History of the Atari ST's:
Some prototypes were never sold - an Atari 130 ST (with just 128KB RAM).
The first model for the masses was the Atari 520 ST:
- Motorola 68000 @ 8 MHz 16 bit data/24-bit external address
- 512 KB or
- 1024 KB
Display modes (60 Hz NTSC, 50 Hz PAL, 71.2 Hz monochrome):
- Low resolution - 320×200 16-colors, out of a palette of 512 colors
- Medium resolution - 640×200 4-color, out of a palette of 512 colors
- High resolution - 640×400 monochrome
- Yamaha YM2149
- SS 3½" floppy disk drive, 360 KB capacity
- DD 3½" floppy disk drive, 720 KB capacity
- TV out (on "M" models, RF modulated)
- MIDI in/out
- RS-232 serial
- Centronics parallel
- 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
- Joystick and mouse ports (9-pin MSX standard)
An external/separated floppy drive SF354 (SS/DD) and SF314 (DS/DD) was sold as a companion for the above mentioned 520 ST.
last but not least, a real famous monitor model appeared also - the SM124:
Later (in 1986) a ST appeared with an integrated floppy - the Atari 1040 STF.
Although it was almost the same hardware, it offered 1024 KB RAM and the already mentioned DS/DD 3.5" floppy drive.
A downgraded 520STFM was also selled. The "M" means "Modulator" and in fact these models have a RF jack for TV usage, too.
Also, a harddisk named SH204 (in a metal case, as an exception) was sold.
Also, a series with detached keyboard were made - Mega ST 1 to 4.
Harddisks were offered with similar cases (SH205 and Megafile series).
In 1989, a new series with some enhancements (larger color palette, Blitter) was born - the STE series. The 512STE and 1040STE were offered in similar cases (like their predecessors). The MEGA STE finally came in a TT-case and an integrated harddisk, and a slightly improved detached keyboard (from all ST keyboards, I only like this one). This was the fastest ST with a 68000 CPU @ 16MHz.
At the moment, I will not focus my pages on successor models like TT or Falcon.