Manufacturer

Atari (US)

Model

520 ST

Date Launched

January 1985 in US
Late 1985 in UK

Price

£700
In 1993 the price had dropped to £209.

Microprocessor type

Motorola 68000 @ 8 MHz

ROM size

192 kilobytes

Standard RAM

512 kilobytes

Maximum RAM

1024 kilobytes
2 megabytes on later STe model

Keyboard type

Typewriter style with separate numeric pad, cursor keys and function keys

Supplied language

Originally ST BASIC (loaded from disc).
Later models were supplied with the much better, compiled, 1STBASIC from HiSoft.

Text resolution

Selectable 40 X 25 or
80 x 25 characters

Graphics resolution

320 x 200, 640 x 200 or 640 x 400 pixels
640 x 400 mode required a special monochrome monitor, other two modes could be displayed on a domestic television.

Colours available

16 or 4 different colours on screen (at the two lower resolutions) from a palette of 512.
Monochrome at highest resolution.

Example Screenshot

The 320 x 200 pixel mode allowed reasonable resolution with 16 colours.
This is a page from an astronomy ephemeris program.

Sound

Three note polyphonic using AY-3-8910 chip, output through television

Cassette load speed

Used disc drives only

Dimensions (mm)
Weight (grams)

740 x 240 x 60
2100

Special features

Incorporated the GEM (Graphical Environment Manager) user interface in ROM.
This was an early and quite usable mouse and icon based system from Digital Research.

Good points

One of the fastest and best equipped desktop computers of the time, and at a reasonable price.
The GEM front-end was a vast improvement on the command-line based DOS used on most of its competitors.

Bad points

Being a completely new machine there was a delay before good software began to appear.
The machine was designed in only about 6 months and some features seemed rushed. It was difficult to access GEM using the supplied BASIC and GEM itself did not seem to make full use of the ST's graphics abilities.

How successful?

Very popular as a home computer but never made an impact in the business world.
With some improvements the ST range remained on sale until 1993 and in total around 4 million STs were sold.
Almost uniquely the ST had MIDI ports built-in, to connect to electronic musical instruments, and it created a niche for itself in music sequencing and small scale music recording.

Comments

The Atari ST was clearly designed to compete with the Apple Macintosh, offering similar capabilities at a lower price. The original model had an external floppy disc drive of 360 KB (single sided) or 720 KB (double sided) capacity. A matching monitor was available.

The later 520STFM and 520STe models incorporated a 3½ inch 720KB disc drive into the right hand side of the case, which was slightly deeper. Although the ST was leading edge when it was launched, Atari did not seem to develop either the hardware or the user interface enough to keep up with IBM PC types and by the early 1990s the ST range was looking old. In 1993 a greatly improved version of the ST known as the Falcon was launched.