Atari ST

An Atari 1040STF computer with keyboard, mouse, and Atari SC1224 color monitor, the GEM desktop visible on screen

Atari 1040STF system photo: Bill Bertram, CC BY-SA 2.5, via Wikimedia Commons.

The Atari ST family — launched in 1985, and extended by the Atari STE in 1989 — paired a Motorola 68000 with a dedicated graphics/sound chip (the Shifter, later joined by STE's DMA sound and blitter) at a price that undercut the Macintosh and the Amiga alike. Like the Amiga, it drew a real community of paint, drawing, and animation software around it, much of it built on the ST's own low-resolution, 4-bitplane, 16-color screen mode.

Atari ST File Formats

The ST's fixed screen modes — low-resolution 320×200 at 4 bitplanes chief among them — gave every paint and animation program on the platform the same starting point, but GEM/TOS never had a shared container format the way IFF gave the Amiga one. DEGAS, NEO, Cyber Paint, and the rest each rolled their own file layout instead, almost always keyed directly to that same 320×200×16 geometry underneath. What's below is what survives of that decade of ST-native paint and animation software: still opened today by ST demoscene preservationists, emulator users, and retro-computing archivists digging up old disks.

Formats on This Page

FormatExtensionKindIntroduced
DEGAS & DEGAS Elite.pi1–.pi3, .pc1–.pc3Bitmap1985 / 1986
NEOchrome.neo, .aniBitmap & animation1985 / 1986
Cyber Paint (CEL & SEQ).cel, .seqBitmap & animation1987
Spectrum 512.spu, .spc, .sps, .pcsBitmap (truecolor)1987

Cyber Paint — CEL and SEQ

Cyber Paint was Jim Kent's paint-and-animation program for the Atari ST, published by Antic Software. It saved individual frames as CEL files and full animations as SEQ ("sequence") files, the latter built around a delta-compression scheme fast enough to play back full-motion animation straight off a floppy disk.

AspectDetail
DeveloperJim Kent
PublisherAntic Software (Antic Publishing)
ReleasedVersion 1.0, 1987; Version 2.0, Summer 1988
PlatformAtari ST and STE
Related programCould load and edit animations from Cyber Studio (Tom Hudson's CAD-3D 2.0 bundled with Mark Kimball's Cybermate), whose own DLT delta format Cyber Paint's SEQ format improved on
Extensions.cel (Cyber Paint Cell), .seq (Cyber Paint Sequence)

History

Jim Kent had already written the delta-compression technique behind the Amiga ANIM format's Op 5 method, for Aegis Animator in 1985, and ported Aegis Animator itself to the Atari ST. His next ST program, Flicker — a simple flipbook animation utility, built in about a week — caught the attention of Gary Yost, who ran Antic's software-publishing arm and arranged for Flicker to run in Antic's START magazine.

Antic had separately published Tom Hudson's Cyber Studio CAD-3D, a 3D modeling and animation package, in 1986; a year later, CAD-3D 2.0 was bundled with Mark Kimball's Forth-based Cybermate authoring language as "Cyber Studio." Cybermate stored its animations as an external DEGAS base picture plus a chain of raw EOR-delta frames — the DLT format. Kent studied that delta technique and realized it could power a full 2D paint-and-animation program of its own, not just script CAD-3D renders. The result, Cyber Paint, stood on its own as a paint and animation tool and could also load and "doctor" Cyber Studio's own animations.

Cyber Paint shipped as Antic Software Version 1.0 in 1987; Version 2.0 followed in the Summer 1988 wave of Cyber-branded software, one of the last releases before Gary Yost left Antic to found the Yost Group. There, Kent carried the same delta-animation ideas into Autodesk Animator (1989) and Animator Pro (1991) for MS-DOS — direct evolutions of Cyber Paint, licensed to and published by Autodesk. Kent's own authorship stopped there: a Windows successor did eventually ship, Animator Studio in 1995, but as a ground-up rewrite for Windows 95 no longer developed by the Yost Group.

Cyber Paint's own SEQ format improved on Cybermate's DLT scheme: rather than storing whole-screen EOR deltas, it splits the screen into its four ST bitplanes and run-length compresses each one vertically, roughly doubling storage density while still decompressing faster than the data could be streamed off a floppy disk in the first place.

Legacy and Popularity Today

Neither format was ever formally documented outside Atari retro-computing circles — what survives is mostly community reverse-engineering and archive listings like AtariMania's. Original Cyber Paint animations still circulate among ST demoscene and animation preservationists; Jim Kent's own "Tesla" demo animation, made in Cyber Paint, is archived today on Werner Randelshofer's Atari animation collection. Kent himself left games behind for computational biology, becoming a researcher at UC Santa Cruz where he wrote BLAT and created the UCSC Genome Browser — the same career turn noted on this site's Amiga page, since it was the same delta-animation work, on two different machines, that led there.

Paintapp Support

Paintapp reads Cyber Paint Cell files as a single uncompressed Atari ST low-resolution (4-bitplane, 16-color) frame. Width and height are explicit in the header rather than assumed, so non-standard cell sizes are read correctly alongside full 320×200 screens, and both classic ST (3-bit RGB) and STE (4-bit) palette encodings are auto-detected.

Paintapp plays back Cyber Paint Sequence animations, including per-frame palette changes for color-cycling effects.

Links

DEGAS and DEGAS Elite

DEGAS was the Atari ST's first serious paint program, and by early 1987 a contemporary magazine review was calling it the platform's best-selling software, full stop — not just best-selling paint program.

AspectDetail
DeveloperTom Hudson (working title: "HUDraw")
PublisherBatteries Included, Richmond Hill, Ontario, Canada
DEGAS released1985
DEGAS Elite released1986 — list price $79.95, or a $40 upgrade with the original DEGAS disk traded in
Extensions.pi1, .pi2, .pi3 (uncompressed); .pc1, .pc2, .pc3 (PackBits-compressed, DEGAS Elite)

History

Tom Hudson — the same programmer behind Cyber Studio's CAD-3D, above — wrote DEGAS for Batteries Included in 1985, shortly after the ST itself launched. DEGAS Elite followed in 1986, adding PackBits compression to shrink picture files, plus color-cycling animation data that could be saved right alongside a still picture in the same file.

Legacy and Popularity Today

"DEGAS has been the biggest-selling ST program to date," Antic magazine wrote in January 1987 — a striking claim for a paint program to hold against every other category of software on the machine, games included. Its chief rival for ST artists was NEOchrome, below, which had the advantage of shipping free with every ST. DEGAS pictures are still widely readable today: the actively maintained pixel-art editor GrafX2 loads and saves them natively, and XnView can open them with its full format list enabled.

Paintapp Support

Paintapp reads both plain and PackBits-compressed DEGAS pictures, across all three ST screen resolutions (low-res 16-color, medium-res 4-color, high-res monochrome), and a rare non-standard 320×280 low-res variant. DEGAS Elite's color-cycling animation ranges, when present, are read as well.

Links

NEOchrome

NEOchrome was Atari's own paint program, bundled free on the system disk of every ST rather than sold as separate software — most ST owners' first paint program, whether or not it stayed their favorite.

AspectDetail
DeveloperDave Staugas, with programmer Jim Eisenstein and interface designer Jerome Domurat — all at Atari Corporation
PublisherAtari Corporation — bundled with every ST, never sold separately
ReleasedAn early v0.5 build shipped on the first STs' system disks in 1985; v1.0 was shown publicly at London's PCW Show in 1986
Companion formatNEOchrome Animation (.ani), added from v0.9 — borrows its palette from a sibling .neo screen rather than storing its own
Extensions.neo (NEOchrome), .ani (NEOchrome Animation)

History

Dave Staugas, one of the programmers behind the ST's own TOS operating system, wrote NEOchrome together with programmer Jim Eisenstein and interface designer Jerome Domurat — who also drew the ST's system icons and fonts. An early v0.5 build was already on the system disks of the very first STs in 1985; NEOchrome reached version 1.0 and was demonstrated publicly at London's PCW Show in 1986. Atari never sold it as a separate product — it was simply part of what came with the machine.

From version 0.9 onward, NEOchrome could record its own animations too, saving them as a companion .ANI file alongside a NEOchrome screen. The .ANI format carries no palette of its own — it borrows the colors of whichever .NEO screen it was recorded against.

Legacy and Popularity Today

Because NEOchrome came free with every ST, it stayed popular within the ST community "even in the face of more advanced packages such as DEGAS and Deluxe Paint," as Wikipedia describes it. A fan-made successor, NEOchrome Master, followed in 1992 from Chaos Inc./The Delta Force — crediting Tillman Bubeck alongside the original Staugas/Eisenstein/Domurat team — adding STE and Blitter support, multiple work-screens, and the ability to import DEGAS, IFF, and Doodle pictures alongside NEOchrome's own. Original NEOchrome releases and their file format are still catalogued today by retro-computing archives and demoscene sites like Demozoo.

Paintapp Support

Paintapp reads NEOchrome pictures — the fixed-size low, medium, or high-resolution ST screen, its 16-color palette, and a color-cycling animation range when the file defines one — and plays back NEOchrome Animation clips, reading their palette from a companion .NEO file when one is present alongside it.

Links

Spectrum 512

Spectrum 512 pushed the ST's 16-color hardware far past its intended limit, reprogramming the palette registers mid-scanline to put up to 512 different colors on screen at once — a genuine hardware trick, built into a paint program rather than just a file format.

AspectDetail
DeveloperBoris Tsikanovsky, of Trio Engineering Inc. (founded with his brother Michael Elman)
PublisherAntic Software (Antic Publishing) — contract signed spring 1987
Released1987
How it worksThe palette is reloaded up to three times per scanline, each reload drawing from the same 512-color universe (8 levels per RGB channel) — so one 320-pixel line can show up to 48 colors chosen from the full 512
Companion productsDigiSpec (video digitizer capture), UniSpec
Extensions.spu (uncompressed), .spc (compressed), .sps ("smooshed", heavier compression)

History

Boris Tsikanovsky got an Atari ST in 1986 and built the palette-cycling engine behind Spectrum 512 at Trio Engineering, the Massachusetts company he had founded with his brother Michael Elman. Antic Software signed the pair in spring 1987 and published Spectrum 512 that year, squeezing far more color out of the ST than Atari's own 16-color limit implied was possible, by reprogramming the palette registers between pixels rather than once per frame.

Legacy and Popularity Today

ST-Log's August 1988 review said Trio Engineering had "taken the ST to limits of color display never attained before," and UK magazines agreed — Amiga/ST Format gave it 4 out of 5 that same year. Steve Belczyk documented the format's decoder publicly in December 1990. Modern support is mixed: GrafX2, which reads DEGAS and NEOchrome natively, doesn't support Spectrum 512, though period tools and dedicated ST image viewers still do. Atari-Forum hobbyists were still extending the format as recently as the 2020s, pushing an uncompressed .SPU variant to 32,768 colors.

Paintapp Support

Paintapp decodes all three Spectrum 512 picture variants — uncompressed .SPU, PackBits-compressed .SPC, and the more heavily compressed "smooshed" .SPS — reconstructing the full per-scanline palette trick into a plain truecolor image.

The same reader also handles PhotoChrome (.PCS), a later, separate program that pushes the same idea further: two full frames, each with the palette trick applied, blended together into one image for an even wider effective color range. Paintapp decodes both single- and dual-frame PhotoChrome files, including their optional XOR delta-coding between frames, and both classic ST and STE palette encodings throughout.

Links

See Also