Editing Atari ST (section)

=== ST/ST<sup>F</sup>/ST<sup>M</sup>/ST<sup>FM</sup> ===
As originally released in the 520ST:

* CPU: [[Motorola 68000]] 16-/32-bit CPU<ref "16/32">{{cite book | title = M68000 Family Programmer's Reference Manual | publisher = Motorola | year = 1992 | pages = 1 | isbn = 0-13-723289-6 }}</ref> @ 8&nbsp;[[Megahertz|MHz]]. 16-bit data/32-bit internal/24-bit address.
* RAM: 512&nbsp;KB or 1&nbsp;[[Megabyte|MB]]
* Display modes (60&nbsp;Hz NTSC, 50&nbsp;Hz PAL, 71.2&nbsp;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, monochrome
* Sound: [[General Instruments AY-3-8912|Yamaha YM2149]] 3-voice square wave plus 1-voice white noise mono [[Programmable Sound Generator]]
* Drive: Single-sided 3{{frac|1|2}}" [[floppy disk]] drive, 360&nbsp;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 color and mono, 13-pin [[DIN connector|DIN]]), extra disk drive port (14-pin [[DIN connector|DIN]]), [[Direct memory access|DMA]] port (ACSI port, Atari Computer System Interface) for [[hard disk]]s and Atari Laser Printer (sharing RAM with computer system), joystick and mouse ports (9-pin MSX standard)
* [[Operating System]]: [[Atari TOS|TOS]] v1.00 with [[Graphics Environment Manager]] (GEM)

Very early machines have the OS on a floppy disk before a final version was burned into ROM. This version of TOS was bootstrapped from a small core [[boot ROM]].

In 1986, most production models became ST<sup>F</sup>s, with an integrated single- (520STF) or double-sided (1040STF) double density floppy disk drive built-in, but no other changes. Also in 1986, the ''520ST<sup>M</sup>'' (or ''520STM'') added an [[RF modulator]] for allowing the low and medium resolution color modes when connected to a TV. Later ''F'' and ''FM'' models of the 520 had a built-in [[double-sided disk]] drive instead of a single-sided one.