Atari ST520 with color monitor


  • Released: June 1985
  • Type: Home computer
  • Introductory price: US$799.99 (monochrome monitor), US$999.99 (color monitor)
  • Manufacturer: Atari
  • CPU: Motorola 68000 @ 8 MHz
  • Memory: 512 KB
  • OS: Atari TOS/GEM (Digital Research)
  • Discontinued: 1993
  • Model: 520 ST
  • ROM: 192 KB
  • Built in media: 3.5" 360 KB diskdrive (external)
  • Predecessor: Atari 8-bit family
  • Graphic: 320 x 200 / 640 x 200 / 640 x 400 pixels
  • Colors: 16 of 512 (320 x 200) / 4 of 512 (640 x 200) / monochrome (640 x 400 - special monitor)
  • Sound: 3 voices, 8 octaves
  • I/O ports: RGB, Cardridge, MIDI, Centronics, RS232c, Hard Disk, Floppy drive, Joystick, Mouse

Released 1985: The Atari ST is a line of home computers from Atari Corporation and the successor to the Atari 8-bit family. The initial ST model, the 520ST, saw limited release in April-June 1985 and was widely available in July. The Atari ST is the first personal computer to come with a bitmapped color GUI, using a version of Digital Research’s GEM released in February 1985.

The Atari ST is part of a mid-1980s generation of home computers that have 16 or 32-bit processors, 256 KB or more of RAM, and mouse-controlled graphical user interfaces. It includes the Macintosh, Commodore Amiga, Apple IIGS, and, in certain markets, the Acorn Archimedes. “ST” officially stands for “Sixteen/Thirty-two”, which refers to the Motorola 68000’s 16-bit external bus and 32-bit internals.

My Atari ST520: I got it together with a lot of Commodore 64’s, it was complete with mouse, external floppy drive and a power supply. However, it was really dirty and didn’t worked when power on. I took the ST apart, including all the key caps and gave them a good clean. Inside, it had a 3rd part memory expansion that was “piggy back” type and some clamps for currents. It all had loosened. Once I fitted it correctly, the computer worked.

Next, the floppy drive was just spinning and refused to load any floppies. Once opened, I spotted the drive belt had melted/snapped. I found a rubber band as an replacement to temporary test if that was it. I succeeded loading the game “OutRun”. I then found a proper belt replacement on Internet.

Atari ST520

Remi Jakobsen

I'm collecting classic computers and video games, stretching from the 70's into the 90's. Restoration, history, usage ...

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