Spacewar! (re)sources

Here are some collected resources on Spacewar! (1962 digital video game):

• spacewar_2b_25mar62.txt
  Authentic listing of Spacewar 2B.
  This version features minor differences as compared to the binary object tapes "spacewar2B_2apr62.bin" and "spaceWar_SA-5.bin" (see below) regarding reversed polarities (on/off) for sense switch settings.
  (Requires the common macro definitions and the starfield data.)
• hyperspace85.txt
  Authentic source code of "hyperspace85.bin", the orignial hyperspace patch by J.M. Graetz ("Hyperspace VIci, 2 May 1962", recoded in October 1985) for Spacewar! 2B (see above).
  The "Minskytron hyperspace" as described in "The Origin of Spacewar" by J. M. Graetz.
  (Requires the common macro definitions in macro fio-dec system.)
• spacewar_2b_2apr62.txt
  Reconstructed PDP-1 Macro source code of Spacewar! 2B as in the binary tapes "spacewar2B_2apr62.bin" and "spaceWar_SA-5.bin".
  (Includes the source code of the "macro fio-dec system" and the starfield data which are not included in "spacewar_2b_25mar62.txt".)
• macro_fiodec_jun63.txt
  The macro definitions of the "macro fio-dec system" as of June 1963.
• stars_by_prs_for_sw2b_mar62.txt
  The starfield data (13 Mar. 1962) for the Expensive Planetarium by Peter Samson, originally for Spacewar! 2B and included in all versions of Spacewar!.
• spacewAutoRestartPatch.txt
  Reconstructed source code of the auto-restart patch for Spacewar! 2B, requires hyperspace85.txt. — Compare hyperspace85_disassembly.txt.
• spacewar3.1_complete.txt
  Spacewar! 3.1 PDP-1 Macro source code, for comparision (diff).
  Source is as http://bitsavers.org/bits/DEC/pdp1/papertapeImages/20031202/SteveRussell_box1/_text/.
• spacewar-senseswitches.txt
  Spacewar! sense switch settings demystified (based on the actual source code).
• spacewar_2b_disassembly.txt
  The commented disassembly of Spacewar! 2B (2 April 62), the reconstructed source code (see above) is based on.
• hyperspace85_disassembly.txt
  Disassembly of the "hyperspace85.bin" patch.
  This is the original hyperspace patch by Martin Graetz featuring the "hyperspace Minskytron signature", to be applied to Spacewar! 2B. — See the images in "The Origin of Spacewar" by J. M. Graetz.
  Please note that this is now obsolete, since the authentic source code has been rediscovered since (see above).
• spaceWarRstrt_disassembly.txt
  Disassembly of the auto-restart patch, as in "spaceWarRstrt.bin" and "spacewAutoRestartPatch.bin".
  To be applied to Spacewar 2B!, patches "hyperspace85.bin" (see above).
• spacewar4_3f.txt
  Source code of Spacewar! 4.3 ddp with fixed Needle Ego Mode (sense switch 2) and simplified control readings in the scorer. N.L. 2/28/2015.
• spacewar4_4.txt
  Source code of Spacewar! 4.4 (ddp 5/21/63) by Monty Preonas and Joe Morris.
  spacewar4_4f.txt — source of the fixed game (N.L. 5/12/2015), not an authentic game!

Mods:

• spacewar2015.txt
  My personal flavor of Spacewar!: Based on Spacewar 4.1 (dfw), features a Needle Ego Mode (sense switch 2), a modified version of the 4-8-score display, and a Minskytron hyperspace signature. N.L. 3/21/2015.
  RIM-tape (binary): spacewar2015.rim (this is not an authentic game!)
• spacewar_2b_m_2016.txt
  A reconstruction of Spacewar 2B as seen at the MIT Science Open House in May 1962, ported for use with a PDP-1 with the automatic multiply/divide option. Compare The Spacewar 2B Preservation Project.
  RIM-tape (binary): spacewar_2b_m_2016.rim (this is not an authentic game!)
• spacewar1_early1962_reconstructed.txt
  A reconstruction of Spacewar 1 as of early 1962, before gravity and the outline compiler were added. (Reconstruction: N.L. Apr. 2016, updated Apr. 2021.)
  THIS IS NOT AN AUTHENTIC PROGRAM.

Other resources:

• macro1.c
  C-version of the PDP-1 Macro assembler, which compiles these sources.
  Version: macro1.c,v 1.73 2003/10/23 22:49:45 phil Exp
  Author(s): Gary A. Messenbrink, modified by Bob Supnik, reworked to work "more like real MACRO" (it does) by Phil Budne. (The program is based on a pal assembler by Douglas Jones and Rich Coon.)
• minskytron-hyperspace-howto.txt
  A guide to adding the Minskytron Hyperspace Signature of the original hyperspace patch (see above) as an animation to Spacewar! 4.1 (2/20/63 dfw), N.L. 2015-05-06.
• snowflake_sa-100.txt
  Disassembly of "snowflake_sa-100.bin", N.L. 2019-01-11.

Spacewar! was conceived in 1961 by Martin Graetz, Stephen Russell, and Wayne Wiitanen. It was first realized on the PDP-1 in 1962 by Stephen Russell, Peter Samson, Dan Edwards, and Martin Graetz, together with Alan Kotok, Steve Piner, and Robert A Saunders. — Spacewar! is in the public domain, but this credit paragraph must accompany all distributed versions of the program.

All sources are provided in a format to be used with the modern C-version of the Macro assembler, macro1.c, namely using a backslash (\) as a prefix to any assembler variables (while originally denoted by an overstroke in the name).

Authentic soures and images of binary paper tapes of Spacewar! are available at bitsavers.org/bits/DEC/pdp1/papertapeImages/.
Some articles on the internals of Spacewar! may be found at www.masswerk.at/spacewar/inside/.

https:// www.masswerk.at / spacewar / sources