIi <- -M}. +@item INCA +Increase [rA]. OPCODE = 48, MOD = 0. @code{rA <- rA + M}. +@item INCX +Increase [rX]. OPCODE = 55, MOD = 0. @code{rX <- rX + M}. +@item INCi +Increase [rIi]. OPCODE = 48 + i, MOD = 0. @code{rIi <- rIi + M}. +@item DECA +Decrease [rA]. OPCODE = 48, MOD = 1. @code{rA <- rA - M}. +@item DECX +Decrease [rX]. OPCODE = 55, MOD = 0. @code{rX <- rX - M}. +@item DECi +Decrease [rIi]. OPCODE = 48 + i, MOD = 0. @code{rIi <- rIi - M}. +@end ftable + +In the above instructions, the subfield @samp{ADDRESS} acts as an +immediate (indexed) operand, and allow us to set directly the contents +of the MIX registers without an indirection to the memory cells (in a +real CPU this would mean that they are faster that the previously +discussed instructions, whose operands are fetched from memory). So, if +you want to store in @samp{rA} the value -2000 (- 00 00 00 31 16), you +can use the binary instruction @w{+ 31 16 00 03 48}, or, symbolically, + +@example +ENNA 2000 +@end example +@noindent +Used in conjuction with the store operations (@samp{STA}, @samp{STX}, +etc.), these instructions also allow you to set memory cells contents to +concrete values. + +Note that in these address transfer operators, the @samp{MOD} field is +not a subfield specificator, but serves to define (together with +@samp{OPCODE}) the concrete operation to be performed. + +@node Comparison operators, Jump operators, Address transfer operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Comparison operators +@cindex comparison operators + +So far, we have learned how to move values around between the MIX +registers and its memory cells, and also how to perform arithmetic +operations using these values. But, in order to write non-trivial +programs, other functionalities are needed. One of the most common is +the ability to compare two values, which, combined with jumps, will +allow the execution of conditional statements. +The following instructions compare the value of a register with @samp{V}, and +set the @sc{cm} indicator to the result of the comparison (i.e. to +@samp{E}, @samp{G} or @samp{L}, equal, greater or lesser respectively). + +@ftable @code +@item CMPA +Compare [rA] with V. OPCODE = 56, MOD = fspec. +@item CMPX +Compare [rX] with V. OPCODE = 63, MOD = fspec. +@item CMPi +Compare [rIi] with V. OPCODE = 56 + i, MOD = fspec. +@end ftable + +As explained above, these instructions modify the value of the MIX +comparison indicator; but maybe you are asking yourself how do you use +this value: enter jump operators, in the next subsection. + +@node Jump operators, Input-output operators, Comparison operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Jump operators +@cindex jump operators + +The MIX computer has an internal register, called the @dfn{location +counter}, which stores the address of the next instruction to be fetched +and executed by the virtual CPU. You cannot directly modify the contents +of this internal register with a load instruction: after fetching the +current instruction from memory, it is automatically increased in one +unit by the MIX. However, the is a set of instructions (which we call +jump instructions) which can alter the contents of the location counter +provided some condition is met. When this occurs, the value of the next +instruction address that would have been fetched in the absence of the +jump is stored in @samp{rJ} (except for @code{JSJ}), and the location +counter is set to the value of @samp{M} (so that the next instruction is +fetched from this new address). Later on, you can return to the point +when the jump occurred reading the address stored in @samp{rJ}. + +The MIX computer provides the following jump instructions: +With these instructions you force a jump to the specified address. Use +@samp{JSJ} if you do not care about the return address. + +@ftable @code +@item JMP +Unconditional jump. OPCODE = 39, MOD = 0. +@item JSJ +Unconditional jump, but rJ is not modified. OPCODE = 39, MOD = 1. +@end ftable + +These instructions check the overflow toggle to decide whether to jump +or not. + +@ftable @code +@item JOV +Jump if OV is set (and turn it off). OPCODE = 39, MOD = 2. +@item JNOV +Jump if OV is not set (and turn it off). OPCODE = 39, MOD = 3. +@end ftable + +In the following instructions, the jump is conditioned to the contents of the +comparison flag: + +@ftable @code +@item JL +Jump if @w{@code{[CM] = L}}. OPCODE = 39, MOD = 4. +@itemx JE +Jump if @w{@code{[CM] = E}}. OPCODE = 39, MOD = 5. +@itemx JG +Jump if @w{@code{[CM] = G}}. OPCODE = 39, MOD = 6. +@itemx JGE +Jump if @code{[CM]} does not equal @code{L}. OPCODE = 39, MOD = 7. +@itemx JNE +Jump if @code{[CM]} does not equal @code{E}. OPCODE = 39, MOD = 8. +@itemx JLE +Jump if @code{[CM]} does not equal @code{G}. OPCODE = 39, MOD = 9. +@end ftable + +You can also jump conditioned to the value stored in the MIX registers, +using the following instructions: + +@ftable @code +@item JAN +@itemx JAZ +@itemx JAP +@itemx JANN +@itemx JANZ +@itemx JANP +Jump if the contents of rA is, respectively, negative, zero, positive, +non-negative, non-zero or non-positive. +OPCODE = 40, MOD = 0, 1, 2, 3, 4, 5. +@item JXN +@itemx JXZ +@itemx JXP +@itemx JXNN +@itemx JXNZ +@itemx JXNP +Jump if the contents of rX is, respectively, negative, zero, positive, +non-negative, non-zero or non-positive. +OPCODE = 47, MOD = 0, 1, 2, 3, 4, 5. +@item JiN +@itemx JiZ +@itemx JiP +@itemx JiNN +@itemx JiNZ +@itemx JiNP +Jump if the contents of rIi is, respectively, negative, zero, positive, +non-negative, non-zero or non-positive. +OPCODE = 40 + i, MOD = 0, 1, 2, 3, 4, 5. +@end ftable + + +@node Input-output operators, Conversion operators, Jump operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Input-output operators +@cindex input-output operators + +As explained in previous sections (@pxref{MIX architecture}), the MIX +computer can interact with a series of block devices. To that end, you +have at your disposal the following instructions: + +@ftable @code +@item IN +Transfer a block of words from the specified unit to memory, starting at +address M. +OPCODE = 36, MOD = I/O unit. +@item OUT +Transfer a block of words from memory (starting at address M) to the +specified unit. +OPCODE = 37, MOD = I/O unit. +@item IOC +Perfom a control operation (given by M) on the specified unit. +OPCODE = 35, MOD = I/O unit. +@item JRED +Jump to M if the specified unit is ready. +OPCODE = 38, MOD = I/O unit. +@item JBUS +Jump to M if the specified unit is busy. +OPCODE = 34, MOD = I/O unit. +@end ftable +@noindent +In all the above instructions, the @samp{MOD} subfile must be in the +range 0-20, since it denotes the operation's target device. The +@samp{IOC} instruction only makes sense for tape devices (@samp{MOD} = +0-7 or 20): it shifts the read/write pointer by the number of words +given by @samp{M} (if it equals zero, the tape is rewound)@footnote{In +Knuth's original definition, there are other control operations +available, but they do not make sense when implementing the block +devices as disk files (as we do in @sc{mdk} simulator). For the same +reason, @sc{mdk} devices are always ready, since all input-output +operations are performed using synchronous system calls.}. + + +@node Conversion operators, Shift operators, Input-output operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Conversion operators +@cindex conversion operators + +The following instructions convert between numerical values and their +character representations. + +@ftable @code +@item NUM +Convert rAX, assumed to contain a character representation of a number, +to its numerical value and store it in rA. +OPCODE = 5, MOD = 0. +@item CHAR +Convert the number stored in rA to a character representation and store +it in rAX. +OPCODE = 5, MOD = 1. +@end ftable +@noindent +Digits are represented in MIX by the range of values 30-39 (digits +9-0). Thus, if the contents of @samp{rA} and @samp{rX} is, for instance, + +@example +[rA] = + 30 30 31 32 33 +[rX] = + 31 35 39 30 34 +@end example +@noindent +the represented number is 0012315904, and @samp{NUM} will store this +value in @samp{rA} (i.e., we end up with @samp{[rA]} = @w{+ 0 46 62 52 +0} = 12315904. @samp{CHAR} performs the inverse operation. + +@node Shift operators, Miscellaneous operators, Conversion operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Shift operators +@cindex shift +@cindex shift operators + +The following instructions perform byte-wise shifts of the contents of +@samp{rA} and @samp{rX}. + +@ftable @code +@item SLA +@itemx SRA +@itemx SLAX +@itemx SRAX +@itemx SLC +@itemx SRC +Shift rA or rAX left, right, or rAX circularly left or right. M +specifies the number of bytes to be shifted. +OPCODE = 6, MOD = 0, 1, 2, 3, 4, 5. +@end ftable +@noindent +If we begin with, say, @samp{[rA]} = @w{- 01 02 03 04 05}, we would +have the following modifications to @samp{rA} contents when performing +the instructions on the left column: + +@multitable {SLA 00} {[rA] = - 00 00 00 00 00} +@item SLA 2 @tab [rA] = - 03 04 05 00 00 +@item SRA 1 @tab [rA] = - 00 01 02 03 04 +@item SLC 3 @tab [rA] = - 04 05 01 02 03 +@item SRC 24 @tab [rA] = - 05 01 02 03 04 +@end multitable +@noindent +Note that the sign is unaffected by shift operations. On the other hand, +@samp{SLAX} and @samp{SRAX} treat @samp{rA} and @samp{rX} as a single +10-bytes register (ignoring again the signs), so that, if we begin with +@samp{[rA]} = @w{+ 01 02 03 04 05} and @samp{[rX]} = @w{- 06 07 08 09 +10}, executing @samp{SLAX 3} would yield: + +@example +[rA] = + 04 05 06 07 08 [rX] = - 09 10 00 00 00 +@end example + +@node Miscellaneous operators, Execution times, Shift operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Miscellaneous operators +@cindex miscellaneous operators + +Finally, we list in the following table three miscellaneous MIX +instructions which do not fit in any of the previous subsections: + +@ftable @code +@item MOVE +Move MOD words from M to the location stored in rI1. +OPCODE = 7, MOD = no. of bytes. +@item NOP +No operation. OPCODE = 0, MOD = 0. +@item HLT +Halt. Stops instruction fetching. OPCODE = 5, MOD = 2. +@end ftable +@noindent +The only effect of executing @samp{NOP} is increasing the location +counter, while @samp{HLT} usually marks program termination. + +@node Execution times, , Miscellaneous operators, MIX instruction set +@comment node-name, next, previous, up +@subsubsection Execution times + +@cindex exection time +@cindex time + +When writing MIXAL programs (or any kind of programs, for that matter), +whe shall often be interested in their execution time. Loosely speaking, +we will interested in the answer to the question: how long takes a +program to execute? Of course, this execution time will be a function of +the input size, and the answer to our question is commonly given as the +asymptotic behaviour as a function of the input size. At any rate, to +compute this asymptotic behaviour, we need a measure of how long +execution of a single instruction takes in our (virtual) CPU. Therefore, +each MIX instruction will have an associated execution time, given in +arbitrary units (in a real computer, the value of this unit will depend +on the hardware configuration). When our MIX virtual machine executes +programs, it will give you the value of their execution time based upon +the execution time of each single instruction. + +In the following table, the execution times (in the above mentioned +arbitrary units) of the MIX instructions are given. + +@multitable {INSSSS} {01} {INSSSS} {01} {INSSSS} {01} {INSSSS} {01} +@item @code{NOP} @tab 1 @tab @code{ADD} @tab 2 @tab @code{SUB} +@tab 2 @tab @code{MUL} @tab 10 +@item @code{DIV} @tab 12 @tab @code{NUM} @tab 10 @tab @code{CHAR} +@tab 10 @tab @code{HLT} @tab 10 +@item @code{SLx} @tab 2 @tab @code{SRx} @tab 2 @tab @code{LDx} +@tab 2 @tab @code{STx} @tab 2 +@item @code{JBUS} @tab 1 @tab @code{IOC} @tab 1 @tab @code{IN} +@tab 1@tab @code{OUT} @tab 1 +@item @code{JRED} @tab 1 @tab @code{Jx} @tab 1 @tab @code{INCx} +@tab 1 @tab @code{DECx} @tab 1 +@item @code{ENTx} @tab 1 @tab @code{ENNx} @tab 1 @tab @code{CMPx} +@tab 1 @tab @code{MOVE} @tab 1+F +@end multitable + +In the above table, 'F' stands for the number of blocks to be moved +(given by the @code{FSPEC} subfield of the instruction); @code{SLx} and +@code{SRx} are a short cut for the byte-shifting operations; @code{LDx} +denote all the loading operations; @code{STx} are the storing +operations; @code{Jx} stands for all the jump operations, and so on with +the rest of abbreviations. + +@node MIXAL, , The MIX computer, MIX and MIXAL tutorial +@comment node-name, next, previous, up +@section MIXAL +@cindex MIXAL +@cindex MIX assembly language +@cindex assembly + +In the previous sections we have listed all the available MIX binary +instructions. As we have shown, each instruction is represented by a +word which is fetched from memory and executed by the MIX virtual +CPU. As is the case with real computers, the MIX knows how to decode +instructions in binary format (the so--called machine language), but a +human programmer would have a tough time if she were to write her +programs in machine language. Fortunately, the MIX computer can be +programmed using an assembly language, MIXAL, which provides a symbolic +way of writing the binary instructions understood by the imaginary MIX +computer. If you have used assembler languages before, you will find +MIXAL a very familiar language. MIXAL source files are translated +to machine language by a MIX assembler, which produces a binary file (the +actual MIX program) which can be directly loaded into the MIX memory and +subsequently executed. + +In this section, we describe MIXAL, the MIX assembly language. The +implementation of the MIX assembler program and MIX computer simulator +provided by @sc{mdk} are described later on (@pxref{Getting started}). + +@menu +* Basic structure:: Writing basic MIXAL programs. +* MIXAL directives:: Assembler directives. +* Expressions:: Evaluation of expressions. +* W-expressions:: Evaluation of w-expressions. +* Local symbols:: Special symbol table entries. +* Literal constants:: Specifying an immediate operand. +@end menu + +@node Basic structure, MIXAL directives, MIXAL, MIXAL +@comment node-name, next, previous, up +@subsection Basic program structure + +The MIX assembler reads MIXAL files line by line, producing, when +required, a binary instruction, which is associated to a predefined +memory address. To keep track of the current address, the assembler +maintains an internal location counter which is incremented each time an +instruction is compiled. In addition to MIX instructions, you can +include in MIXAL file assembly directives (or pseudoinstructions) +addressed at the assembler itself (for instance, telling it where the +program starts and ends, or to reposition the location counter; see below). + +MIX instructions and assembler directives@footnote{We shall call them, +collectively, MIXAL instructions.} are written in MIXAL (one per +source file line) according to the following pattern: + +@example +[LABEL] MNEMONIC [OPERAND] [COMMENT] +@end example + +@noindent +where @samp{OPERAND} is of the form + +@example +[ADDRESS][,INDEX][(MOD)] +@end example + +Items between square brackets are optional, and + +@table @code +@item LABEL +Is an alphanumeric identifier (a @dfn{symbol}) which gets the current +value of the location counter, and can be used in subsequent +expressions. +@item MNEMONIC +Is a literal denoting the operation code of the instruction +(e.g. @code{LDA}, @code{STA}; see @pxref{MIX instruction set}) or an +assembly pseudoinstruction (e.g. @code{ORG}, @code{EQU}). +@item ADDRESS +Expression evaluating to the address subfield of the instruction. +@item INDEX +Expression evaluating to the index subfield of the instruction. It +defaults to 0 (i.e., no use of indexing) and can only be used when +@code{ADDRESS} is present. +@item MOD +Expression evaluating to the mod subfield of the instruction. Its +default value, when omitted, depends on @code{OPCODE}. +@item COMMENT +Any number of spaces after the operand mark the beggining of a comment, +i.e. any text separated by white space from the operand is ignored by +the assembler (note that spaces are not allowed within the +@samp{OPERAND} field). +@end table + +Note that spaces are @emph{not} allowed between the @code{ADDRESS}, +@code{INDEX} and @code{MOD} fields if they are present. White space is +used to separate the label, operation code and operand parts of the +instruction@footnote{In fact, Knuth's definition of MIXAL restricts the +column number at which each of these instruction parts must start. The +MIXAL assembler included in @sc{mdk}, @code{mixasm}, does not impose +such restriction.}. + +We have already listed the mnemonics associated will each MIX +instructions; sample MIXAL instructions representing MIX instructions +are: +@example +HERE LDA 2000 HERE represents the current location counter + LDX HERE,2(1:3) this is a comment + JMP 1234 +@end example + +@node MIXAL directives, Expressions, Basic structure, MIXAL +@comment node-name, next, previous, up +@subsection MIXAL directives + +MIXAL instructions can be either one of the MIX machine instructions +(@pxref{MIX instruction set}) or one of the following assembly +pseudoinstructions: + +@ftable @code +@item ORIG +Sets the value of the memory address to which following instructions +will be allocated after compilation. +@item EQU +Used to define a symbol's value, e.g. @w{@code{SYM EQU 2*200/3}}. +@item CON +The value of the given expression is copied directly into the current +memory address. +@item ALF +Takes as operand five characters, constituting the five bytes of a word +which is copied directly into the current memory address. +@item END +Marks the end of the program. Its operand gives the start address for +program execution. +@end ftable + +The operand of @code{ORIG}, @code{EQU}, @code{CON} and @code{END} can be +any expression evaluating to a constant MIX word, i.e., either a simple +MIXAL expression (composed of numbers, symbols and binary operators, +@pxref{Expressions}) or a w-expression (@pxref{W-expressions}). + +All MIXAL programs must contain an @code{END} directive, with a twofold +end: first, it marks the end of the assembler job, and, in the second +place, its (mandatory) operand indicates the start address for the +compiled program (that is, the address at which the virtual MIX machine +must begin fetching instructions after loading the program). It is also +very common (although not mandatory) to include at least an @code{ORIG} +directive to mark the initial value of the assembler's location counter +(remember that it stores the address associated with each compiled MIX +instruction). Thus, a minimal MIXAL program would be + +@example + ORIG 2000 set the initial compilation adress + NOP this instruction will be loaded at adress 2000 + HLT and this one at address 2001 + END 2000 end of program; execution will start at address 2000 +this line is not parsed by the assembler +@end example +@noindent +The assembler will generate two binary instructions (@code{NOP} (@w{+ 00 +00 00 00 00}) and @code{HLT} (+ 00 00 02 05)), which will be loaded at +addresses 2000 and 2001. Execution of the program will begin at address +2000. Every MIXAL program should also include a @code{HLT} instruction, +which will mark the end of program execution (but not of program +compilation). + +The @code{EQU} directive allows the definition of symbolic names for +specific values. For instance, we could rewrite the above program as +follows: + +@example +START EQU 2000 + ORIG START + NOP + HLT + END START +@end example +@noindent +which would give rise to the same compiled code. Symbolic constants (or +symbols, for short) can also be implicitly defined placing them in the +@code{LABEL} field of a MIXAL instruction: in this case, the assembler +assigns to the symbol the value of the location counter before compiling +the line. Hence, a third way of writing our trivial program is + +@example + ORIG 2000 +START NOP + HLT + END START +@end example + +The @code{CON} directive allows you to directly specify the contents of +the memory address pointed by the location counter. For instance, when +the assembler encounters the following code snippet + +@example + ORIG 1150 + CON -1823473 +@end example +@noindent +it will assign to the memory cell number 1150 the contents @w{- 00 06 61 +11 49} (which corresponds to the decimal value -1823473). + +Finally, the @code{ALF} directive let's you specify the memory contents +as a set of five (quoted) characters, which are translated by the +assembler to their byte values, conforming in that way the binary word +that is to be stored in the corresponding memory cell. This directive +comes in handy when you need to store printable messages in a memory +address, as in the following example: + +@example + OUT MSG MSG is not yet defined here (future reference) +MSG ALF "THIS " MSG gets defined here + ALF "IS A " + ALF "MESSA" + ALF "GE. " +@end example +@noindent +The above snippet also shows the use of a @dfn{future reference}, that +is, the usage of a symbol (@code{MSG} in the example) prior of its actual +definition. The MIXAL assembler is able to handle future references +subject to some limitations which are described in the following section +(@pxref{Expressions}). + +@cindex comments + +Any line starting with an asterisk is treated as a comment and ignored +by the assembler. + +@example +* This is a comment: this line is ignored. + * This line is an error: * must be in column 1. +@end example + +As noted in the previous section, comments can also be located after the +@code{MNEMONIC} field of an instruction, separated from it by white +space, as in + +@example +LABEL LDA 100 This is also a comment +@end example + +@node Expressions, W-expressions, MIXAL directives, MIXAL +@comment node-name, next, previous, up +@subsection Expressions +@cindex operator +@cindex binary operator +@cindex unary operator +The @code{ADDRESS}, @code{INDEX} and @code{MOD} fields of a MIXAL +instruction can be expressions, formed by numbers, identifiers and +binary operators (@code{+ - * / // :}). @code{+} and @code{-} can also +be used as unary operators. Order of evaluation is from left to right: +there is no other operator precedence rule, and parentheses cannot be +used for grouping. A stand-alone asterisk denotes the current memory +location; thus, for instance, + +@example + 4+2** +@end example + +@noindent +evaluates to 4 plus two times the current memory location. White space +is not allowed within expressions. + +The special binary operator @code{:} has the same meaning as in fspecs, +i.e., + +@example +A:B = 8*A + B +@end example +@noindent +while @code{A//B} stands for the quotient of the ten-byte number @w{@code{A} 00 +00 00 00 00} (that is, A right-padded with 5 null bytes or, what amounts +to the same, multiplied by 64 to the fifth power) divided by +@code{B}. Sample expressions are: + +@example +18-8*3 = 30 +14/3 = 4 +1+3:11 = 4:11 = 43 +1//64 = (01 00 00 00 00 00)/(00 00 00 01 00) = (01 00 00 00 00 00) +@end example +@noindent +Note that all MIXAL expressions evaluate to a MIX word (by definition). + +All symbols appearing within an expression must be previously defined. Future +references are only allowed when appearing stand-alone (or modified by +an unary operator) in the @code{ADDRESS} part of a MIXAL instruction, +e.g. + +@example +* OK: stand alone future reference + STA -S1(1:5) +* ERROR: future reference in expression + LDX 2-S1 +S1 LD1 2000 +@end example + +@node W-expressions, Local symbols, Expressions, MIXAL +@comment node-name, next, previous, up +@subsection W-expressions +@cindex w-expressions + +Besides expressions, as described above (@pxref{Expressions}), the MIXAL +assembler is able to handle the so called @dfn{w-expressions} as the +operands of the directives @code{ORIG}, @code{EQU}, @code{CON} and +@code{END} (@pxref{MIXAL directives}). The general form of a +w-expression is the following: + +@example + WEXP = EXP[(EXP)][,WEXP] +@end example +@noindent +where @code{EXP} stands for an expression and square brackets denote +optional items. Thus, a w-expression is made by a regular expression +followed by an optional expression between parenthesis, followed by any +number of similar constructs separated by commas. Sample w-expressions +are: + +@example +2000 +235(3) +S1+3(S2),3000 +S1,S2(3:5),23 +@end example + +W-expressions are evaluated as follows. First, all expressions are +evaluated according to the rules given in the previous section. Thus, if +we start with, say, @samp{S1+2(2:4)} where @samp{S1} equals 265230, we +have @samp{265232(2:4)}. The expression between parenthesis must be a +valid f-spec, for it specifies the bytes to be taken from the preceding +word. In our example, we must take 3 bytes of the word @w{@samp{+ 00 01 +00 48 16}} (which is 265232), and store them in positions 2, 3 and 4 of +the result, resulting in the new word @w{@samp{+ 00 00 48 16 00}} (i.e., +the decimal value 197632). When we have two expressions separated with a +comma, we take, for each one, the subfield specified and compose the +word to obtain the result. For instance, in the w-expression + +@example +1(1:2),66(4:5) +@end example +@noindent +we first take two bytes from 1 (00 and 01) and store them as bytes 1 and +2 of the result (obtaining @w{@samp{+ 00 01 00 00 00}}) and, afterwards, +take two bytes from 66 (01 and 02) and store them as bytes 4 and 5 of +the result, obtaining @w{@samp{+ 00 01 00 01 02}} (262210). The process +is repeated for each new comma-separated example. For instance: + +@example +1(1:1),2(2:2),3(3:3),4(4:4) = 01 02 03 04 00 +@end example + +As stated before, w-expressions can only appear as the operands of MIXAL +directives taking a constant value (@code{ORIG}, @code{EQU}, @code{CON} +and @code{END}). Future references are @emph{not} allowed within +w-expressions (i.e., all symbols appearing in a w-expression must be +defined before they are used). + +@node Local symbols, Literal constants, W-expressions, MIXAL +@comment node-name, next, previous, up +@subsection Local symbols +@cindex local symbols + +Besides user defined symbols, MIXAL programmers can use the so called +@dfn{local symbols}, which are symbols of the form @code{[1-9][HBF]}. A +local symbol @code{nB} refers to the address of the last previous +occurrence of @code{nH} as a label, while @code{nF} refers to the next +@code{nH} occurrence. Unlike user defined symbols, @code{nH} can appear +multiple times in the @code{LABEL} part of different MIXAL +instructions. The following code shows an instance of local symbols' +usage: + +@example +* line 1 +1H LDA 100 +* line 2: 1B refers to address of line 1, 3F refers to address of line 4 + STA 3F,2(1B//2) +* line 3: redefinition of 1H +1H STZ +* line 4: 1B refers to address of line 3 +3H JMP 1B +@end example + +Note that a @code{B} local symbol never refers to a definition in its +own line, that is, in the following program: + +@example + ORIG 1999 +ST NOP +3H EQU 69 +3H ENTA 3B local symbol 3B refers to 3H in previous line + HLT + END ST +@end example +@noindent +the contents of @samp{rA} is set to 69 and @emph{not} to 2001. An +specially tricky case occurs when using local symbols in conjunction +with @code{ORIG} pseudoinstructions. To wit@footnote{The author wants to +thank Philip E. King for pointing these two special cases of local +symbol usage to him.}, + +@example + ORIG 1999 +ST NOP +3H CON 10 + ENT1 * + LDA 3B +** rI1 is 2001, rA is 10. So far so good! +3H ORIG 3B+1000 +** at this point 3H equals 2003 +** and the location counter equals 3000. + ENT2 * + LDX 3B +** rI2 contains 3000, rX contains 2003. + HLT + END ST +@end example + +@node Literal constants, , Local symbols, MIXAL +@comment node-name, next, previous, up +@subsection Literal constants +@cindex literal constants + +MIXAL allows the introduction of @dfn{literal constants}, which are +automatically stored in memory addresses after the end of the program by +the assembler. Literal constants are denoted as @code{=wexp=}, where +@code{exp} is an w-expression (@pxref{W-expressions}). For instance, the +code + +@example +L EQU 10 + LDA =20-L= +@end example + +causes the assembler to add after the program's end an instruction with +contents 10, and to assemble the above code as the instruction @w{@code{ +LDA a}}, where @code{a} stands for the address in which the value 10 is +stored. In other words, the compiled code is equivalent to the +following: + +@example +L EQU 10 + LDA a +@dots{} +a CON 20-L + END start +@end example + diff --git a/doc/ss_devices.png b/doc/ss_devices.png Binary files differnew file mode 100644 index 0000000..bb2ee83 --- /dev/null +++ b/doc/ss_devices.png diff --git a/doc/ss_mix.png b/doc/ss_mix.png Binary files differnew file mode 100644 index 0000000..9d0e6b6 --- /dev/null +++ b/doc/ss_mix.png diff --git a/doc/ss_mix.txt b/doc/ss_mix.txt new file mode 100644 index 0000000..757026e --- /dev/null +++ b/doc/ss_mix.txt @@ -0,0 +1,31 @@ +|-----------------------------------------------------------| +| Menu | +|-----------------------------------------------------------| +| | +| | +| | +| | +| MIXVM / MIXAL / Devices | +| | +| | +| | +| | +| | +| | +|-----------------------------------------------------------| +| | +| Command output | +| | +| | +| | +|-----------------------------------------------------------| +| Command prompt | +|-----------------------------------------------------------| +| Status bar | +|-----------------------------------------------------------| + + + + + + diff --git a/doc/ss_mixal.png b/doc/ss_mixal.png Binary files differnew file mode 100644 index 0000000..506a170 --- /dev/null +++ b/doc/ss_mixal.png diff --git a/doc/ss_worddlg.png b/doc/ss_worddlg.png Binary files differnew file mode 100644 index 0000000..be6e7f2 --- /dev/null +++ b/doc/ss_worddlg.png |
