Task: Purchase an Atari ST
Needed: Atari 520 ST, Power Supply, Monitor, Mouse
Time: 30-60 minutes
Introduction
I grew up with Atari 8-bit computers in the early to mid-1980s but missed their next generation systems as I jumped to PC as many did at the time. Atari released the 520 ST in 1985 featuring a Motorola 68000 CPU and 512K of RAM and competed head-to-head with Macintosh released in 1984 and the Amiga 1000 released in 1985. Thus, the 520 ST is indeed a piece of computing history.
The 520 ST featured the 68000 processor that had a 32-bit instruction set, 24-bit address bus, and 16-bit data bus. Even though it could address more memory, the system was limited to 4MB maximum due to the memory management unit (MMU).
The ST featured “The Operating System” or TOS with a GUI called the Graphics Environment Manager or GEM.
The ST series is best known for its MIDI port that was popular with musicians.
Note that some 520 STs come with floppy drives and the STF designation.
I picked up my Atari 520 ST years ago at a flea market. I had a note on it that said it did not boot. I recently cracked open the case to see what kind of repair might be needed and discovered it had a 512KB memory upgrade board from Tech-Specialties sitting on top of the mother board (see second photo below) giving the machine a total of 1MB RAM. Pressing on this RAM board got the system to boot. I ended up putting a piece of IC foam in between the board and the keyboard to put some additional downward pressure on the MMU chip to maintain contact.
Instructions
The best place to look for 520 STs is eBay. Working units run about $250 to $300. Note that you will need an external power supply. I am using my original brick but have a newly made PSU on order from Keelog. You will also need a mouse and way to connect to a modern display. As you can see in the photo above, I also have a nice Atari SC1224 color monitor I can use. However, I ordered an RGB to SCART to use with my SCART to HDMI converter that works quite well with my Amigas. I will do a separate post on this video output method when they come in.
Comments
In addition to safe power and video conversion, a key challenge is how to get software onto the machine to be able play games, etc. Fortunately, there are several hard drive emulators available. I had some success with the Ultrasatan shown below booting into EmuTOS OS. I also have on order a new ACSI hard drive emulator that I am looking forward to trying. I will do separate posts on how to get these working. It is all a little confusing TBH.
