Acorn Atom Emulator v1.33
NL version
This page has been created on tuesday 11th november 1997,
Last update made on saturday august 14th 1999 by Wouter Ras .
Naar inhoudsopgave der handleidingen

The Acorn Atom ... A small, but very flexible British home computer, released in 1979. With only 12 kB ROM nd 12 kB RAM as a standard, programs could be made pretty easily, as long as they were not too complicated. However, thanks to quite a number of (EP )ROMs and the Atom's flexible structure, the Atom could be extended with a wide variety of possibilities.
With the Acorn Atom emulator, it is now possible to run almost all the Atom programs on your PC.

The Emulator

The emulator pack is a ZIP compressed archive, containing the following files:
Atom.Exe- The emulator,
AtomCom.Exe- A utility to transfer data from and to tape or an original Atom,
AtomTape.Exe- A utility to retrieve files from tape or an original Atom,
TapeCat.Exe- A utility to index original Atom tapes,
TapeDir.Exe- A utility that shows the contents of a .Tap file,
ReadMe.1st- A text file containing the latest information,
ExtROM.Tap- A tape image containing a number of extension toolboxes,
Example.Tap- A tape image with a few programs that make use of the new toolboxes,
*.Doc- Documentation.


Here are two action shots taken from the emulator. It supports sound through the PC-speaker and through a SoundBlaster or compatible soundcard. The emulator is 100% assembler, and therefore a 486 DX 40 MHz is already enough to run emulation at original sp eed, with full screen updates. The picture on the left was taken from Plane & Tank Battle (programmed 20th - 22nd march as an excuse for not having to learn about spalling forces on steel fibre reinforced concrete). The picture on the right shows a snapsh ot from the game 'Snapper'.

ptbattle.gif snapper.gif

Atom files

In the past few months, I've done nothing with the emulator anymore. And I don't think there will be a lot of Atom software still out there that's not already on this page. However, if anyone has more Atom programs yet, I'd love to see them.

Source Code

I have gotten numerous requests to release the source code. I have been reluctant to do that, because I wasn't sure how many bugs the program contained. But now I'm pretty confident that it should be almost bugfree, and therefore it is now possible to download the source code. Please refer to the download area later on this page.

Dutch manual

Pascalle Leurs has translated the original manual into a dutch version which is included on this CD-ROM: click here: HANDLEIDING.

Version history

Upgrade v1.0 --> v1.1:
On first sight nothing is new from version 1.0. However, emulator v1.1 runs in VGA mode 12h in stead of 13h, because on some graphic adapters a stable screen could not be achieved. I hope this solves the problem.

Upgrade v1.1 --> v1.2:
The following changes have been made:
  • Data can be loaded in memory range A000h-AFFFh. Other ROM areas cannot be overwritten anymore.
  • A bugfix: The AND absolute command now also does I/O operations.
  • Another bugfix: Sometimes files misteriously disappeared and reappeared or could not be imported. Simply by resetting the internal error flag (used for checking I/O operations by Turbo Pascal) prior to opening files, this problem now seems to have dis appeared.
  • Yet another bugfix: Loading of the extension ROM, specified in the .INI-file didn't work. It should be OK now.
  • Hotkeys changed.

Upgrade v1.2 --> v1.21:
  • Partial implementation of undocumented PPIA port D at B003h.
  • Optional disassembly of illegal opcodes in desktop monitor.

Upgrade v1.21 --> v1.22:
  • Error in v1.21 fixed: Memory 0000h-9FFFh RAM and C000h-FFFFh protected against overwriting by loading.
  • On some computers the monitor would go into Stand-by mode as soon as the emulator was started. With help from Jens-Vagner Andersen of Denmark, this problem could be solved.

Upgrade v1.22 --> v1.30:
  • *CAT command ROM-trapped.
  • Debugging options expanded. Up to four independent "real" breakpoints can be set at a time. Special keys ([F4], [F5], [F6], [F12], [Shift+F12] and [Ctrl+F12]) now can also be used when in debug mode.
  • Parallel memory boxes at A000h. Up to 8 EPROMs can be used at the same time. Automatic smart-switching included. Manual switching through I/O-port at BFFFh.
    It is now no longer possible to overwrite the memory area at A000h-AFFFh by loading.
  • The FIN, FOUT, GET, BGET and FGET functions and the SGET, PUT, BPUT, FPUT and SPUT statements have been implemented.
  • MS-DOS shell available (Temporarily go to MS-DOS).
  • Output to printer implemented.

Upgrade v1.30 --> v1.31:
  • Screen capture to .BMP file.
  • Mouse support implemented.
  • Floppy Disk Controller 8271 and DOS implemented.
  • Disk screen in emulator desktop added.
  • Maximum number of parallel toolboxes at A000h expanded to sixteen.

Upgrade v1.31 --> v1.32:
  • Sound output through PC-speaker improved,
  • 65C02 emulation in stead of 6502,
  • Seven extra 65802 instructions, one of which gives access to the second accumulator,
  • Boot from disk image in drive 0, by pressing [Alt+F12] simultaneously,
  • Alternative Floating Point ROM with 80x87 co-processor support (c) by Leendert Bijnagte.

Upgrade v1.32 --> v1.33:
  • Communication capabilities expanded. The Atom's I/O ports at B400h-B7FFh have now beenlinked to the PC's I/O ports 0000h-03FFh, for communication between emulator and other devicesand/or programs.


The Acorn Atom Emulator is freeware. I have written it mainly for nostalgia reasons and secondly because I think the Acorn Atom just is a great product!
See also In the directory sites for the latest info about this emlator.

(14 aug 99)
Atom.Exe v1.33
AtomCom.Exe v1.10
AtomTape.Exe v1.1
TapeCat.Exe v1.00
ExtROM.Tap (AXR1, P-Charme, Gags v2.3, WE-ROM, A&F Utility Kit, ComBox, Salfaa v2.6, Mouse-Dos Box v1.01, Atomic Windows v1.0)
(29 jan 98)
Applic1.Tap (AXR1 Demo, Atom Music, Eliza, Shape Edit, Basic Compiler, Atom Lisp, Towers of Hanoi, Eight Queens, Kl. Beest, Fourier)
Games1.Tap (Attack, Babies, Backgammon, Chess, Dodgems, Dogfight, Fighter, Four Row, Frogger, Galaxians, Invaders, Martians, Mastermind, Minotaur, Missile Base, Rat Trap, Robots, Snake, Snapper, Stargate, Star Trek, Zombie)
Games2.Tap (Break Out, Co-Ord, Invade, Galgje, Ski-Run, Amazing, Bone Hunt, Asteroid Belt, E.T. Invaders, Solitaire, Pontoon, Beetle, Yahtzee)
(13 dec 97)
Graham.Tap (Reversi, Super Othello, Dominoes, Snooker, Invaders, Acorn Chess)
(28 mar 98)
Adventur.Tap (Dungeon, House, Intergalactic, Atomia Akorny, Sphinx)
(19 feb 98)
Magnus1.Tap (Super Zombie, Masken, Star Trek +, MegaLife, Condot, Eliza, Ghost Maze, Hammurabi, Hunt the Wampus, Katakomb, Kong, MadLib, Scramble)
Magnus2.Tap (Backgammon, Checkmate, DFC700, Diamonds, Dragon A, Dragon B, Dragon C, Lunar Lander)
(29 jan 98)
Steve.Tap (747, Asteroids, Break Out, Chess, Fruit Machine, Invader Force, Labyrinth, Nudger, Pinball)
(29 jan 98)
Leendert.Tap (3d-Asteroids, 3d-Four in a Row, 3d-Maze, Astrobirds, Atomica, Awari, Ballistics, Bandit, Blitz, Break Out, Centipede, Cupball, Cylon Attack, Dammen, Drive, Early Warning, Fractal, Hexpawn, Hyperdrive, Lunar Lander, Maze Game, Minefield, Omega Mission, Piet Hein, Piramide, Planetarium, Protect, Puckman, Rally, Reversi, Schiphol, Simon 2, Skiing, Space Battle, Space War, Swarm, Torpedo Run, Trap, Warlords, Wiggle, Zeeslag)
(1 mar 98)
Friso.Tap (Business Game, Constellation, Demon Dungeon, Pilot, Pinball, AtomCalc, BreakOut, Lemon)
(6 mar 98)
(14 may 98)
Menno1.Tap (Amoeba, Badin, Bell Hop, Brains, City Bomber, Cluedo, Dobbel, Golf, Gomoku, Moon Patrol, Pengo, P&T-Battle, Q-Bert, Shoot Out, Simon, Stock Car, Stowaway, Subhunt)
Wordpack.Tap (Ed64)
(14 may 98)
DemoDisk.Dsk (Intro, Atomic Windows Demo, IconMaker, Minesweeper, Panic, Polecat, Space Zap, Rubik's cube, Painter, Boeing 747, Aman, Pattern, Contour, Surface, Rotation)
(14 aug 99)


The software collection on this page and the state that the emulator is in at this moment could not have been possible without the following people:
  • Leendert Bijnagte, who sent me a lot of software and supported me with b-testing. He is also the programmer of the new FP-ROM with 80x87 support.
  • Graham Fowler.
  • Friso de Haan.
  • Henk van der Heijden, who gave me an Atom, a BBC and an Electron. Due to his encouraging comments, the Atom DOS is now supported in the emulator.
  • Menno Lauwerens, who gave his own home-built Atom away to me (which really put my attention to implementing the parallel toolboxes at A000h). It's a beauty, with two disk drives, a self-made monitor and a transformer, bought from IBM for 25 cen ts per kilo. The disks contained quite a lot of software, including some nice programs by Menno himself, like Moon Patrol, Pengo...
  • Roland Leurs, creater of the Atom-in-PC, who sent me "Gokkast", and who gave me a lot of feedback.
  • Magnus Olsson, who gave me feedback and came up with a lot of good ideas.
  • Steve Webster (It took me some time, but the TapeCat utility has been born!)
  • Phil Mainwaring, Jens-Vagner Andersen and everybody else, who came up with comments, questions, ideas etc. to help me fix bugs and expand the emulator. Just keep on sending it...
Naar inhoudsopgave der handleidingen