AMOS | Code Like It's 198x

For many Amiga owners, AMOS was where programming started. Published by Mandarin Software in June 1990, it was a BASIC built for the things Amiga owners actually wanted to make: sprites and bobs moving over scrolling, multi-layered screens, sampled sound and tracker music, all from commands short enough to type in an afternoon. CU Amiga’s reviewer, who had learned BASIC on “my rusty old Spectrum”, found it “a piece of cake” and closed with a prediction: “It looks like the days of the machine code programmer are numbered.”

Over the next five years its users wrote games, demos, utilities and disk magazines with it, and clubs, magazines and a dedicated public domain library grew up around it.

Fast facts

Author: François Lionet
Publisher: Mandarin Software, later known as Europress Software (Europress)
Released: 12 June 1990 (version 1.1), £49.99
Predecessor: STOS on the Atari ST
Later versions: AMOS Compiler and AMOS 3D (1991), Easy AMOS and AMOS Professional (1992), AMOS Professional Compiler (1993)

From STOS to AMOS

AMOS had a predecessor on the Atari ST. STOS was written by the French software house Jawx; Mandarin took it up, spent six months improving it, and released it in 1988 at £29.95, when The Games Machine called it “an absolute bargain”. CU Amiga later called STOS “the surprise ST hit of late 1988”. A 1995 history of AMOS in Amiga Shopper put the first lines of STOS in 1986. The same magazine recorded that Lionet’s first game had been Chicken Chase, for the Commodore 64, published in Britain, it said, by Rainbird; period advertisements list it in Rainbird’s sister label Firebird’s cheap range instead.

By 1989, Amiga Shopper’s history continues, Lionet had begun an Amiga version, and he finished it while doing his military service in France. Mandarin first promised it for January 1990. That March Amiga Format reported it had slipped to “at least May”, because the manual was not finished: “We could just knock together a manual in a week or so, but we want AMOS to be as near to perfection as is possible,” said Mandarin’s Chris Payne. Mandarin had moved all the programmers and beta testers who had worked on STOS onto AMOS demos and games.

What it did

Amiga Format’s April 1990 preview, by Jason Holborn, set out the pitch. AMOS could open several screens at once, each with its own resolution, size and palette, including the Amiga’s HAM and Extra Half-Brite modes, and load an IFF picture with a single command. It drove the hardware sprites, and for anyone who found those too restricting it had blitter objects, or bobs, as many as memory allowed, with AMOS doing the double-buffering “which is something that assembler programmers have to do themselves!” It gave access to the blitter and copper, and it played music written in its own tracker-style editor or imported from Sonix, Sound Tracker and Game Music Creator.

The part that set AMOS apart was AMAL, the AMOS Animation Language: a small second language for describing how objects moved, so that a sprite could follow its path while the main BASIC program got on with the game. An included editor let you build a movement path by clicking out points on screen.

The finished package came with a sprite editor, a map editor, a 300-page manual with more than 80 example programs, and example games to play and pull apart: Magic Forest, a platform game, AMOSteroids, the adventure Castle AMOS and the educational Number Leap. Mandarin also offered to publish programs good enough to sell.

What the magazines said

The launch reviews in the summer of 1990 were warm. CU Amiga liked its “straightforward English commands that do exactly what you’d expect. To move an onscreen object, such as a sprite, you use the command MOVE.” ACE pointed out that, unlike STOS, AMOS BASIC did without line numbers and indented its listings to show loops and other structures, and called it “an improvement on STOS, and definitely a must for Amiga users who would like to be able to develop their own games, but can’t face the thought of learning machine code”. It had two complaints: the support programs were undocumented, and until a compiler arrived AMOS remained “little more than a powerful toy”.

AMOS entered the software charts in its first month on sale. By December 1990 Mandarin’s advertisements claimed it had passed 25,000 copies, and in November 1991 they spoke of “over 40,000 users”. These are the publisher’s own figures.

The compiler and the family

The compiler ACE had asked for arrived in 1991. Until then, sharing an AMOS program meant bundling RAMOS, a separate run-time module that Amiga Format found took up “masses of space” and “never quite seems to work properly anyway”. The AMOS Compiler, reviewed by Amiga Format in September 1991, turned programs into stand-alone machine code, with a cruncher to halve their size. Mandarin claimed most programs ran at least twice as fast, with some commands up to five times quicker. An AMOS 3D extension was on sale by October 1991.

Easy AMOS, reviewed by Amiga Computing in May 1992, was a version for beginners. It left out a few features, such as menus, and added some of its own, including playing Soundtracker music without conversion. Its 400-page manual was written by Mel Croucher, “humorous and informative” with plenty of cartoons, according to Amiga Computing’s AMOS column.

AMOS Professional followed in late 1992 at £69.99, from a publisher that now called itself Europress Software. Amiga Computing’s Phil South found it “takes Amos forward into the 90s”, with a new editor and a monitor for stepping through programs, borrowed from Easy AMOS. Europress’s advertisements promised 200 new commands, taking the total past 700, and a manual by Croucher and Stephen Hill, who had written the original. A separate AMOS Professional Compiler was on sale by the autumn of 1993.

The AMOS scene

AMOS grew a community of its own. By the end of 1990 an AMOS Club in Barnstaple claimed more than 1,000 members, and a public domain library run by Sandra Sharkey in Wigan had more than 50 disks. The official AMOS PD library, set up with Europress’s help, passed to Len and Anne Tucker in Swansea in 1992; the Tuckers also produced the magazine Totally AMOS. Sharkey went on running Déjà Vu, a licenseware label for AMOS programs. Amiga Computing and Amiga Shopper both ran regular AMOS columns full of readers’ code.

Most AMOS programs went out through public domain libraries, shareware and magazine cover disks. Amiga Shopper’s AMOS column recommended the PD games Scorched Tanks and Xap alongside Jetstrike, a full-price commercial game written in AMOS. The same column’s author got his own game, Extreme Violence, onto Amiga Power’s cover disk in April 1993 and found that most of his shareware registrations came from its readers.

AMOS also carried a stigma. At first Europress insisted that programs written with it showed the AMOS logo on their title screens, and publishers were wary of anything made with a “game creator”. Amiga Shopper ran articles on how to disguise an AMOS program. Its own AMOS columnist thought that was a waste of effort: “anyone with any technical skill can find out anyway, and most people are more likely to be worried about what your game actually looks and plays like”.

After Europress

The newer Amigas brought competition. By early 1994 Amiga Shopper reported that many AMOS programmers were tempted by Blitz Basic 2, which could already program the AGA chipset of the A1200 and A4000, and that Europress had told the magazine Lionet had stopped working on AMOS; an official AGA extension had been dropped. Europress stopped distributing AMOS in 1994. At the end of 1995 a company called Ultimate Software announced plans to re-release AMOS Professional.

Lionet’s AMOS Professional source code is now public. Its official repository, published under the MIT licence, says the AMOS sources were first released into the public domain on 1 December 2012.

Sources

Commodore User, November 1985: Firebird “Super Silver” advertisement listing Chickin Chase.
The Games Machine, issue 12, November 1988: STOS review (Jawx, Mandarin’s six months of work, £29.95, “an absolute bargain”).
Amiga Format, issue 8, March 1990, p. 7: “AMOS Update” (the delay to May, Chris Payne on the manual, STOS programmers moved to AMOS). Issue 9, April 1990, p. 95: Jason Holborn’s AMOS preview (screens, sprites and bobs, double-buffering, AMAL, music). Issue 17, December 1990: Mandarin advertisement (25,000 copies, the AMOS Club, Sandra Sharkey’s PD library). Issue 26, September 1991, p. 114: AMOS Compiler review (RAMOS, stand-alone programs). Issue 27, October 1991: AMOS 3D advertised as “now available”.
Amiga Computing, August 1990, p. 8: “AMOS — The Creator is here” (Chris Payne, the manual, the included games, £49.99). November 1991: subscription offer (“over 40,000 users”, the compiler’s speed claims). March 1992: AMOS column on Easy AMOS and Mel Croucher’s manual. May 1992: Easy AMOS review. November 1992: Phil South’s AMOS Professional review (£69.99). December 1992: Europress advertisement for AMOS Professional (200 new commands, over 700 in total, Croucher and Stephen Hill). October and November 1993: AMOS Professional Compiler advertisements.
CU Amiga, August 1990: AMOS review (STOS as “the surprise ST hit of late 1988”, MOVE, the included games, “the days of the machine code programmer are numbered”) and the software chart.
ACE, issue 35, August 1990: AMOS review by Laurence Scotford (line numbers, the support programs, the “powerful toy”).
Amiga Shopper, issue 16, August 1992, and issue 17, September 1992: the official AMOS PD library passes from Sandra Sharkey to Len and Anne Tucker; Totally AMOS. Issue 18, October 1992: Sharkey continues her licenseware. Issue 28, August 1993: Jason Holborn on getting AMOS programs published, and Europress’s title-screen rule. Issue 34, February 1994: Lionet stops work on AMOS; Blitz Basic 2 and AGA. Issue 40, August 1994: Lionet’s first game. Issue 43, November 1994: AMOS column (Scorched Tanks, Xap, Jetstrike). Issue 45, January 1995, p. 87: AMOS column (Extreme Violence, disguising AMOS). Issue 57, Christmas 1995: “The life and times of AMOS” (STOS begun in 1986, military service, v1.1 on 12 June 1990), “AMOS makes a come-back” (Europress dropped AMOS in 1994; Ultimate Software), and “Disguising AMOS”.
AOZ Studio, “AMOS-Professional-Official”, GitHub repository README (web, secondary): the MIT licence and the public domain release of 1 December 2012. https://github.com/AOZ-Studio/AMOS-Professional-Official