Mine was the Atari 400 (Information and images taken from www.old-computers.com and www.vintage-computer.com)
The Atari 400 and 800 were the first home computers to use custom coprocessors and the first to use "sprites" and special video interruptions like display lists; features that would be implemented later on the Commodore 64, then on the Commodore Amiga (Atari 400/800 and Amiga were both designed by Jay Miner).
It offered high graphic resolution, lots of colors and great sound capabilities, more than other computers could do then! The two models had same characteristics, but the 800 had 48 KB of RAM (instead of 16 kb), two cartridge ports (only one for the 400) and a proper mechanical keyboard (a membrane keyboard for the 400).
In fact the very first Atari 800 Computers were shipped with 8 or 16 KB memory, expandable to 48 KB. After initial release, the 800 came standard with 48 KB memory.
Game Screenshot
Prior to production, the 800 was known inside Atari as code name "Colleen". It is rumored that Colleen and Candy (the 400 code name) were actually secretaries at Atari.
Released: 1979
Ended production: 1982
Input: QWERTY full Stroke keyboard, 62 keys and 4 function keys (Reset, Option, Select, Start)
CPU: 6502 @ 1.79 Mhz
CO-PROCESSOR ANTIC (Scrolling, Sprites, Video), CTIA / GTIA (Color, Sprites, Collisions), POKEY (timers, sound, keyboard, serial I/O), PIA 6810 (I/O, including the 4 joystick ports)
RAM: 8 KB to 48 KB (with memory expansion boards)
ROM: 10 KB
TEXT MODES: 40 x 25
GRAPHIC MODES: several graphic modes, maximum : 320 x 192
COLORS: 16 (each color can have 8 luminances) = 128 colors maximum in the lowest graphic mode (requiring display list interruption to have them simultaneously)
and up to 256 colors in some specific modes for machines having the GTIA chip instead of the CTIA
SOUND: 4 voices, 3.5 octaves
I later upgraded to the Atari 800
Then it was the Atari ST 520
The 520 ST featured same hardware basis and same amount of memory as the 260 ST.
The main difference between them was the built-in ROM TOS operating system and GEM Graphics Interface. In fact, the Atari 520ST originaly came with the OS on floppy as the OS was not completly finished. Very shortly afterward they came with the OS on 6 ROM chips (TOS 1.0).
It was first sold in Germany where it met a great success then released in the United States about six monts later. Colour and monochrome version were available. Sadly, users of the colour version couldn't expect programs written for the monochrome version to work until someone wrote an emulator allowing the software written for the monochrome version to run on a colour monitor.
Atari was the first company to offer built-in MIDI ports. This made the computer very popular with musicians. One game even used the MIDI conectors (Midi Maze) to connect up to 16 computers together in a MIDI network.
The 520 ST+ offered 1 MB of RAM instead of 512 KB. As the main board was designed to provide space for only 512 KB of RAM (16 x 41256 type chips), the second 512 KB bank chips were soldered on top of the original chips.
Apparently, 1 Mb versions were sold as Atari 1040s in Australia...
The model 520 STM came with a built-in TV modulator allowing a direct connection with the TV-set.
The original Atari 520 ST came with an external 360K single sided 3.5 floppy drive, the SF354. Most dealers either bundled it with separate power supply, or a much neater Cumana or Triangle branded drive at lower cost.
NAME 520 ST / ST+ / STM
MANUFACTURER Atari
YEAR 1985
KEYBOARD: Full-stroke keyboard with numeric and editing keypads
CPU: Motorola MC68000
SPEED: 8 mHz
CO-PROCESSOR: 'Shifter' and 'Glue' custom chips
RAM: 512 KB (520 ST/STM), 1 MB (520 ST+)
ROM: 192 KB
TEXT MODES: 40 or 80 columns x 25 lines
GRAPHIC MODES: 320 x 200 / 640 x 200 / 640 x 400 dots
COLORS: 16 among 512 (320 x 200) / 4 among 512 (640 x 200) / monochrome (640 x 400) this last mode needs a special monitor.
SOUND 3 voices, 8 octaves
I/O PORTS: RGB, TV modulator (520STm), Cardridge, Midi (in/out), Centronics, RS232c, Hard Disk, Floppy Disk, Joystick, Mouse
BUILT IN MEDIA: External 3.5'' 360 KB disk-drive (option)
OS: TOS / GEM
After that it was PC's all the way.
A Video showing screenshots and playing original atari ST music from my favourite game. Blood Money.
http://www.youtube.com/watch?v=AcFSpbZO-g8
