Imlac Software Library

These files are images and documentation for various imlac PDS-1 programs. Some are meant to be run only on long vector machines, as they may otherwise cause the deflection amplifier(s) to overheat and burn out. Please be careful. These images would typically be loaded over the serial port using the binary loader that was either toggled in by hand on the console, or which was held in the diode ROM boot loader board.
Look here for some useful programs which I use to load these images into the Imlacs.
The size in (bytes) is shown for each file:
  • blinkg (7454)
  • The game of checkers - check (5990)
  • Documentation for the game of checkers - check.doc (1265)
  • A clock - clock (13544)
  • core16k (1120)
  • coreop (1938)
  • Something to do with crash analysis? - crash (204)
  • Transfer a crash dump over the serial port? - crashmit (2765)
  • cubic (3548)
  • debug (1954)
  • debug2 (4330)
  • A terminal program (I think) - dts (2462)
  • A game - imquad (4204)
  • A keyboard diagnostic - keybrd (7106)
  • The lemming war game - lemwar (2006)
  • The game of life - life (2298)
  • Mazewar (I think) - maze (1422)
  • A game - munch (322)
  • An apollo lander game - newapollo (14175)
  • A new version of space war - nspwar (4406)
  • A pinball simulator - pinball (6436)
  • A graphics library? - pixlib (35222)
  • The game of pong - pong (14640)
  • Imlac ROM3 simulator - rom3 (214)
  • Imlac ROM3 simulator source - rom3.i (463)
  • A tiger/prey game - snarf (13783)
  • Documentation for the tiger/prey game - snarf.doc (296)
  • A spacewar game - spwar (3204)
  • ssv (11374)
  • A terminal program - sts (6786)
  • A diagnostic - t_dt8level (1760)
  • A diagnostic - t_longvec (1142)
  • A diagnostic - t_lowmem (572)
  • A diagnostic - t_upmem (566)
  • A tank battle game - tank (3654)
  • Documentation for the tank battle game - tank.doc (941)
  • A Tektronix graphics terminal simulator - teksim (7174)
  • tis (16160)
  • tse4 (6158)
  • Another spacewar game - war (19669)
  • A hunt the wumpus game - wumpus (6442)
  • Possibly another space war game - xpw (8324)
  • A WYSIWYG editor - yogi (9674)
  • Documentation for the WYSIWYG editor - yogi2.doc (2047)
  • More documentation for the WYSIWYG editor - yogireq.doc (1807)


    • The following are definitely short vector programs and such.
  • Source for the short vector binary loader - binldr.i (1861)
  • Assembled source for the short vector binary loader - binldr.list (4059)
  • A short vector game of checkers - check (5804)
  • Documentation for the short vector game of checkers - check.doc (2055)
  • A short vector tiger/prey game - snarf (3066)
  • A patch to the short vector tiger/prey game - snarf2.i (475)
  • A short vector terminal program - sts (3972)
  • An older version of the short vector terminal program - stsold (3820)
  • A short vector tank battle game - tank (3584)
  • Documentation for the short vector tank battle game - tank.doc(1784)
  • A patch to the short vector tank battle game - tank2.i(162)


    • Some of these descriptions are guesses as it has been a long time since I actually ran any of them. Some of the games are multi-player, with two players using keys on different parts of the same keyboard to control their ship or tank or whatever. Mazewar may be a multi-player game where each player ran on their own Imlac, connected to each other via a serial port. The game called "snarf" is quite fun. I programmed a version of this game as a video mode in the pinball game Johnny Mnemonic back in 1995.

    With the help of Al Kossow, I was able to obtain images of a box of Imlac paper tapes that I've had sitting around forever. These are the images from those tapes.
  • 2locFltPtMathSrc.ptp
  • 40tp_blockPunch1.0.ptp
  • 40tp_debugger5.0.ptp
  • 40tp_eightLevelTest2.1AlphaGraphic.ptp
  • 40tp_lightPen1.0.ptp
  • 40tp_loSpeedAssm601.ptp
  • 40tp_longVectorTest.ptp
  • 40tp_simpleDisplay.ptp
  • 40tp_spacewar2.5.ptp
  • 40tp_symFormII_1.2C1_8kg.ptp
  • 40tp_tse-4_supGrid.ptp
  • 40tp_ttyio.ptp
  • 40tp_upperMemTest1.ptp
  • checkAxprimIGSR_fortranSrc.ptp
  • fortranARDSsrc.ptp
  • integerMath.ptp
  • lowerMemTest1.ptp
  • unlabeled.ptp


    • I've finally gotten around to scanning some of the old Imlac documents as well. Note that some of these files are large and as my uplink speed is fairly slow, they will take a while to load. Please be patient. Also some of these documents are mirrored here for faster access.
  • List of available Imlac options - IMLAC_PDS-1_OPTIONS_DESC_030871.pdf (620033 bytes)
  • Imlac User Forum Meeting Minutes 11/01/1971 - IMLAC_Users_Forum_Vol1.3_110171.pdf (497100 bytes)
  • Imlac User Forum Meeting Minutes 04/01/1971 - IMLAC_Users_Forum_Vol2.1_040172.pdf (637757 bytes)
  • PDS-1D Programming Guide - PDS-1D_ProgrammingGuide.pdf (035651 bytes)
  • PDS-1 Schematics - PDS-1_Schematics.pdf (14028582 bytes)
  • PDS-1D Schematics - PDS-1D_Schematics.pdf (6897975 bytes)
  • PDS-1 Technical Manual - PDS-1_TechnicalMan.pdf (3380958 bytes)
  • Paper tape punch program documentation - blockpunch.pdf (195774 bytes)
  • Paper tape punch code source - blockpunchsrc.pdf (451325 bytes)
  • Checkers game documentation - checkers.pdf (334430 bytes)
  • Debba's birthday game documentation - debbasbirthday.pdf (350493 bytes)
  • Debugger 5.0 documentation - debugger.pdf (1335802 bytes)
  • Debugger 4.0 code source - debugger4.0src.pdf (2608395 bytes)
  • DT 8 level test documentation - dttest.pdf (235756 bytes)
  • Iomec disk drive manual - iodisc2002.pdf (14318061 bytes)
  • Loading the PDS-1 documentation - loading.pdf (1159989 bytes)
  • Long vector test program documentation - longvectest.pdf (300131 bytes)
  • Lower memory test code source - lowermemorytest.pdf (365032 bytes)
  • Low speed assembler documentation - lowspeedassembler.pdf (1388922 bytes)
  • Memory test documentation - memtest.pdf (478057 bytes)
  • Spacewar game documentation - minispacewardoc.pdf (235681 bytes)
  • Spacewar game code source - minispacewarsrc.pdf (5037133 bytes)
  • Snarf game documentation - snarf.pdf (479902 bytes)
  • Special TTY reader for loading PDS-1 via time sharing documentaiton - specialtty.pdf (342990 bytes)
  • TIO (Teletype Input Output) program documentation - tio.pdf (708325 bytes)
  • TIO (Teletype Input Output) code source - tiosrc.pdf (4313557 bytes)
  • Upper memory test code source - uppermemorytest.pdf (329010 bytes)