.

Chip8
Reference Manual

Peter Miller
pmiller@opensource.org.au
.

This document describes Chip8 version 1.1

and was prepared 18 September 2012.

This document describing the Chip8 program, and the Chip8 program itself, are
Copyright © 1990, 1991, 1998, 1999, 2012 Peter Miller

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 PARTICU-
LAR 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, see <http://www.gnu.org/licenses/>.

0
Read Me(Chip8) Read Me(Chip8)

NAME
chip8 − project change supervisor
Copyright © 1990, 1991, 1998, 1999, 2012 Peter Miller
Chip8 is distributed under the terms of the GNU General Public License. See the LICENSE section, below,
for more details.
DESCRIPTION
Chip8 was an interpreter used in a number of home computers based on RCA’s CDP1802 processor in the
late 1970’s. It implements a small machine designed specifically for simple video games. It has less than
40 instructions, including arithmetic, control flow, graphics, and sound.
This package includes an assembler for chip8, a disassembler, and an X client to run chip8 programs. This
distribution includes 33 games: 15puzzle, alien, ant, blinky, blitz, brix, car, connect4, field, guess, hidden,
hpiper, invaders, joust, kaleid, maze, merlin, missile, pong, puzzle, race, snake, spacefight, syzygy, tank,
tetris, tictac, uboat, ufo, vbrix, vers, wipeoff, worm3.
The assembler understood by this package differs from the assembler originaly documented for CHIP-8.
This is for a number of reasons... (a) the original was unpleasant to write a lexer for, (b) the opcodes were
not very orthogonal in appearance, (c) the format made arbitrary expression syntax have to tiptoe all around
it, (d) if I changed it I could re-use code from another of my assemblers.
ARCHIVE SITE
The latest version of Chip8 is available by HTTP from:
URL: http://chip8.sourceforge.net/
File: index.html # the Chip8 page
File: chip8−1.1.README # Description, from tar file
File: chip8−1.1.lsm # Description, in LSM format
File: chip8−1.1.spec # RedHat package specification
File: chip8−1.1.tar.gz # the complete source
This directory also contains a few other pieces of software written by me. Please have a look if you are
interested.
BUILDING
Instructions on how to build and test Chip8 are to be found in the BUILDING file included in this distribu-
tion.
LICENSE
Chip8 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.
Chip8 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, see
<http://www.gnu.org/licenses/>.
It should be in the LICENSE file included in this distribution.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

Reference Manual Chip8 1

Read Me(Chip8) Read Me(Chip8)

RELEASE NOTES
For excruciating detail, and also acknowledgments of those who generously sent me feedback, please see
the aux/CHANGES.* files included in this distribution.
A number of features have been added to Chip8 with this release. A few of them are detailed here:

Reference Manual Chip8 2

Build(Chip8) Build(Chip8)

NAME
chip8 − X11 Chip8 interpreter
Copyright © 1990, 1991, 1998, 1999, 2012 Peter Miller
The Chip8 package is distributed under the terms of the GNU General Public License. See the LICENSE
section, below, for more details.
SPACE REQUIREMENTS
You may need up to 4MB of disk space to unpack and build the Chip8 package. (This is the worst case
seen so far, most systems have binaries about 60% as big as this, 2MB is more typical.) Your mileage may
vary.
SITE CONFIGURATION
The Chip8 package is configured using the configure shell script included in this distribution.
The configure shell script attempts to guess correct values for various system-dependent variables used dur-
ing compilation, and creates the Makefile and common/config.h files. It also creates a shell script con-
fig.status that you can run in the future to recreate the current configuration.
Running Configure
Normally, you just cd to the directory containing Chip8’s source code and type
% ./configure
...lots of output...
%
If you’re using csh on an old version of System V, you might need to type
% sh configure
...lots of output...
%
instead to prevent csh from trying to execute configure itself.
Running configure takes a minute or two. While it is running, it prints some messages that tell what it is
doing. If you don’t want to see the messages, run configure with the quiet option; for example,
% ./configure −−quiet
%
By default, configure will arrange for the make install command to install the Chip8 package’s files in
/usr/local/bin, /usr/local/man and /usr/local/share/chip8. There are a number of options which allow you
to control the placement of these files.
−−prefix=PATH
This specifies the path prefix to be used in the installation. Defaults to /usr/local unless otherwise
specified.
−−exec−prefix=PATH
You can specify separate installation prefixes for architecture-specific files and architecture-inde-
pendent files. Defaults to ${prefix} unless otherwise specified.
−−bindir=PATH
This directory contains executable programs. On a network, this directory may be shared
between machines with identical hardware and operating systems; it may be mounted read-only.
Defaults to ${exec_prefix}/bin unless otherwise specified.
−−datadir=PATH
This directory contains installed data, such as the documentation, reports and shell scripts distrib-
uted with Chip8. On a network, this directory may be shared between all machines; it may be
mounted read-only. Defaults to ${prefix}/share/chip8 unless otherwise specified. A ‘‘chip8’’
directory will be appended if there is none in the specified path.
−−mandir=PATH
This directory contains the on-line manual entries. On a network, this directory may be shared
between all machines; it may be mounted read-only. Defaults to ${prefix}/man unless otherwise
specified.

Reference Manual Chip8 3

Build(Chip8) Build(Chip8)

configure ignores any other arguments that you give it.

On systems that require unusual options for compilation or linking that the Chip8 package’s configure
script does not know about, you can give configure initial values for variables by setting them in the envi-
ronment. In Bourne-compatible shells, you can do that on the command line like this:
$ CC=’gcc −traditional’ LIBS=−lposix ./configure
...lots of output...
$
Here are the make variables that you might want to override with environment variables when running con-
figure.
Variable: CC
C compiler program. The default is cc.
Variable: INSTALL
Program to use to install files. The default is install if you have it, cp otherwise.
Variable: LIBS
Libraries to link with, in the form −lfoo −lbar. The configure script will append to this, rather
than replace it.
If you need to do unusual things to compile the package, the author encourages you to figure out how con-
figure could check whether to do them, and mail diffs or instructions to the author so that they can be
included in the next release.
BUILDING CHIP8
All you should need to do is use the
% make
...lots of output...
%
command and wait. When this finishes you should see a directory called bin containing three files:
chip8as, chip8dis, and chip8run.
chip8as The chip8as program is an assembler for Chip8 programs.
chip8dis
The chip8dis program is a disassembler of Chip8 programs.
aereport The chip8run program is used run assembled Chip8 programs.
You can remove the program binaries and object files from the source directory by using the
% make clean
...lots of output...
%
command. To remove all of the above files, and also remove the Makefile and common/config.h and con-
fig.status files, use the
% make distclean
...lots of output...
%
command.
The file etc/configure.ac is used to create configure by a GNU program called autoconf . You only need to
know this if you want to regenerate configure using a newer version of autoconf .
TESTING CHIP8
The Chip8 package comes with a test suite. To run this test suite, use the command
% make sure
...lots of output...
Passed All Tests
%
The tests take less than a minute each, but they can vary greatly depending on your CPU.

Reference Manual Chip8 4

Build(Chip8) Build(Chip8)

INSTALLING CHIP8
As explained in the SITE CONFIGURATION section, above, the Chip8 package is installed under the
/usr/local tree by default. Use the −−prefix=PATH option to configure if you want some other path.
All that is required to install the Chip8 package is to use the
% make install
...lots of output...
%
command. Control of the directories used may be found in the first few lines of the Makefile file if you
want to bypass the configure script. You must also edit the other files generated by configure; it is usually
easier to re-run configure with the appropriate arguments.
The above procedure assumes that the soelim(1) command is somewhere in the command search PATH.
The soelim(1) command is available as part of the GNU Groff package, mentioned below in the PRINTED
MANUALS section. If you don’t have it, but you do have the cook package, then a link from roffpp to soe-
lim will also work.
PRINTED MANUALS
This distribution contains the sources to all of the documentation for Chip8, however the simplest way to
get the documentation is by anonymous FTP; a PostScript file of the Reference Manual is available from
the FTP sites listed in the README file. The Reference Manual contains the README and BUILDING
files, as well as all of the section 1 and section 5 manual pages.
GETTING HELP
If you need assistance with Chip8, please do not hesitate to contact the author at
Peter Miller <pmiller@opensource.org.au>
Any and all feedback is welcome.
When reporting problems, please include the version number given by the
% chip8run −version
Chip8 version 1.1.D094
...
%
command. Please run this command to get the exact number, do not send the text of this example.
Runtime Checking
In the common/main.h file, the is a define of DEBUG in comments. If the comments are removed, exten-
sive debugging is turned on. This causes some performance loss, but performs much run-time checking and
adds the −TRAce command line option.
When the −TRAce command line option is followed by one or more file names, it turns on execution traces
in those source files. It is usually best to place this on the end of the command line so that names of the
files to be traced are not confused with other file names or strings on the command line.
Problem Reports
If you send email to the author, please include the following information:
1. The type of UNIX
The author will need to know the brand and version of UNIX you are using, or if it is not UNIX
but something else. The output of "uname −sr" is usually sufficient (but not all systems have it).
2. The Version Number
In any information you send, please include the version number reported in the common/patch-
level.h file, or ‘chip8run −vers‘ if you can get it to compile.
3. The Archive Site
When and where you obtained this version of Chip8.
4. Unpacking
Did you have problems unpacking Chip8?

Reference Manual Chip8 5

Build(Chip8) Build(Chip8)

5. Building
Did you have problems building Chip8? This could have been the instructions included, it could
have been the configure script, it could have been the Makefile, or anything else.
6. Testing
Did you have problems with the tests? You could have had problems running them, or some of
them could have failed. If some tests fail but not others, please let me know which ones failed, and
include the fact that Chip8 was not set-uid-root at the time. The −k option to make can be useful
if some tests fail but not others.
7. Installation
Did you have problems installing Chip8? This could have been the instructions, or anything else.
At this point it would probably be a very good idea to print out the manual entries and read them carefully.
You will also want to print a copy of the Reference Manual; if you don’t gave GNU Groff, there should be a
PostScript copy at the archive site.
8. Using Chip8
Did you have problems using Chip8? This is a whole can of worms. If possible, include a shell
script similar to the tests which accompany Chip8, which reproduces the bug. Exit code 1 on fail-
ure (bug), exit code 0 on success (for when bug is fixed).
9. The Source Code
Did you read the code? Did you write some code? If you read the code and found problems, fixed
them, or extended Chip8, these contributions are most welcome.
The above list is inclusive, not exclusive. Any and all feedback is greatly appreciated, as is the effort and
interest required to produce it.
LICENSE
The Chip8 package 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.
The Chip8 package 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 PUR-
POSE. See the GNU General Public License for more details.
It should be in the LICENSE file included in this distribution.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

Reference Manual Chip8 6

chip8as(1) chip8as(1)

NAME
chip8as − assemble chip8 programs

SYNOPSIS
chip8as [ option... ] source-file binary-file
chip8as −Help
chip8as −VERSion
DESCRIPTION
The chip8as program is used to assemble chip8 programs for execution by the chip8run program.
OPTIONS
The following options are understood.
−Help This option may be used to provide information about how to use the chip8as program.
−VERSion
This option may be used to provide inforation about the version on the chip8as program being
executed.
−Listing listing-file
This option may be used to specify a listing file. By default, no listing is produced. The word −
may be used to indicate stdout.
−Hewlett_Packard_Header
This option may be used to cause chip8as to emit a Hewlett-Packard 48 calculator header to the
binary file. The default is to emit no header.
−Unix_Header
This option may be used to cause chip8as to emit a unix #! header to the binary file. he default is
to emit no header.
All options are case-insensitive. Abbreviations are indicated by the upper-case letters. Options and other
command line arguments may be aribtrarily mixed on the command line.
EXIT STATUS
The chip8as command will exit with a status of 1 on any error. The chip8as command will only exit with a
status of 0 if there are no errors.
SEE ALSO
chip8as(5)
The opcodes, as understood by the assmbler, and how they are interpreted by the interpreter.
chip8run(1)
The interpreter, to run the assembled byte code.
chip8run(5)
The file format, as output by the assembler and as understood by the interpreter.
chip8dis(1)
A disassembler, so that you can turn assembled byte code into something more readable.
COPYRIGHT
chip8as version 1.1
Copyright (C) 1990, 1991, 1998, 1999, 2012 Peter Miller
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.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

7
chip8dis(1) chip8dis(1)

NAME
chip8dis − disassemble chip8 programs

SYNOPSIS
chip8dis [ option... ] binary-file assembler-file
chip8dis −Help
chip8dis −VERSion
DESCRIPTION
The chip8dis program is used to disassemble chip8 programs.
OPTIONS
The following options are understood.
−Help This option may be used to provide information about how to use the chip8dis program.
−VERSion
This option may be used to provide inforation about the version on the chip8dis program being
executed.
All options are case-insensitive. Abbreviations are indicated by the upper-case letters. Options and other
command line arguments may be aribtrarily mixed on the command line.
EXIT STATUS
The chip8dis command will exit with a status of 1 on any error. The chip8dis command will only exit with
a status of 0 if there are no errors.
SEE ALSO
chip8as(1)
An assembler, for assembling chip8 programs into the byte-code to be interpreted.
chip8as(5)
The opcodes, as understood by the assmbler, and how they are interpreted by the interpreter.
chip8run(1)
The interpreter, to run the assembled byte code.
chip8run(5)
The file format, as output by the assembler and as understood by the interpreter.
COPYRIGHT
chip8dis version 1.1
Copyright (C) 1990, 1991, 1998, 1999, 2012 Peter Miller
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.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

8
GPL(GNU) Free Software Foundation GPL(GNU)

GNU GENERAL PUBLIC LICENSE

Version 2, June 1991

Copyright (C) 1989, 1991 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is
not allowed.
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.

GNU GPL 9
GPL(GNU) Free Software Foundation GPL(GNU)

GNU GENERAL PUBLIC LICENSE

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. 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.
1. 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.
2. 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:
a) You must cause the modified files to carry prominent notices stating that you changed the files and the
date of any change.
b) 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.
c) 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.)
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.

GNU GPL 10
GPL(GNU) Free Software Foundation GPL(GNU)

3. 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:
a) 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,
b) 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,
c) 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.)
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.
4. 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.
5. 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.
6. 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.
7. 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

GNU GPL 11
GPL(GNU) Free Software Foundation GPL(GNU)

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.
8. 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.
9. 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.
10. 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.
NO WARRANTY
11. 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.
12. 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 OF TERMS AND CONDITIONS

GNU GPL 12
GPL(GNU) Free Software Foundation GPL(GNU)

Appendix: 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.
one line to give the program’s name and a brief idea of what it does.
Copyright (C) 19yy 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,
see <http://www.gnu.org/licenses/>.
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:
Gnomovision version 69, Copyright (C) 19yy 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.
The hypothetical commands ‘show w’ and ‘show c’ should show the appropriate parts of the General Public
License. Of course, the commands you use may be called something other than ‘show w’ and ‘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:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program ‘Gnomovision’ (which makes
passes at compilers) written by James Hacker.
signature of Ty Coon, 1 April 1989
Ty Coon, President of Vice
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.

GNU GPL 13
chip8run(1) chip8run(1)

NAME
chip8run − run a chip8 program

SYNOPSIS
chip8run [ option... ] game
chip8run [ option... ] −File binary-file
chip8run −Help
chip8run −VERSion
DESCRIPTION
The chip8run program is used to run chip8 programs. It is an X11 client.
The first form, where only the name of a game is given, constructs a filename of the form
/usr/local/lib/chip8/game.chp and attempts to open it.
The second form may be used to open a specific file.
A great variety of file formats are understood, including some of the HP48 formats, and also the UNIX
executable #! convention.
OPTIONS
The following options are understood.
−Help This option may be used to provide information about how to use the chip8run program.
−VERSion
This option may be used to provide inforation about the version on the chip8run program being
executed.
−BackGround color
This option may be used to set the backgound of the chip8run window to the color specified.
−BorDer_color color
This option may be used to set the border color of the chip8run window to the color specified.
−Border_Width number
This option may be used to set the border width of the chip8run window to the width specified.
−DEbug
This option may be used to turn on debugging mode. Additional information is displayed as to
the chip8 machine’s internal state. Addition buttons are provided for additional control.
−Display display-name
This option may be used to set which X display to use. The default is the $DISPLAY
environment variable, or :0 if not set.
−FoNt font-name
This option may be used to set the font to be used in the chip8run window.
−ForeGround color
This option may be used to set the foregound of the chip8run window to the color specified.
−Geometry geometry-spec
This option may be used to specifiy the initial position and/or size of the chip8run window.
−IConic This option may be used to specify that the chip8run window should initially be iconic. You
need a cooperative window managaer.
−Icon_Geometry geometry-spec
This option may be used to specify the position and/or size of the chip8run window’s icon.
−Name string
This option may be used to set the name the chip8run window is referred to as.

14
chip8run(1) chip8run(1)

−Test_Mode
This option may be used to test the chip8 machine. It makes the "Quit" button generate and exit
code of 1, rather than 0 (it is an error if the user quits out of a test). It makes screen placement
forced. Run-time errors result in exit 1, rather than turning on debugging.
−Title string
This option may be used to set the name the chip8run window is referred to as.
−XRM string
This option may be used to specify an X resource.
All options are case-insensitive. Abbreviations are indicated by the upper-case letters. Options and other
command line arguments may be aribtrarily mixed on the command line.
EXIT STATUS
The chip8run command will exit with a status of 1 on any error. The chip8run command will only exit
with a status of 0 if there are no errors.
FILES
/usr/local/lib/chip8
This directory is where games are installed. A number of games are included in this distribution.
SEE ALSO
chip8as(1)
An assembler, for assembling chip8 programs into the byte-code to be interpreted.
chip8as(5)
The opcodes, as understood by the assmbler, and how they are interpreted by the interpreter.
chip8run(5)
The file format, as output by the assembler and as understood by the interpreter.
chip8dis(1)
A disassembler, so that you can turn assembled byte code into something more readable.
COPYRIGHT
chip8run version 1.1
Copyright (C) 1990, 1991, 1998, 1999, 2012 Peter Miller
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.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

15
chip8as(5) chip8as(5)

NAME
chip8as − chip8 opcodes

DESCRIPTION
This file documents the input format of the chip8as program. As a side-effect, it also documents the
various opcodes the chip8run program understands. Input files are text files.
MACHINE
This section describes the chip8 machine.
Address Space
The chip8 machine has an address space from 0x000 to 0xFFF. This address space contains both
code and data. Addresses 0x000 to 0x1FF are reserved. Some implementations place the
interpreter here. When the chip8 machine is reset, the PC is set to 0x200, thus chip8 programs
start at 0x200.
Opcodes
Opcodes are all 16 bits long. Opcodes must be aligned on even-byte boundaries (some
implementations do not require this). Opcodes are stored big-endian, high byte first then low
byte.
Registers
The chip8 machine has a number of registers.
v0 to v15
These are general 8-bit unsigned arithmetic registers. Regsiters v10 to v15 may also be
referred to as vA to vF. Arithmetic is done in 2s compliment.
v15 In addition to being a general register, this register may sometimes be used as an
exception indicator by some opcodes.
time The time register is a count-down timer. It is decrimented by 1 every 60th of a second
until it reaches 0.
tone The time register is a count-down timer. It is decrimented by 1 every 60th of a second
until it reaches 0. If the register is not 0, a beeper will be beeping. (Some
implementations make the beeping optional.)
i This register is a pointer register. It is 16-bits long, although the address space is only
12-bits. It is an error to attempt to reference memory above 0xFFF.
. The dot register may be used to refer to the value of the program counter maintained by
the assembler. It refers to the value of the program counter before the opcode is
generated.
key This isn’t really a register, even though the opcode treat it that way. There are 16 keys
available, labeled "0" − "F". Keys may be sampled or waited for.
Display
The chip8 machine has a 64×32 display. It is 64 pixels wide and 32 pixels high. Row 0 is the top
of the screen, row 31 is the bottom of the screen. Column 0 is the left of the screen, column 63 is
rhe right of the screen. You may assume pixels are square. (See the high and low opcodes; there
is also a high resolution 128×64 display mode.)
EMULATOR DIFFERENCES
There are a number of differences between the various emulators. No doubt this could all be resolved if
anyone had the sources to the original (circa 1977) interpreter.
Add Aligned Opcodes
Some emulators accept opcodes at odd addresses, and some don’t. Defensive programming
should use even-aligned opcodes. (This distribution demands even-aligned opcodes on
emulation, and gives a fatal error for odd-aligned opcodes on assembly, but accepts odd-aligned

16
chip8as(5) chip8as(5)

opcodes for disassembly.)

The I Register
The value of the I register after save and restore opcodes is not well defined. Some emulator
leaves the I register pointing past the last location referenced, other emulators leave it pointing at
the first location referenced. Defensive programming should assume the I register is not
meaningful after these opcodes. (This distribution is consistent with Gustafsson’s emulator,
which moves the I register past the last location referenced.)
The Borrow Flag
Many emulators calculate the borrow after the sub and dif opcodes incorrectly. Defensive
programming should assume the v15 register is not meaningful after these opcodes. (This
distribution is consistent with Gustafsson’s emulator, which performs the operation in more than
8 bits, and sets the v15 register to 1 if any of the high bits of the result are non-zero, otherwise
sets it to 0)
LINE FORMAT
The input of the chip8as program is oriented around lines. Each line, in general, has the form
[ label: ] opcode [ expr, ... ]
The label definition on the start of the line is optional, opcodes take zero or more expressions. End-of-line
is significant, except after commas. It is also legal to have blank lines, or lines consisting of only a label
definition. Forward references of labels are legal, as it is a 2-pass assembler.
TOKENS
This section details how the text file is broken into tokens.
White Space
White space consists of tabs and spaces. White space is ignored, except where it serves to
separate tokens. Comments commence with semicolon (’;’) and end at end-of-line (’\n’);
comments are logical white space.
Identifiers
Identifiers start with an alphabetic character or and underscore (’_’) or dot (’.’); followed by zero
or more alphabetic, numeric, underscore or dot characters. Identifiers are case-sensitive unless
they are opcode names or register names. Identifiers may be of any length, and all characters are
significant.
Numbers
The default radix is decimal. An "0x" prefix will yeild hexadecimal numbers, a "0" prefix will
yield octal numbers.
OPCODES
The chip8 machine opcodes are described here.
scdown n
Scroll the screen down n pixels. [Super-Chip]
This opcode delays until the start of a 60Hz clock cycle before drawing in low resolution mode.
(Use the delay timer to pace your games in high resolution mode.)
Code generated: 0x00Cn
clear
Clear the display.
Code generated: 0x00E0
ret
Return from subroutine. See also: the "call" opcode. It is an error if there is no subroutine to
return from.
Code generated: 0x00EE

17
chip8as(5) chip8as(5)

compatibility
Mangle the ‘‘save’’ and ‘‘restore’’ opcodes to leave the I register unchanged.
Warning: This opcode is not a standard Chip 8 opcode. It is provided soley to allow testing and
porting of Chip 8 games which rely on this behaviour.
Code generated: 0x00FA
scright
Scroll the screen right 4 pixels. [Super-Chip]
This opcode delays until the start of a 60Hz clock cycle before drawing in low resolution mode.
(Use the delay timer to pace your games in high resolution mode.)
Code generated: 0x00FB
scleft
Scroll the screen left 4 pixels. [Super-Chip]
This opcode delays until the start of a 60Hz clock cycle before drawing in low resolution mode.
(Use the delay timer to pace your games in high resolution mode.)
Code generated: 0x00FC
low
Low resolution (64×32) graphics mode (this is the default). [Super-Chip]
Code generated: 0x00FE
high
High resolution (128×64) graphics mode. [Super-Chip]
Code generated: 0x00FF
jump addr
Jump to addr. The addr must be even. The addr must be in the range 0x200 to 0xFFE. The
addr expression must be relative to some label.
Code generated: 0x0NNN, where NNN is the low 12 bits of addr.
jump addr, v0
Jump to addr + v0. The addr must be even. The addr must be in the range 0x200 to 0xFFE. The
addr expression must be relative to some label. It is a run-time error if the value of register v0 is
odd. It is a run-time error if addr+v0 is not in the range 0x2000 to 0xFFE.
Code generated: 0xBNNN, where NNN is the low 12 bits of addr.
call addr
Call subroutine at addr. The addr must be even. The addr must be in the range 0x200 to 0xFFE.
The addr expression must be relative to a label. It is a run-time error if there are too many
subroutine calls, although you may safely assume at least 32 levels.
Code generated: 0x1NNN, where NNN is the low 12 bits of addr.
skip.eq vX, value
Skip the next instruction if the value of register vX is equal to value. The value must be in the
range −128 to 255.
Code generated: 0x3XYY, where YY is the low 8 bits of value.
skip.eq vX, vY
Skip the next instruction if the value of register vX is equal to the value of register vY.
Code generated: 0x3XY0
skip.eq vX, key
Skip the next instruction if they key with the same number as the low 4 bits of the value of
register vX is currently being pressed.
Code Generated: 0xEX9E
skip.ne vX, value
Skip the next instruction if the value of register vX is not equal to value. The value must be in the
range −128 to 255.
Code generated: 0x4XKK, where KK is the low 8 bits of value.

18
chip8as(5) chip8as(5)

skip.ne vX, vY
Skip the next instruction if the value of register vX is not equal to the value of register vY.
Code generated: 0x9XY0
skip.ne vX, key
Skip the next instruction if the key with the same number as the the low 4 bits of the value of
register vX currently not being pressed.
Code generated: 0xEXA1
load vX, value
Load register vX with the value. The value must be in the range −128 to 255.
Code generated: 0x6XKK, where KK is the low 8 bits of value.
load vX, key
If no key is currently being pressed, block until one is. Load register vX with lowest number of
all keys currently being pressed. The beeper will sound while any key is being pressed. Block
until the key is released (implementations need not block if they guarantee that the key will not be
"seen" by any of the key opcodes until it is released and pressed again).
Code generated: 0xFX0A
load vX, vY
Load register vX with the value of register vY. Some implementations may alter the value of
register v15 (to what?).
Code generated: 0x8XY0
load vX, time
Load register vX with the value of the time register.
Code generated: 0xFX07
load time, vX
Load the time register with the value of register vX.
Code generated: 0xFX15
load tone, vX
Load the tone register with the value of register vX.
Code generated: 0xFX18
load i, addr
Load register i with the addr. The addr must be in the range 0x200 to 0xFFF.
Code generated: 0xANNN, where NNN is the low 12 bits of addr.
add vX, value
Add value to register vX. The value must be in the rabge −128 to 255.
Code generated: 0x7XKK, where KK is the low 8 bits of value.
add vX, vY
Add the value of register vY to register vX. The register v15 is set to 1 if the result overflows,
otherwise 0.
Code generated: 0x8XY4
add i, vX
Add the value of register vX to register i.
Code generated: 0xFX1E
or i, vX
Bitwise OR the value of register vY into register vX. Some implementations may change the
value of register v15 (to what?).
Code generated: 0x8XY1
and vX, v
Bitwise AND the value of register vY into register vX. Some implementations may change the
value of register v15 (to what?).

19
chip8as(5) chip8as(5)

Code generated: 0x8XY2

xor vX, vY
Bitwise XOR the value of register vY into register vX. Some implementations may change the
value of register v15 (to what?).
Code generated: 0x8XY3
sub vX, vY
Subtract the value of register vY from register vX. Register v15 is set to 1 is the result would be
less than zero, 0 otherwise.
Code generated: 0x8XY5
shr vX
Shift the value of register vX right one bit. Register v15 is set to 1 if vX was odd before the
operation, 0 otherwise.
Code generated: 0x8X06
dif vX, vY
Set register vX to the value of register vY minus the value of register vX. Register v15 is set to 1
is the result would be less than zero, 0 otherwise.
Code generated: 0x8XY7
shl vX
Shift the value of register vX left one bit. Register v15 is set to 1 if the high bit of register vX was
set before the operation, 0 otherwise.
Code generated: 0x8X0E
rnd vX, value
Register vX is set to the bitwise AND of a pseudo-random number and the value. The value must
be in the range 0 to 255.
Code generated: 0xCXKK, where KK is the low 8 bits of value.
draw vX, vY, rows
This opcode is used to draw an image on the screen. The image will be 8 pixels wide and rows
pixels long. The image will be displayed at (x,y) coordinates, where x is the value of register vX
bitwise-AND 0x3F, and y is the value of register vY bitwise-AND 0x1F. If any of the image
would be drawn outside the screen area, it is clipped (it does not wrap around).
The origin (0,0) is the top-left corner of the screen. The image to be drawn is pointed to by the i
register. The most-significant bit is on the left.
Drawing is done by using XOR. If this causes one or more pixels to be erased, v15 is set to 1,
otherwise v15 is set to 0.
The rows must be in the range 1 to 15. It is a run-time error if the value of register i causes non-
existent memory to be accessed.
This opcode delays until the start of a 60Hz clock cycle before drawing in low resolution mode.
(Use the delay timer to pace your games in high resolution mode.)
Code generated: 0xDXYN, where N is the low 4 bits of rows.
xdraw vX, vY, rows
As above, however the image is always 16×16 pixels. [Super-Chip]
Code generated: 0xDXY0
hex vX
Point I to an image of a hex character for the low 4 bits of the value of register vX. The image is
4 pixels wide and 5 pixels high.
Code generated: 0xFX29
bcd vX
Store a BCD representation of the value of register vX into the three bytes pointer to be register i,
most significant digit first. It is a run-time error if the value of register i causes non-existent
memory to be accessed.

20
chip8as(5) chip8as(5)

Code generated: 0xFX33

save vX
Store the values of registers v0 to vX into the bytes pointed to by register i, incrimenting register i
past them. It is a run-time error if the value of register i causes non-existent memory to be
accessed.
Code generated: 0xFX55
restore vX
Read the values of registers v0 to vX from the bytes pointed to by register i, incrimenting register
i past them. It is a run-time error if the value of register i causes non-existent memory to be
accessed.
Code generated: 0xFX65
flags.save vX
Store the values of registers v0 to vX into the ‘‘flags’’ registers (this means something in the
HP48 implementation). (X < 8) [Super-Chip]
Code generated: 0xFX75
flags.restore vX
Read the values of registers v0 to vX from the ‘‘flags’’ registers (this means something in the
HP48 implementation). (X < 8) [Super-Chip]
Code generated: 0xFX85
exit
This opcode is used to terminate the chip8run program. It causes the chip8run program to exit
with a successful exit status. [Super-Chip]
Code generated: 0x00FD.
exit value
This opcode is used for testing the chip8run program, and are not normal chip8 opcodes. They
cause the chip8run program to exit with the given exit status. This is primarily of use in
performing regression tests of the chip8 machine implementation. The value must be in the range
0 to 1.
Exit status 0 indicates a successful result, exit status 1 indicates an error result.
Code generated: 0x001X, where X is the low 4 bits of value.
PSEUDO-OPS
The following are pseudo-ops of the chip8as program.
.ascii expr, ...
Each expression is emitted into the code stream as the bytes composing the given strings. This is
usually used to embed copyright notices into programs. There is no built-in ascii font available
for drawing.
.byte expr, ...
Each expression is emitted into the code stream as a byte. The exprs must be in the range −128 to
255.
.word expr, ...
Each expression is emitted into the code stream as a word, high byte then low byte. It is an error
if . is odd. The exprs must be in the range −32768 to 32767.
.align [ expr ]
This pseudo-op may be used to align . with various boundaries. The default is a word boundary
(2 byte). Alignment boundaries must be powers of 2. Zero or more zero-valued bytes are emitted
into the code stream to achieve alignment.
.ds expr [ , expr ]
This pseudo-op may be used to define storage space in the code stream. The first argument is the
number of bytes to use, the second argument is the value to store there (defaults to zero).

21
chip8as(5) chip8as(5)

label .equ expr

This pseudo-op may be used to set a label to a calculated expression.
.pic expr, ...
This pseudo-op may be used to construct a picture for future drawing by a series of draw
opcodes. It breaks the image up into a series of vertical slices 8 pixels wide.
All of the expressions must be strings, blank characters will be 0s in the output, all other
characters will be 1s. It does not understand tabs. All the strings must be of the same length.
See the snake example program distributed with chip8 for a number of examples of this pseudo-
op.
.title word, word
This pseudo-op may be used to set the page title on the listing. The title has two lines. The first
argument is the first line of the title, and the second argument is the second line.
.xpic expr, ...
This pseudo-op may be used to construct a picture for drawing by a series of xdraw opcodes. It
breaks the image up into a series of vertical slices 16 pixels wide. Because the xdraw opcode
requires a 16 line high image, the given picture will be padded to a multiple of 16 lines, if
necessary.
.xref on
This pseudo-op may be used to cause a cross reference to be added to the listing.
All of the expressions must be strings, blank characters will be 0s in the output, all other
characters will be 1s. It does not understand tabs. All the strings must be of the same length.
CONDITIONAL ASSEMBLY
It is possible to conditionally assemble different portions of code. Conditionals may be nested arbitrarily
deeply. This is controlled by the following directives:
define name
This directive is used to define a conditionl name. The conditions are based on the existence or
absence of these lines.
ifdef name
Begin a conditionl portion of code, including the bracketed lines if the name was previously
defined by a define directive.
ifndef name
Begin a conditionl portion of code, including the bracketed lins if the name was not previously
defined by a define directive.
else Reverse the sense of a conditional compilation. (This is optional.)
endif End the bracketing of source lines performed by a conditional.
SEE ALSO
chip8as(1)
An assembler, for assembling chip8 programs into the byte-code to be interpreted.
chip8as(5)
The opcodes, as understood by the assmbler, and how they are interpreted by the interpreter.
chip8run(1)
The interpreter, to run the assembled byte code.
chip8run(5)
The file format, as output by the assembler and as understood by the interpreter.
chip8dis(1)
A disassembler, so that you can turn assembled byte code into something more readable.

22
chip8as(5) chip8as(5)

COPYRIGHT
chip8 version 1.1
Copyright (C) 1990, 1991, 1998, 1999, 2012 Peter Miller
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.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

23
chip8run(5) chip8run(5)

NAME
chip8 file formats

DESCRIPTION
The chip8run program understands 3 file formats: raw, HP and #!. The only difference is the headers. All
3 formats have a header, followed by data. The data will be at most 3584 bytes long.
RAW FORMAT
The raw format has no header. There is only the data section in the file.
HP FORMAT
the HP format has a 13 byte header in the format
8-bytes magic number "HPHP48-A"
48,50,48,50,34,38 (hex)
2.5-bytes type
0x02C2A for "string"
2.5-bytes length
in nybbles, including length.
The 2.5 byte fields are encodes as big-endian nybbles.
UNIX FORMAT
The #! format discards all bytes upto the first newline (’\n’) character, this is useful to make chip8 programs
self-executing, by making the first line
#! /usr/local/bin/chip8run −
Which tells unix to invoke the chip8run(1) program and feed it the executing file on its standard input.
SEE ALSO
chip8as(1)
An assembler, for assembling chip8 programs into the byte-code to be interpreted.
chip8as(5)
The opcodes, as understood by the assmbler, and how they are interpreted by the interpreter.
chip8run(1)
The interpreter, to run the assembled byte code.
chip8dis(1)
A disassembler, so that you can turn assembled byte code into something more readable.
COPYRIGHT
chip8 version 1.1
Copyright (C) 1990, 1991, 1998, 1999, 2012 Peter Miller
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.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

24
15puzzle(7) 15puzzle(7)

NAME
15puzzle − X11 Chip8 game

SYNOPSIS
chip8run 15puzzle
DESCRIPTION
Here is the infamous 15 puzzle for Chip8. The puzzle, as you doubtless recall, has 15 squares numbered 1
through 15 (in this case, 1 through F) and one hole. You can move the hole about and must put the pieces
in order.
When you first run puzzle, it comes up solved. Thereafter, pressing IRestart causes the puzzle to have 32
random moves made, effectively randomizing the puzzle. If 32’s not enough for you, just press IRestart
again.
The program does not check to see if you’ve solved the puzzle, and therefore nothing special happens when
you do except for the warm, fuzzy feeling that you have beaten it.
The Display

The Keys
You enter moves by using the keys. The key’s
1 2 3 C position in that 4×4 matrix corresponds to the square
in that position of the puzzle matrix. Pushing a key
4 5 6 D causes the hole to migrate to that position. The
migration is performed in the order up, down, left,
7 8 9 E right; it is not necessary to limit your moves to those
rows and columns containing the hole; you can
A 0 B F request that the hole move to any position.

COPYRIGHT
15 Puzzle version 1.0
Author Unknown
AUTHOR
Author Unknown

Reference Manual Chip8 25

Alien(7) Alien(7)

NAME
Alien − Shoot the alien invaders

SYNOPSIS
chip8run alien
DESCRIPTION
None.
The Display

They Keys

1 2 3 C 3: Left
C: Right
4 5 6 D
A: Fire
7 8 9 E

A 0 B F

Copyright
Jonas Lindstedt
Author
Jonas Lindstedt

Reference Manual Chip8 26

ant(7) ant(7)

NAME
ant − In search of Coke

SYNOPSIS
chip8run ant
DESCRIPTION
Rumours through the grape vine of the local ant community indicate that there is a partially empty Coke
can in Zoom’s room. So far many brave ants have gone in search of the mystic can, yet none have returned.
They are feared to be dead. It is your mission as Bink to find a safe path to the Coke can so that others may
follow. Beware, however, for Zoom has set many treacherous obsticles to block you and booby traps to zap
you. Bink has only his cool nerves and jumping ability (the only jumping ant in the world) to help him on
this journey.
Pressing the jump key and the right key simultaneously will help clearing large obsticles. Actually, press
the jump key slightly ahead of the right key.
Being of little mass, Bink can stop on a dime and change course in mid-air at will.
This game has no randomization. Learn the terrain.
I take full credit for the design and development of Ant. The game theme is original as far as I know.
There are many tricks to getting around Ant. Be aware of spoilers when posting to the net.
The Display

The Keys

1 2 3 C 3: Left
C: Right
4 5 6 D
A: Jump
7 8 9 E

A 0 B F

COPYRIGHT
Ant version 1.0
Copyright (C) 1991 Erin S Catto
I take no blame for worn calculator keys.
AUTHOR
Erin S Catto <catto@ecn.purdue.edu>

Reference Manual Chip8 27

Blinky(7) Blinky(7)

NAME
Blinky − PacMan clone

SYNOPSIS
chip8run blinky
DESCRIPTION
Blinky is a PacMan game for the Chip8.
As Blinky, you are chased around in an office environment by two bosses, Packlett and Heward. Packlett
does management by walking around, but Heward believes in the American dream, and possesses quite a
killer instinct. Anyway, don’t let them get to you, unless you are feeling very aspirant. This, of course,
requires the recent fulfilment of one of four major contracts, found near the corners of the building.
Otherwise, the office is filled with small tasks, just waiting for your attention. If you manage to take care of
them all, your intray will overflow, just over weekend. This is the curse of any responsible and hard
working employee. However, neither boss know of the emergency exit which leads from one part of the
office to the other, so this may be one way to avoid them, if everything else fails. As in most decent
companies, you are given a chance to clear up the mess of your first blunder. The second time on the rug...
off you go. There is a small comfort in that the recommendation reflects how well you did.
Recommendation points are awarded as follows:
0 points Make use of the emergency exit
1 point Take care of a minor task
4 points Negotiate a major contract
25 points Show Heward a recently fulfiled contract
50 points Show Packlett a recently fulfiled contract
100 points Clear the office environment from tasks

The Display

The Keys
Blinky control keys are:

1 2 3 C 1: reset
3: up
6: down
4 5 6 D
7: left
8: right
7 8 9 E

A 0 B F

Reference Manual Chip8 28

Blinky(7) Blinky(7)

COPYRIGHT
Blinky version 2.0
Copyright (C) 1990 Christian Egeberg
Noncommercial distribution allowed, provided that copyright messages are preserved, and any modified
versions are clearly marked as such.
This software is provided "as is" and without any express or implied warranties, including, but not limited
to, the implied warranties of merchantability and fitness for a particular purpose.
AUTHOR
Christian Egeberg <egeberg@solan.unit.no>

Reference Manual Chip8 29

Blitz(7) Blitz(7)

NAME
Blitz − bomb the bad guys

SYNOPSIS
chip8run blitz
DESCRIPTION
This game is a BOMBER clone. You are in a plane, and you must destroy the towers of a town. Your
plane is flying left to right, and goes down. The game ends when you crash yourself on a tower...
This Display

The Keys

1 2 3 C 5: Drop bomb

4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Blitz version 1.0
Copyright (C) David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 30

Brix(7) Brix(7)

NAME
Brix − Knock out the bricks

SYNOPSIS
chi8run brix
DESCRIPTION
This is a version of the classic game of knock out the bricks. Not particularly exciting, but I had to include
something to show how the interpreter is used.
Once you get all of the bricks, the game will freeze. Use the restart button to start the game again.
The Display

The dots at the top-left indicate the number of balls you have remaining.
The number at the top-right is the number of bricks you have hit so far. You are aiming for a total of 96.
The short line at the bollom of the screen is the paddle. The ball will bounce off the top, the sideas and the
paddle. If it touches the bottom of the screen, you lose a ball.
The Keys

1 2 3 C 4: move paddle left

6: move paddle right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Brix version 1.0
Copyright (C) 1990 Andreas Gustafsson
Noncommercial distribution allowed, provided that this copyright message is preserved, and any modified
versions are clearly marked as such.
THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
AUTHOR
Andreas Gustafsson <gson@niksula.hut.fi>

Reference Manual Chip8 31

Car(7) Car(7)

NAME
Car − driving game

SYNOPSIS
chip8run car
DESCRIPTION
This game simulates a racing car.
The other cars are a big dumb, though. They seem to have all stalled.
The Display

The Keys

1 2 3 C 7: left
8: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Car version
Copyright (C) 1994 K. v. Sengbusch
AUTHOR
K. v. Sengbusch

Reference Manual Chip8 32

Connect4(7) Connect4(7)

NAME
Connect4 − two player join the dots

SYNOPSIS
chip8run connect4
DESCRIPTION
This game is for two players. The goal is to align 4 coins in the game area. Each player’s coins are
colored. When you drop a coin, it is paced on the latest dropped coin in the same column, or at the bottom
if the column is empty. Once the column is full, you cannot place any more coins in it. To select a column,
use 4 and 6. To drop a coin, use 5. There is no winner detection yet. This will be soon avalaible (Hey! I
don’t spend my life on CHIP8 !).
The Display

The Keys

1 2 3 C 4: left
5: place piece
6: right
4 5 6 D

7 8 9 E

A 0 B F

Placement of pieces alternate.

Points
1 point per egg touched
8 points for clearing bonus round
1 player for clearing bonus round
COPYRIGHT
Connect4 version 1.0
Copyright (C) David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 33

Field(7) Field(7)

NAME
Field − mavigate the asteroid field

SYNOPSIS
chip8run field
DESCRIPTION
A title screen will appear proclaiming the game name (and my name) with quite a bit of animation. The
amount of title screen animation explains for its rather large size for a S-CHIP game of 700 some odd
bytes. However, it is still amazing to me that a game as simple as this can be written in so few bytes!

To play press the ‘‘0’’ key during the title sequence, you may have to hold it down for a second or to (since
I don’t check keypresses between every single frame of animation.)
The screen will then appear like:
_________________________
|# #|
| | .−−−−ASTEROIDS
|# | |
| #<−−−’
| |
|#_______________________#|
The keys are now defined as:
1 − Apply thrust to the left ( so you move right! ) 2 − Apply thrust to the right ( so you move left! ) / −
Move up * − Move Down 7 − Abandon Game and return to the Title Screen
Now once the game is going.(you must apply thrust to actually start.) The screen appears like this.
_________________________ |# # #| | +− # | |# ˆ # || # | #
#| | | # | |#____|__________________#|
|
You

Now your on your own... Just don’t hit anything.

Your score is based on how long you last, actually it is more of a rating than a score, and it is revealed to
you by the OWL on the Title screen. The score is 0−F (in hex because that was easier to do, and since this
is my first chip program, I think you can be happy with that, anyway it will probably only be by an act of
God that you make it very far.)
Hope you enjoy!
Let me know if you like it, or if there are any bugs, or you want more. I would greatly appreciate hearing
from any of you HP48sx whizes. This horizontal scrolling looks tremendously like DEFENDER and
perhaps that is where this program will go!.

Reference Manual Chip8 34

Field(7) Field(7)

The Display
The Keys

1 2 3 C 7: left
8: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Field version 1.0
Copyright (C) 1991 Al Roland

Oh yeah... I release this as FREEWARE, play it, and enjoy it. But don’t modify, mutilate, or spindle this
program unless I know about (and approve) it.
AUTHOR
Al Roland <droland@eng.auburn.edu>

711 Cary Drive

Auburn, Al 36830
I, Al Roland, being of sound body and mind, and poor grammatical and spelling ability, make no warranties
expressed or implied to anyone no matter how unsound their body and mind are regarding the included
software, and the damages that might result to those unsound bodies and minds, when they misuse this
software on their calculator. I also will not be held responsible for a grade drop when you play this game in
class and forget to take notes. And, blah blah blah....

Reference Manual Chip8 35

Guess(7) Guess(7)

NAME
Guess − guess the number

SYNOPSIS
chip8run guess
DESCRIPTION
Think to a number between 1 and 63. CHIP8 shows you several boards and you have to tell if you see your
number in them. Press 5 if so, or another key if not. CHIP8 gives you the number...
The Display

The Keys

1 2 3 C 5: Yes
4: No
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Guess version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 36

Hidden(7) Hidden(7)

NAME
Hidden − find pairs of cards

SYNOPSIS
chip8run hidden
DESCRIPTION
This is a version of the classic memory game. You are asked to find pairs of cards.
The Display
At the openning splash screen, press any key. You will then see the cards.

The Keys

1 2 3 C 2: up
4: left
5: pick
4 5 6 D
6: right
8: down
7 8 9 E

A 0 B F

COPYRIGHT
Hidden version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 37

HPiper(7) HPiper(7)

NAME
hpiper − plumbing game

SYNOPSIS
chip8run hpiper
DESCRIPTION
This probably not the super game you were hoping for, Erik, but it has only been three days. The only
SCHIP feature this game takes advantage of is the higher screen resolution.
OBJECT
You are presented with a 6 row, 10 column grid and a preview panel of 5 pipes. A starting pipe will be
placed on the grid and will in a few seconds start leaking. The object is to lay pipes on the grid to contain
the leak as long as you can. If the water flows onto a empty grid site, onto the side of another pipe or
border, that plumbing job is finished. If you did well enough, you may get another job. Otherwise the
game is over.
HOW TO PLAY
On the bottom and right borders of the grid are grid pointers. The bottom pointer can be moved left with
the (7) key and right with the (8) key. The side pointer can be moved up with the (3) key and down with the
(6) key. (Note: this is identical to the movement keys for Syzygy by Roy Trevino)
Using the pointers, chose a grid site to place a pipe. The pipe to be placed is the one at the bottom of the
preview column. Once a site is chosen, press the (1) key to place the pipe there. You can replace a pipe
already at the grid site with a penalty of one point. You cannot replace a pipe that the water has already
flown through. Trying to do this will make you lose the pipe you were trying to place and also penalize you
one point.
When you have placed all the pipe you wish to for a particular job, you can press the (F) key to make the
water flow fast. You can still lay pipe if you realize you made a mistake, but hurry!
There are ten levels with increasing water flow speed. Level 10’s speed is the same as that for fast. If you
manage to get through level 10, it repeats at that level till you don’t.
SCORING
You receive 3 points for every pipe the water flows through. For the crossed pipes, flowing through them in
both directions gives you 6 points. (Note: some adventuresome combinatorist might want to figure out
what the maximum possible score is. If it is over 255, there could be a problem, but I doubt it.) You are
penalized 1 point for replacing or trying to replace a pipe already on the grid.
The current job score is shown in upper right corner up to 99. If the score goes over 99, the displayed score
rolls over. However, up to 255, the full score is kept in memory.
Once a job is over, the score earned is added to the grand total and displayed on the screen shown after
(SPACE) is pressed. This total has two parts. The first part before the two periods is the total up to 255.
The second part is the number of times the total rolled over. Therefore to get the real total, multiply the
second part by 256 and add the first part. (Note: Sorry about this method, but I haven’t worked out the
preferred way yet.)
If the game is over, the word OVER will be displayed above the score and the (DEL) key must be pressed
to exit. Else, press (SPACE) to go on to the next job. The points needed to go to the next job are obtained
by the following formula:
Points needed = 100 − (41 − 4 * level)
Happy plumbing!
The Display

Reference Manual Chip8 38

HPiper(7) HPiper(7)

The Keys
The keys used are as follows:

1 2 3 C 1: place
3: up
4: uplace
4 5 6 D
6: down
7: left
7 8 9 E 8: right
F: fast
A 0 B F

COPYRIGHT
H. Piper version 2.0
Copyright (C) 1991 Paul Raines
Since CHIP makes use of undocumented features of the HP48SX, anything happen: loss of data, meltdown,
etc. Therefore, I take no responsibility for any damage whatsoever that occurs.
AUTHOR
Paul Raines <vapsppr@prism.gatech.edu>

Reference Manual Chip8 39

Invaders(7) Invaders(7)

NAME
Invaders − a space invaders clone

SYNOPSIS
chip8run invaders
DESCRIPTION
The well known game. Destroy the invaders with your ship.
The Display

The Keys

1 2 3 C 4: left
5: fire
6: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Invaders version 0.9
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 40

Joust(7) Joust(7)

NAME
Joust − arcade game

SYNOPSIS
chip8run joust
DESCRIPTION
Hoorah! Hoorah! Here it is, the latest CHIP48 game; my rendition of the arcade game Joust.
The blank dots in the bottom left corner indicate the number of players left, not including the current
player. Sorry, no bonus guys. Maybe in the future.
At the score screen press A to replay.
If you feel the game is slow, then wait until you get to level 7! The levels roll over at 15, I think. I haven’t
gotten that far! Therefore there maybe unseen bugs.
The game is novel. I’m not sure of its lasting qualities.
The Display

The Keys

1 2 3 C 3: left
C: right
A: up
4 5 6 D
A: At the score screen
7 8 9 E press A to replay.

A 0 B F

Points
1 point per egg touched
8 points for clearing bonus round
1 player for clearing bonus round
COPYRIGHT
Joust version 2.3
Copyright (C) 1991 Erin S Catto
AUTHOR
Erin S Catto <catto@ecn.perdue.edu>

Reference Manual Chip8 41

kaleid(7) kaleid(7)

NAME
kaleid − draw pretty patterns

SYNOPSIS
chip8run kaleid
DESCRIPTION
A little program (not a game) to make funny graphics. Move around the screen with 2 4 6 8. To finish and
make CHIP8 repeat your moves, press 0.
The Display

The Keys

1 2 3 C 0: finish
2: up
4: left
4 5 6 D
6: right
8: down
7 8 9 E

A 0 B F

COPYRIGHT
kaleid version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 42

maze(7) maze(7)

NAME
maze − draws random mazes

SYNOPSIS
chip8run maze
DESCRIPTION
This little program draws random mazes.
The Display

The Keys
Press any key to cause a different maze to be drawn.
COPYRIGHT
maze version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 43

merlin(7) merlin(7)

NAME
merlin − remember the order

SYNOPSIS
chip8run merlin
DESCRIPTION
This is the Simon game. The goal is to remember in which order the squares are lighted. The game begins
by lighting 4 random squares, and then asks you to light the squares in the correct order. You win a level
when you give the exact order, and each increasing level shows a additionnal square. The game ends when
you light an incorrect square. Keys are 4 and 5 for the two upper squares, then 7 and 8 for the two lower
ones.
The Display

The Keys

1 2 3 C 4: left
6: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
merlin version 1.0
Copyright (C) 1998 Unknown
AUTHOR
Unknown <unknown@example.com>

Reference Manual Chip8 44

missile(7) missile(7)

NAME
missile − shoot the targets

SYNOPSIS
chip8run missile
DESCRIPTION
You must shoot the 8 targets on the screen. Your shooter moves a little bit faster each time you shoot. You
have 12 missiles to shoot all the targets, and you win 5 points per target shot.
The Display

The Keys

1 2 3 C 8: fire

4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
missile version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 45

pong(7) pong(7)

NAME
pong − the original video game

SYNOPSIS
chip8run pong
DESCRIPTION
OK folks here it is! Pong for the Chip8.
The game never ends. It keeps score, but only up to 9 for each player, then it will roll over to 0. Sorry, it’s
the only way I could think of to do it. So, you have to play ‘‘whoever gets to a number first, wins.’’
It is kind of slow, but then there are two paddles and ball moving around all at once.
The player who got the last point gets the serve...
The Display

The Keys

1 2 3 C 1: move left paddle up

4: move left paddle down
4 5 6 D
C: move right paddle up
D: move right paddle down
7 8 9 E

A 0 B F

COPYRIGHT
Pong version 1.0
Copyright (C) 1990 Paul Vervalin
AUTHOR
Paul Vervalin <vervalin@austin.lockheed.com>

Reference Manual Chip8 46

puzzle(7) puzzle(7)

NAME
puzzle − X11 Chip8 game

SYNOPSIS
chip8run puzzle
DESCRIPTION
Here is the infamous 15 puzzle for Chip8. The puzzle, as you doubtless recall, has 15 squares numbered 1
through 15 (in this case, 1 through F) and one hole. You can move the hole about and must put the pieces
in order.
When you first run puzzle, it comes up solved. Thereafter, pressing IRestart causes the puzzle to have 32
random moves made, effectively randomizing the puzzle. If 32’s not enough for you, just press IRestart
again.
The program does not check to see if you’ve solved the puzzle, and therefore nothing special happens when
you do except for the warm, fuzzy feeling that you have beaten it.
The Display

The Keys
You enter moves by using the keys. The key’s
1 2 3 C position in that 4×4 matrix corresponds to the square
in that position of the puzzle matrix. Pushing a key
4 5 6 D causes the hole to migrate to that position. The
migration is performed in the order up, down, left,
7 8 9 E right; it is not necessary to limit your moves to those
rows and columns containing the hole; you can
A 0 B F request that the hole move to any position.

COPYRIGHT
Puzzle version 1.0
Copyright (C) 1990 Roger Ivie
AUTHOR
Roger Ivie <slsw2@cc.usu.edu>

Reference Manual Chip8 47

race(7) race(7)

NAME
race − driving game

SYNOPSIS
chip8run race
DESCRIPTION
This game simulates a racing car.
The Display

The Keys

1 2 3 C 7: left
8: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
race version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 48

snake(7) snake(7)

NAME
Snake − navigate the snake through the maze

SYNOPSIS
chip8run snake
DESCRIPTION
In this game, you a guiding the snake to eat apples as they appear. The snake gets longer as it eats the
apples. Each level has 5 apples, and then a small exit will appear.
If you bite the wall, or bite yourself, you lose a life.
The number of lives you have left is displayed in the top left corner.
The Display

The Keys

1 2 3 C 4: turn left
6: turn right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
chip8 version 1.1
Copyright (C) 1990, 1991, 1998, 1999, 2012 Peter Miller
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.
AUTHOR
Peter Miller E-Mail: pmiller@opensource.org.au
/\/\* WWW: http://miller.emu.id.au/pmiller/

Reference Manual Chip8 49

spacefight(7) spacefight(7)

NAME
space fight − space invaders clone

SYNOPSIS
chip8run spacefight
DESCRIPTION
Ok, here’s a little Super-Chip game for all you mad S-Chip-freaks out there!
PURPOSE
The purpose of the game is.... to win (say what?)
In order to complete this quite difficult task your body (yes only your body and not your mind (this remark
shows that I believe that the body merely serves as a tool for the brain)) have been warped through 87
different time-warps due to some foolish scientists who didn’t know what they were doing. This resulted in
a rather big waste of resources but that’s of course another story. When you finally arrive you can’t
recognize anything and two weird-looking dudes tell you that this is the year 2091!!! Frightening eh?
You are of course not very happy about your situation partly because you only have 25 dollars in your
wallet and the prizes have gone up about 30000% but mainly because IBM and the fucking PC clones have
completely taken over all of the computer-market resulting in CHIP8’s death!
In a Holo-BiDirectional-FullDuplex-TV-store you see a newsflash concerning some evil aliens about to
invade the good ol’ EARTH. Scientists think that they are being drawn towards the Earth due to the
massive pollution the PC’s cause. However if people had bought CHIP8’s instead (which don’t pollute)
they would have been no aliens now!
This is your call! You sneak into a Warp-Transporter without a ticket and you end up at NASA where you
get to talk to the boss and you tell him: "OK you listen to me you scumbag! I wanna get into a spacecraft,
get up there and KICK SOME ALIEN BUTT!". "But why?" the boss says. "Personal motives" you
answer. If you can save the CHIP8’s existence you’re ready to do anything!
You get the newest spacecraft (CHIP8) and you take off!
Battle you way through the 6 (increasingly harder) levels!
The Display

Reference Manual Chip8 50

spacefight(7) spacefight(7)

The Keys

1 2 3 C 3: left
A: fire
C: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
spacefight version 1.0
Copyright (C) 1992 Carsten Soerensen
AUTHOR
Carsten Soerensen <u920659@daimi.aau.dk>
Carsten Soerensen
Kronhjortevej 4
DK-8270 Hoejbjerg
Denmark

Reference Manual Chip8 51

syzygy(7) syzygy(7)

NAME
syzygy − navigate the little snake

SYNOPSIS
chip8run syzygy
DESCRIPTION
One of the first games I remember playing on a computer was called "syzygy" on a now ancient TRSH80
Model 1. It has since appeared on other computers under various names. Why it was called syzygy, I have
no idea (consult Websters). However, since the HP48SX has approximately the same memory, graphics
and cpu power as my TRSH80 did (something like 16kB, 128x64, and a 1.2Mhz Z80), I thought it would
be amusing to play it again. Now, approximately to my recollection, and with many apologies to the
original author, here is a CHIP48 version of SYZYGY for the HP48. Enough drivel.
The object of the game is to seek out "targets". You do this with your syzygy. Initially small, the syzygy
will grow by some amount each time a target is hit. Eventually, your syzygy will be so long as to make
tougher and tougher to get any points (and easier and easier to get killed). Confused? Just try it.
Anyways, the syzygy is not allowed to run into anything except targets. It cannot run into the screen border
(if present), or itself (this includes backing into itself). Fast and immediate death will result. Don’t worry
if you die quickly a few times. The keys take a few minutes to get used to.
The Display

The Keys

1 2 3 C 3: up
6: down
7: left
4 5 6 D
8: right
B: Show Score
7 8 9 E E: No Border
F: Border
A 0 B F

COPYRIGHT
syzygy version 0.1
Copyright (C) 1990 Roy Trevino
Noncommercial distribution allowed, provided that this copyright message is preserved, and any modified
versions are clearly marked as such.
SYZYGY, via CHIP-48, makes use of undocumented low-level features of the HP48SX calculator, and may
or may not cause loss of data, excessive battery drainage, and/or damage to the calcultor hardware. The
Author takes no responsibility whatsoever for any damage caused by the use of this program.
THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED

Reference Manual Chip8 52

syzygy(7) syzygy(7)

WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
AUTHOR
Roy Trevino <rtrevino@sedona.intel.com>

Reference Manual Chip8 53

tank(7) tank(7)

NAME
Tank − tank shoots bad guys

SYNOPSIS
chip8run tank
DESCRIPTION
You have 20 missiles to shoot ad the bad guys.
This is one of the original Chip 8 games.
The Display

The Keys

1 2 3 C 2: up
4: left
5: fire
4 5 6 D
6: right
8: down
7 8 9 E

A 0 B F

COPYRIGHT
Unknown 1977
AUTHOR
Unknown

Reference Manual Chip8 54

tetris(7) tetris(7)

NAME
tetris − drop the block

SYNOPSIS
chip8run tetris
DESCRIPTION
Guess what this game is... I’m sure you don’t need the rules. If you do, please ask your friends.
The Display

The Keys

1 2 3 C 4: rotate
5: left
6: right
4 5 6 D
7: drop piece
7 8 9 E

A 0 B F

COPYRIGHT
Unknown
AUTHOR
Unknown

Reference Manual Chip8 55

tictac(7) tictac(7)

NAME
tictac − a tic-tac-toe game

SYNOPSIS
chip8run tictac
DESCRIPTION
A tic-tac-toe game. Play with [1] to [9] keys. Each key corresponds to a square in the grid. The game never
ends, so at any time, the winner is the one who has the best score.
The Display

The Keys

1 2 3 C 1-9: select
corresponding
square
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
tictac version 1.0
Copyright (C) 1991 David Winter
AUTHOR
David Winter <winter@worldnet.net>

Reference Manual Chip8 56

UBoat(7) UBoat(7)

NAME
UBoat − Sink the submarines

SYNOPSIS
chip8run uboat
DESCRIPTION
This game is based on a game that I used to play back in the early 80’s on an Apple ][. I believe the name
of the program was "Depth Charge." Unfortunately I don’t know who was responsible for programming it.
The premise of the game is fairly simple. You are the Captain of a sub hunting destroyer, and your
objective is to sink as many enemy U-Boats as you can. Your only weapon against the U-Boats is your
ship’s supply of depth charges. You have an unlimited supply of charges but, due to the amount of time it
takes your second rate crew to reload, you may only have four charges in the water at any given time.
The subs that you are hunting appear at random depths and have one of three random velocities (stopped,
ahead half, or ahead full). There are six enemy subs visible at any one time. When one of these subs is
destroyed, another will appear at a different location.
The Display

The Keys
The keys used are as follows:

1 2 3 C 7: ship’s speed full stop

8: ship’s speed ahead half
9: ship’s speed ahead full
4 5 6 D
E: drop depth charge
C: abort game
7 8 9 E

A 0 B F

Scoring for the game is based on the depth of the sub, multiplied by one plus it’s velocity. For example: If
a sub is at a depth of 50, and he is stopped then he is worth 50 points. A sub at the same depth of 50, but
moving at 1/2 speed is worth 100 points. A sub at a depth of 50, but moving at full speed is worth 150
points.
The time limit for the game is about 2.5 minutes. At about 1:45 into the game a warning buzzer goes off
and an almost empty hourglass is displayed by your score to let you know that the game is about over.
Once the game is over your score, the high score, the number of charges dropped, the number of subs hit,
and your hit percentage are displayed.
A good game is about 2800 or so, and a really good game is around 3500. I haven’t had a whole lot of time
to play it, but my high is 3551.

Reference Manual Chip8 57

UBoat(7) UBoat(7)

COPYRIGHT
U-Boat version 1.0 (8/8/94)
Copyright (C) 1994 Michael D. Kemper
This game is freeware, and may be distributed freely as long as this doc file remains with it, and both the
doc and program remain unchanged.
(Sorry. I lightly edited it to adapt it to my assembler, and cope with the fact that X11 doesn’t re-map the
keys. Peter Miller)
AUTHOR
Michael D. Kemper <mikek@access.mountain.net>

Reference Manual Chip8 58

ufo(7) ufo(7)

NAME
UFO − space invaders clone

SYNOPSIS
chip8run ufo
DESCRIPTION
You have 15 missiles to shoot on the two types of invaders. The big one moves on the left and gives you 5
points. The small one moves on the right at variant speeds. The game ends after having shot the 15
missiles.
The Display

The Keys

1 2 3 C 4: shoot left
5: shoot up
6: shoot right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Unknown 1977
AUTHOR
Unknown

Reference Manual Chip8 59

VBrix(7) VBrix(7)

NAME
VBrix − Knock out the bricks

SYNOPSIS
chi8run vbrix
DESCRIPTION
This is a version of the classic game of knock out the bricks.
The Display

The Keys

1 2 3 C 1: move paddle up
4: move paddle down
7: start game
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Vertical Brix version 1.0
Copyright © 1996 Paul Robson
AUTHOR
Paul Robson

Reference Manual Chip8 60

vers(7) vers(7)

NAME
vers − two tenuous worms

SYNOPSIS
chip8run vers
DESCRIPTION
There are two players, each controls a worm. The idea is to have the longest worm. First to 8 points, wins.
The Display

The Keys

1 2 3 C 1: Player 1 Left
1: Player 1 Right
7: Player 1 Up
4 5 6 D
A: Player 1 Down
B: Player 2 Left
7 8 9 E C: Player 2 Up
D: Player 2 Down
A 0 B F F: Player 2 Right

COPYRIGHT
vers version 1.0
Copyright (C) 1991 JMN
AUTHOR
JMN

Reference Manual Chip8 61

wipeoff(7) wipeoff(7)

NAME
Wipe Off − wipe off the bricks

SYNOPSIS
chip8run wipeoff
DESCRIPTION
Another BRIX variant, but quite hard to play. Your score is shown when you lose all your lives.
The Display

The Keys

1 2 3 C 4: move paddle left

6: move paddle right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
Unknown
AUTHOR
Unknown

Reference Manual Chip8 62

worm3(7) worm3(7)

NAME
worm3 − navigate the worm to the apples

SYNOPSIS
chip8run worm3
DESCRIPTION
You control the worm. You need to guide it to each of the apples.
The Display

The Keys

1 2 3 C 8: left
9: right
4 5 6 D

7 8 9 E

A 0 B F

COPYRIGHT
worm3 version 1.0
Copyright (C) 1991 Unknown
AUTHOR
Unknown

Reference Manual Chip8 lxiii

Table of Contents(Chip8) Table of Contents(Chip8)

The README File . . . . . . . . . . . . . . . . . . . . . . . . . 1

Release Notes . . . . . . . . . . . . . . . . . . . . . . . . . . 2
How to Build the Sources . . . . . . . . . . . . . . . . . . . . . . . 3
chip8as(1) assemble chip8 programs . . . . . . . . . . . . . . . . . . . . . . . 7
chip8dis(1) disassemble chip8 programs . . . . . . . . . . . . . . . . . . . . . . 8
chip8lic(1) GNU General Public License . . . . . . . . . . . . . . . . . . . . . . 9
chip8run(1) run a chip8 program . . . . . . . . . . . . . . . . . . . . . . . . 14
chip8as(5) chip8 opcodes . . . . . . . . . . . . . . . . . . . . . . . . . . 16
chip8run(5) chip8 file formats . . . . . . . . . . . . . . . . . . . . . . . . . 24
15puzzle(7) game . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
alien(7) Shoot the alien invaders . . . . . . . . . . . . . . . . . . . . . . . 26
ant(7) In search of Coke . . . . . . . . . . . . . . . . . . . . . . . . . 27
blinky(7) PacMan clone . . . . . . . . . . . . . . . . . . . . . . . . . . 28
blitz(7) bomb the bad guys . . . . . . . . . . . . . . . . . . . . . . . . . 30
brix(7) Knock out the bricks . . . . . . . . . . . . . . . . . . . . . . . . 31
car(7) driving game . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
connect4(7) two player join the dots . . . . . . . . . . . . . . . . . . . . . . . 33
field(7) navigate the asteroid field . . . . . . . . . . . . . . . . . . . . . . . 34
guess(7) guess the number . . . . . . . . . . . . . . . . . . . . . . . . . 36
hidden(7) find pairs of cards . . . . . . . . . . . . . . . . . . . . . . . . . 37
hpiper(7) plumbing game . . . . . . . . . . . . . . . . . . . . . . . . . . 38
invaders(7) a space invaders clone . . . . . . . . . . . . . . . . . . . . . . . . 40
joust(7) arcade game . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
kaleid(7) draw pretty patterns . . . . . . . . . . . . . . . . . . . . . . . . . 42
maze(7) draws random mazes . . . . . . . . . . . . . . . . . . . . . . . . 43
merlin(7) remember the order . . . . . . . . . . . . . . . . . . . . . . . . . 44
missile(7) shoot the targets . . . . . . . . . . . . . . . . . . . . . . . . . . 45
pong(7) The original video game . . . . . . . . . . . . . . . . . . . . . . . 46
puzzle(7) game . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
race(7) driving game . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
snake(7) Navigate the snake through the maze . . . . . . . . . . . . . . . . . . . 49
spacefight(7) space invaders clone . . . . . . . . . . . . . . . . . . . . . . . . 50
syzygy(7) navigate the little snake . . . . . . . . . . . . . . . . . . . . . . . 52
tank(7) shoots bad guys . . . . . . . . . . . . . . . . . . . . . . . . . . 54
tetris(7) drop the block . . . . . . . . . . . . . . . . . . . . . . . . . . 55
tictac(7) a tic-tac-toe game . . . . . . . . . . . . . . . . . . . . . . . . . 56
uboat(7) Sink the submarines . . . . . . . . . . . . . . . . . . . . . . . . 57
ufo(7) space invaders clone . . . . . . . . . . . . . . . . . . . . . . . . 59
vbrix(7) Knock out the bricks . . . . . . . . . . . . . . . . . . . . . . . . 60
vers(7) two tenuous worms . . . . . . . . . . . . . . . . . . . . . . . . . 61
wipeoff(7) wipe off the bricks . . . . . . . . . . . . . . . . . . . . . . . . . 62
worm3(7) navigate the worm to the apples . . . . . . . . . . . . . . . . . . . . . 63

Reference Manual Chip8 iii

Permuted Index(Chip8) Permuted Index(Chip8)

alien(7) 26 Alien - Shoot the alien invaders

alien(7) 26 Alien - Shoot the alien invaders
ant(7) 27 ant - In search of Coke
worm3(7) 63 worm3 - navigate the worm to the apples
joust(7) 41 Joust - arcade game
chip8as(1) 7 chip8as - assemble chip8 programs
field(7) 34 Field - mavigate the asteroid field
blitz(7) 30 Blitz - bomb the bad guys
tank(7) 54 Tank - tank shoots bad guys
blinky(7) 28 Blinky - PacMan clone
blitz(7) 30 Blitz - bomb the bad guys
tetris(7) 55 tetris - drop the block
blitz(7) 30 Blitz - bomb the bad guys
brix(7) 31 Brix - Knock out the bricks
vbrix(7) 60 VBrix - Knock out the bricks
wipeoff(7) 62 Wipe Off - wipe off the bricks
brix(7) 31 Brix - Knock out the bricks
car(7) 32 Car - driving game
hidden(7) 37 Hidden - find pairs of cards
chip8as(1) 7 chip8as - assemble chip8 programs
chip8as(5) 16 chip8as - chip8 opcodes
chip8dis(1) 8 chip8dis - disassemble chip8 programs
chip8run(5) 24 chip8 file formats
15puzzle(7) 25 15puzzle - X11 Chip8 game
puzzle(7) 47 puzzle - X11 Chip8 game
chip8as(5) 16 chip8as - chip8 opcodes
chip8run(1) 14 chip8run - run a chip8 program
chip8as(1) 7 chip8as - assemble chip8 programs
chip8dis(1) 8 chip8dis - disassemble chip8 programs
chip8run(1) 14 chip8run - run a chip8 program
blinky(7) 28 Blinky - PacMan clone
invaders(7) 40 Invaders - a space invaders clone
spacefight(7) 50 space fight - space invaders clone
ufo(7) 59 UFO - space invaders clone
ant(7) 27 ant - In search of Coke
connect4(7) 33 Connect4 - two player join the dots
chip8dis(1) 8 chip8dis - disassemble chip8 programs
chip8dis(1) 8 chip8 dis - disassemble chip8 programs
connect4(7) 33 Connect4 - two player join the dots
kaleid(7) 42 kaleid - draw pretty patterns
maze(7) 43 maze - draws random mazes
car(7) 32 Car - driving game
race(7) 48 race - driving game
tetris(7) 55 tetris - drop the block
field(7) 34 Field - mavigate the asteroid field
field(7) 34 Field - mavigate the asteroid field
spacefight(7) 50 space fight - space invaders clone
chip8run(5) 24 chip8 file formats
hidden(7) 37 Hidden - find pairs of cards
chip8run(5) 24 chip8 file formats
15puzzle(7) 25 15puzzle - X11 Chip8 game
car(7) 32 Car - driving game
hpiper(7) 38 hpiper - plumbing game

Reference Manual Chip8 iv

Permuted Index(Chip8) Permuted Index(Chip8)

joust(7) 41 Joust - arcade game

pong(7) 46 pong - the original video game
puzzle(7) 47 puzzle - X11 Chip8 game
race(7) 48 race - driving game
tictac(7) 56 tictac - a tic[hy]tac[hy]toe game
guess(7) 36 Guess - guess the number
guess(7) 36 Guess - guess the number
blitz(7) 30 Blitz - bomb the bad guys
tank(7) 54 Tank - tank shoots bad guys
hidden(7) 37 Hidden - find pairs of cards
hpiper(7) 38 hpiper - plumbing game
tictac(7) 56 tictac - a tic[ hy]tac[hy]toe game
tictac(7) 56 tictac - a tic[hy]tac[ hy]toe game
15puzzle(7) 25 require_ index
alien(7) 26 require_ index
ant(7) 27 require_ index
blinky(7) 28 require_ index
blitz(7) 30 require_ index
brix(7) 31 require_ index
car(7) 32 require_ index
chip8as(1) 7 require_ index
chip8as(5) 16 require_ index
chip8dis(1) 8 require_ index
chip8run(1) 14 require_ index
chip8run(5) 24 require_ index
connect4(7) 33 require_ index
field(7) 34 require_ index
guess(7) 36 require_ index
hidden(7) 37 require_ index
hpiper(7) 38 require_ index
invaders(7) 40 require_ index
joust(7) 41 require_ index
kaleid(7) 42 require_ index
maze(7) 43 require_ index
merlin(7) 44 require_ index
missile(7) 45 require_ index
pong(7) 46 require_ index
puzzle(7) 47 require_ index
race(7) 48 require_ index
snake(7) 49 require_ index
spacefight(7) 50 require_ index
syzygy(7) 52 require_ index
tank(7) 54 require_ index
tetris(7) 55 require_ index
tictac(7) 56 require_ index
uboat(7) 57 require_ index
ufo(7) 59 require_ index
vbrix(7) 60 require_ index
vers(7) 61 require_ index
wipeoff(7) 62 require_ index
worm3(7) 63 require_ index
ant(7) 27 ant - In search of Coke
alien(7) 26 Alien - Shoot the alien invaders

Reference Manual Chip8 v

Permuted Index(Chip8) Permuted Index(Chip8)

invaders(7) 40 Invaders - a space invaders clone

invaders(7) 40 Invaders - a space invaders clone
spacefight(7) 50 space fight - space invaders clone
ufo(7) 59 UFO - space invaders clone
connect4(7) 33 Connect4 - two player join the dots
joust(7) 41 Joust - arcade game
kaleid(7) 42 kaleid - draw pretty patterns
brix(7) 31 Brix - Knock out the bricks
vbrix(7) 60 VBrix - Knock out the bricks
syzygy(7) 52 syzygy - navigate the little snake
field(7) 34 Field - mavigate the asteroid field
snake(7) 49 Snake - navigate the snake through the maze
maze(7) 43 maze - draws random mazes
maze(7) 43 maze - draws random mazes
merlin(7) 44 merlin - remember the order
missile(7) 45 missile - shoot the targets
syzygy(7) 52 syzygy - navigate the little snake
snake(7) 49 Snake - navigate the snake through the maze
worm3(7) 63 worm3 - navigate the worm to the apples
guess(7) 36 Guess - guess the number
wipeoff(7) 62 Wipe Off - wipe off the bricks
wipeoff(7) 62 Wipe Off - wipe off the bricks
chip8as(5) 16 chip8as - chip8 opcodes
merlin(7) 44 merlin - remember the order
pong(7) 46 pong - the original video game
brix(7) 31 Brix - Knock out the bricks
vbrix(7) 60 VBrix - Knock out the bricks
blinky(7) 28 Blinky - PacMan clone
hidden(7) 37 Hidden - find pairs of cards
kaleid(7) 42 kaleid - draw pretty patterns
connect4(7) 33 Connect4 - two player join the dots
hpiper(7) 38 hpiper - plumbing game
pong(7) 46 pong - the original video game
kaleid(7) 42 kaleid - draw pretty patterns
chip8run(1) 14 chip8run - run a chip8 program
chip8as(1) 7 chip8as - assemble chip8 programs
chip8dis(1) 8 chip8dis - disassemble chip8 programs
puzzle(7) 47 puzzle - X11 Chip8 game
15puzzle(7) 25 15 puzzle - X11 Chip8 game
race(7) 48 race - driving game
maze(7) 43 maze - draws random mazes
merlin(7) 44 merlin - remember the order
15puzzle(7) 25 require_index
alien(7) 26 require_index
ant(7) 27 require_index
blinky(7) 28 require_index
blitz(7) 30 require_index
brix(7) 31 require_index
car(7) 32 require_index
chip8as(1) 7 require_index
chip8as(5) 16 require_index
chip8dis(1) 8 require_index
chip8run(1) 14 require_index

Reference Manual Chip8 vi

Permuted Index(Chip8) Permuted Index(Chip8)

chip8run(5) 24 require_index
connect4(7) 33 require_index
field(7) 34 require_index
guess(7) 36 require_index
hidden(7) 37 require_index
hpiper(7) 38 require_index
invaders(7) 40 require_index
joust(7) 41 require_index
kaleid(7) 42 require_index
maze(7) 43 require_index
merlin(7) 44 require_index
missile(7) 45 require_index
pong(7) 46 require_index
puzzle(7) 47 require_index
race(7) 48 require_index
snake(7) 49 require_index
spacefight(7) 50 require_index
syzygy(7) 52 require_index
tank(7) 54 require_index
tetris(7) 55 require_index
tictac(7) 56 require_index
uboat(7) 57 require_index
ufo(7) 59 require_index
vbrix(7) 60 require_index
vers(7) 61 require_index
wipeoff(7) 62 require_index
worm3(7) 63 require_index
chip8run(1) 14 chip8run - run a chip8 program
chip8run(1) 14 chip8 run - run a chip8 program
ant(7) 27 ant - In search of Coke
tank(7) 54 Tank - tank shoots bad guys
alien(7) 26 Alien - Shoot the alien invaders
missile(7) 45 missile - shoot the targets
uboat(7) 57 UBoat - Sink the submarines
syzygy(7) 52 syzygy - navigate the little snake
snake(7) 49 Snake - navigate the snake through the maze
snake(7) 49 Snake - navigate the snake through the maze
spacefight(7) 50 space fight - space invaders clone
invaders(7) 40 Invaders - a space invaders clone
spacefight(7) 50 space fight - space invaders clone
ufo(7) 59 UFO - space invaders clone
uboat(7) 57 UBoat - Sink the submarines
syzygy(7) 52 syzygy - navigate the little snake
tictac(7) 56 tictac - a tic[hy] tac[hy]toe game
tank(7) 54 Tank - tank shoots bad guys
tank(7) 54 Tank - tank shoots bad guys
missile(7) 45 missile - shoot the targets
vers(7) 61 vers - two tenuous worms
tetris(7) 55 tetris - drop the block
snake(7) 49 Snake - navigate the snake through the maze
tictac(7) 56 tictac - a tic[hy]tac[hy]toe game
tictac(7) 56 tictac - a tic[hy]tac[hy]toe game
tictac(7) 56 tictac - a tic[hy]tac[hy] toe game

Reference Manual Chip8 vii

Permuted Index(Chip8) Permuted Index(Chip8)

connect4(7) 33 Connect4 - two player join the dots

vers(7) 61 vers - two tenuous worms
uboat(7) 57 UBoat - Sink the submarines
ufo(7) 59 UFO - space invaders clone
vbrix(7) 60 VBrix - Knock out the bricks
vers(7) 61 vers - two tenuous worms
pong(7) 46 pong - the original video game
wipeoff(7) 62 Wipe Off - wipe off the bricks
wipeoff(7) 62 Wipe Off - wipe off the bricks
worm3(7) 63 worm3 - navigate the worm to the apples
vers(7) 61 vers - two tenuous worms
worm3(7) 63 worm3 - navigate the worm to the apples
15puzzle(7) 25 15puzzle - X11 Chip8 game
puzzle(7) 47 puzzle - X11 Chip8 game

Reference Manual Chip8 viii