Atari ST

Vital Statistics

Introduced 1985
Retired: 1993
Price: £799, $600 (520ST), $999 (1040STF)
Quantity Sold: -
Countries: Worldwide
Dimensions: -
Weight: -
CPU: Motorola 68000 (8 MHz)
Ports: Centronics printer port, RS232C serial, MIDI in/out, RF out (STM/STFM/STE only), RGB video out
Usable RAM: 512K (520ST/STFM/STE), 1Mb (1040STF/STE/MEGA), 2Mb or 4Mb (MEGA)
Built-in ROM: Up to 192K + 128K in external cartridge
Colours: 16 colours from a palette of 512 (ST/STFM) or 4096 (STE)
Graphics: 640x400 (mono), 640x200 (4-colour), 320x200 (16-colour)
Sound: 3 programmable channels (ST and STfm) , PCM Stereo (STe)
Built-in Language: Atari BASIC (Revision B or C)
Built-in OS: TOS with GEM window environment
Other names : -

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What's it like today?

Fun Factor:
: Very Common (520STFM) to Very Rare (STacy and Falcon030)
Typical value: £30 (520ST)
Boxed & Mint: £80 (520ST)


In January 1985 Atari Corporation introduced its new 16-bit computer system, called the 520ST at the Winter Consumer Electronics Show in Las Vegas. "520" being the memory size and "ST" for Sixteen/Thirty-two bit processor. At release, two versions were available: the 520 with 512Kb RAM. Other cut-down versions were considered, including the 130ST (128K RAM) and 260ST (256K RAM), but Atari soon realised that after the operating system was loaded from floppy into RAM it left little to no room left for applications to run (eventually, the TOS operating system would take up 206K of RAM). The 260ST did make its way to Europe in limited quantities before being shelved.

The ST systems came with a single-sided external 3.5" floppy drive (these days quite a rarity!) and were bundled with TOS (The Operating System) which provided a graphical user interface similar to the Apple Macintosh. Due to the computer's simple design, Atari were able to release the 520ST two months before Commodore managed to get their new Amiga onto store shelves. Atari STs were sold with either a monochrome or colour monitor, with the monochrome supporting resolutions of 640x400. For colour, the ST supported two resolutions: 320x200 with 16 out of 512 colours, and 640x200 with 4 colours. The attached monitor determined which resolutions were made available to the computer when running software.

Initially new units were shipped to developers, the press, and certain user groups only, but finally released to the retail market in July 1985. Atari had built the new computer from concept to retail sale in just under a year - quite a record, even by today's standards. The first units came with TOS on floppy disk, but within a few months TOS was installed on a ROM chip inside the unit and automatically booted into it on startup. By late 1985, all new Atari STs came with an RF modulator - these were denoted as the Atari STM.

Technically, the Atari ST came with just a simple frame buffer and a 3-voice synthesizer chip, but fully supported the MIDI standard which meant the machine enjoyed success with customers wanting to run music sequencing software and as a direct controller for musical instruments. There was no support for hardware sprites, and didn't come with a battery-backed clock so the date and time had to be input on startup. it did come with an RS-232 serial port, Centronics parallel port, two joystick/mouse ports, two MIDI ports, a monitor port, ACSI hard disk port, floppy disk drive port and an ST cartridge port.

In 1986, Atari launched their upgraded ST, the 1040STF. This was largely the same as the 520ST, but came with 1 MB of RAM, the power supply was moved and a double-sided 3.5" floppy drive was integrated into the rear of the computer housing, similar to the Commodore Amiga. Without the 'M' in the model name, the 1040STF didn't come with the RF modulator, so a monitor was required. At the same time the 520ST was replaced with the 520STFM. This had 512K of RAM, and came with the modulator.

Shortly after, the MEGA was launched. Initially branded the ST1 and showcased at Comdex in 1986, the MEGA included a high quality external keyboard, a stronger case to support the weight of a monitor and an internal bus expansion connector. This expansion bus was later used by Atari's SLM804 laser printer, which used the attached MEGA's CPU and memory. This meant the printer itself was very economical to buy (the primary market for the MEGA was small businesses and for desktop publishing work).

The MEGA came in 2MB and 4MB variants, and a 1MB variant was released later.



In 1989, the 520STE and 1040STE models were launched - the 'E' standard for 'Enhanced'. These included better multimedia hardware and an upgraded operating system. The colour palette was increased from 512 colours to 4096, Genlock support and a graphics co-processor "Blitter" chip which could quickly move blocks of data around in RAM.

Also the 'E' models included a new 2-channel digital sound chip that could play 8 stereo samples in hardware at up to 50 kHz. Furthermore, the two joystick ports were replaced with 'Enhanced Joystick Ports' - still pin-compatible with the older joystick port with an adapter, these were to be used later on the Atari Jaguar, and are fully compatible.

The memory sockets inside the STE now supported SIMM modules for greater compatibility. Aside from these changes, however, the STE still ran at the same 8 MHz as the original ST. All STE machines reverted to the original integral case design of the STF/STFM, with integrated floppy drive.



A MEGA STE was to be the final STE machine released. This came in the new Atari TT grey case with a switchable 16 MHz mode, floating point co-processor, VME expansion slot, a network port and optional 3.5" hard disk drive.

The MEGA STE shipped with TOS 2.00, which had better support for hard disk drives, an enhanced desktop interface, memory test, 1.44 MB floppy drive support, and some bug fixes).



In 1990, Atari released a high-end workstation variant of the ST, called the TT030. This made use of the newer Motorola 68030 CPU which was fully 32-bit, and ran at 32 MHz. The TT featured improved graphics and more powerful support chips, and came in a completely redesigned case which supported an integral hard disk drive.


Atari ceased production of the ST/TT line of computers in 1993, when focus shifted to the Jaguar console.




This page was last updated on 31st August 2014.