Back to: Atari

Atari ST models

Atari ST original setup
CPU: Motorola 68000 16-/32-Bit CPU[22] @ 8 MHz. 16 bit data/32 bit internal/24-bit address.
RAM: 512 kB or 1 MB
Display modes (60 Hz NTSC, 50 Hz PAL, 71.2 Hz monochrome):
    Low resolution - 320×200 (16 color), palette of 512 colors
    Medium resolution - 640×200 (4 color), palette of 512 colors
    High resolution - 640×400 (mono), monochrome Sound: Yamaha YM2149 3-voice squarewave plus 1-voice white noise mono Programmable Sound Generator
Drive: Single-sided 3½" floppy disk drive, 360 kB capacity when formatted to standard 9 sector, 80 track layout.
Ports: TV out (on ST-M and ST-FM models, NTSC or PAL standard RF modulated), MIDI in/out (with 'out-thru'), RS-232 serial, Centronics parallel (printer), monitor (RGB or Composite Video colour and mono, 13-pin DIN), extra disk drive port (15-pin DIN), DMA port (ACSI port, Atari Computer System Interface) for hard disks and Atari Laser Printer (sharing RAM with computer system), joystick and mouse ports (9-pin MSX standard)
Operating System: TOS v1.00 (The Operating System) with the Graphical Environment Manager (GEM)

Atari STe
All of the features of the 520STFM/1040STFM
Extended palette of 4,096 available colours to choose from
BLiTTER chip for copy/fill/clear large data blocks in memory (fill rate 4 MB/s)
Hardware-support for horizontal and vertical fine scrolling and split screen (using the Shifter video chip)
DMA sound chip with 2-channels stereo 8-bit PCM sound at 6.25/12.5/25/50 kHz and stereo RCA audio-out jacks (using enhancements to the Shifter video chip to support audio shifting)
National LMC 1992 audio controller chip, allowing adjustable left/right/master volume and bass and treble EQ via a "Microwire" (3-bit serial) interface
Memory: 30-pin SIMM memory slots (SIPP packages in earliest versions) allowing upgrades up to 4 MB Allowable memory sizes including only 0.5, 1.0, 2.0, 2.5 and 4.0 MB due to configuration restraints
(however, 2.5 MB is not officially supported and has compatibility problems). Later 3rd-party upgrade kits allow a maximum of 14MB w/Magnum-ST, bypassing the stock MMU with a replacement unit and the additional chips on a separate board fitting over it.
Ability to synchronise the video-timings with an external device so that a video Genlock device can be used without having to make any modifications to computer's hardware
Analogue joypad ports (2), with support for devices such as paddles and light pens in addition to joysticks/joypads. The Atari Jaguar joypads and Power Pad joypads (gray version of Jaguar joypads marketed for the STE and Falcon) can be used without an adapter. Two standard Atari-style digital joysticks could be plugged into each analogue port with an adapter.
TOS 1.06 (also known as TOS 1.6) or TOS 1.62 (which fixed some major backwards-compatibility bugs in TOS 1.6) in two socketed 128 kB ROM chips.
Socketed PLCC 68000 CPU Models The members of the ST family are listed below: 520ST

Models The ST family:
520ST
Original model with 512 kB RAM, external power supply, no floppy disk drive. The early models had only a bootstrap ROM and TOS had to be loaded from disk.

130ST
intended to be a 128 kB variant. Announced at the 1985 CES alongside the 520ST but never produced.

520ST+
early 520STs with 1 MB of RAM, but without floppy disk

260ST
originally intended to be a 256 kB variant, but actually sold in small quantities in Europe with 512 kB. Used after the release of the 520ST+ to differentiate the cheaper 512 kB models from the 1 MB models

520STM
a 520ST with a built-in modulator for TV output, 512 kB RAM.

520STFM
a 520STM with a newly redesigned motherboard in a larger case with a built-in floppy disk drive (in some cases a single sided drive only), 512 kB RAM.

1040STF
a 520STFM with 1 MB of RAM and a built-in double-sided floppy disk, but without RF modulator

1040STFM
a 520STFM with 1 MB of RAM and a built-in double-sided floppy disk with RF modulator

Mega ST
(MEGA 1, MEGA 2, MEGA 4) redesigned motherboard with 1, 2 or 4 MB of RAM, respectively, in a much improved "pizza box" case with a detached keyboard. All MEGA mainboard have a PLCC socket for the Blitter chip and some early models did not include the BLiTTER chip. Included a real-time clock and internal expansion connector. Some early MEGA 2 had a MEGA 4 mainboard with half of the mem chip places unpopulated and these MEGA 2 can be upgraded by adding the additional DRAM chips and some resistors for the control lines. The MEGA 1 mainboards had a redesigned mem chip area and could not be upgraded in this way as there are only mem chip places for the 1 MByte DRAM chips.

520STE and 1040STE
a 520STFM/1040STFM with enhanced sound, the BLiTTER chip, and a 4096-color palette, in the older 1040 style all-in-one case