Atari 520ST, STm
Atari 520STm
I have two 520ST and four 520STm (one STm CIB) main units, many Mice,
many Joysticks, five Power Adapters, four Atari sf314 Disk Drives (one CIB),
three Atari sf354 Disk Drive, four Disk Power Adapters and four Disk Cables.
type computer
country USA
year 1985 (ST) / 1986 (STm)
os TOS 0.89-1.00 (disk or rom), GEM -desktop
cpu Motorola MC68000
speed 8 MHz
ram 512 KB
rom 192 KB
graphic 320×200 (16)
colors 512
sound 3 voices, 8 octaves
ports RGB, TV modulator (520STm), Cardridge, Midi (in/out), Centronics, RS232c, Hard Disk, Floppy Disk, Joystick, Mouse
The Atari 520ST — The Original ST
Released in June 1985, the Atari 520ST was the original model in the ST family — the machine that launched Jack Tramiel’s comeback and saved Atari Corporation from oblivion. Developed in just five months by a team of engineers led by Shiraz Shivji, the 520ST offered a 8 MHz Motorola 68000 processor, 512 KB of RAM, a colour graphical interface (GEM desktop), and built-in MIDI ports at a price of $799 — dramatically cheaper than the Apple Macintosh ($2,495) and competitive with the Commodore Amiga. It sold over 50,000 units in its first six months, immediately establishing the ST as a major player in the home computer market.
Faster Than Expected Development
The 520ST’s five-month development timeline from conception to consumer product was extraordinary — and it showed in some rough edges of the initial design. Early machines lacked a built-in floppy drive (an external drive was required), TOS was initially loaded from floppy rather than ROM, and various software compatibility issues affected early units. These problems were addressed in subsequent revisions, but the 520ST’s rushed development became something of a legend in computing history — an example of what a determined team could achieve under extreme time pressure.
The ST’s Graphical Interface
The ST’s GEM (Graphical Environment Manager) desktop, licensed from Digital Research, gave users a Mac-like point-and-click interface at a consumer price point. Colourful, accessible, and reasonably intuitive, GEM made the ST genuinely approachable for non-technical users while providing a capable environment for professional applications. The combination of GEM, the 68000 processor, and the ST’s built-in MIDI ports made it particularly popular among musicians, graphic artists, and desktop publishers throughout Europe.