Acorn Atom Emulator v1.33

Introduction

The Acorn Atom... A small, but very flexible British home computer, released in 1979. With only 12 kB ROM and 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.

Pictures

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 speed, with full screen updates. The picture on the left was taken from Plane & Tank Battle (programmed 20th - 22nd march 1998 as an excuse for not having to learn about spalling forces on steel fibre reinforced concrete). The picture on the right shows a snapshot from the game 'Snapper'.

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 disappeared.
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 been linked to the PC's I/O ports 0000h-03FFh, for communication between emulator and other devices and/or programs.

Downloading

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!

*File:*	*Contents:*
Atom.Zip (14 aug 99)	Atom.Exe v1.33 AtomCom.Exe v1.10 AtomTape.Exe v1.1 TapeCat.Exe v1.00 Tapedir.Exe Atom.Doc AtomCom.Doc TapeCat.Doc ReadMe.1st 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) Example.Tap Gags.Doc WE-ROM.Doc ComBox.Doc Salfaa.Doc P-Charme.Doc AtomicW.Doc MD-Box.Doc
Tape1.Zip (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) Games1.Doc
Graham.Zip (13 dec 97)	Graham.Tap (Reversi, Super Othello, Dominoes, Snooker, Invaders, Acorn Chess)
Adventur.Zip (28 mar 98)	Adventur.Tap (Dungeon, House, Intergalactic, Atomia Akorny, Sphinx) Adventur.Doc Atomia.Doc Atomia.Sol
Magnus.Zip (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) Magnus1.Doc Magnus2.Doc
Steve.Zip (29 jan 98)	Steve.Tap (747, Asteroids, Break Out, Chess, Fruit Machine, Invader Force, Labyrinth, Nudger, Pinball) Steve.Doc
Leendert.Zip (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) Leendert.Doc
Friso.Zip (1 mar 98)	Friso.Tap (Business Game, Constellation, Demon Dungeon, Pilot, Pinball, AtomCalc, BreakOut, Lemon)
Roland.Zip (6 mar 98)	Gokkast.Tap
Menno.Zip (14 may 98)	Fruitma.Tap 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) Poker.Dsk
Erik.Zip (16 jan 01)	Erik.Tap Erik.Txt
DemoDisk.Zip (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)
Source.Zip (14 aug 99)	Atom.Pas FDC8271.Pas AtomTape.Pas AtomCom.Pas TapeCat.Pas TapeDir.Pas TapeDir.C
RomDisas.Zip (20 jan 01)	C000.Txt D000.Txt F000.Txt

Credits

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 cents 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 lots 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!)
Erik Agrell, who sent me software, he managed to get from a very old tape. Thank you for all your efforts.
Tim Herklots, who sent me the disassemblies, with reverse-engineered comments, of the 3 Atom ROMs software. These may be freely distributed.
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.

Links

Website for Atom-in-PC by Roland Leurs at http://skyscraper.fortunecity.com/module/208
The anally retentives retro games home at http://www.arrgh.demon.co.uk/
Keith Howell's homepage at http://www.howell1964.freeserve.co.uk/Acorn/Atom/Atom.htm

Future

About a year ago, I started working on a Windows version of the emulator (looking exactly the same as the DOS based one). The main reason was that it would be much easier to do the correct timing (Let DirectX do it all for you). The DOS one works perfectly on my (ancient) Pentium 233 MHz. However, on many other computers, with different graphic cards, the timing appeared to be not very good.
This project has stranded somewhere in june, but maybe someday I will pick it up. The largest problem is that I can't find the time anymore. The second largest problem is the sound emulation. If anybody can give me some hints, please mail me.

This page has been created on tuesday 11th november 1997,
Last update made on saturday 20th january 2001 by Wouter Ras.