In 1985 Atari Corporation introduced its new 16-bit computer system.   Called the 520ST.   520 being the memory size and ST for Sixteen/Thirty Two bit processor.   The Atari ST originally had its OS delivered on floppy disk since the OS ROM's were not ready for shipping.   The 520ST represents a major step forward in computer design and OS design.   However many rough spots do show through and this most likely is a result of the machine being rushed market to gain a lead on the soon to be release Amiga computer system which was bought by Commodore and the money that Atari had been supplying to Amiga for development to use the technology in the Atari 1850XL computer before the Tramiels bought Atari was paid back.    The ST computer utilized the Digital Research GEM interface for a graphics environment.   (As an interesting note, Apple Computer sued Digital Research for the GEM "Look & Feel" on the PC version and Digital Research was forced to change it, how Apple never sued Atari or Digital for the version used on the Atari ST's.   Perhaps Apple felt that the Atari ST's were not going to be a enough of a threat to merit a lawsuit.)
 
 
 

Architecture Processor CPU: Motorola 68000 Running at 8 Mhz Memory RAM 512K ROM up to 192K Cartridge 128K external Storage Floppy-Standard 3.5inch Floppy Disk via DMA Drive Capacity: 360K 2nd Drive Optional Hard Disk DMA Interface built-in Data Transfer: 1.33Mbps Graphics/Video Bitmapped Monocrome 640X400 Sync: Seperate 5vdc, 3.3k ohm Horizontal: 35.7 Khz Vertical: 71.2 Hz Color 640X200 X 4 Color 320X200 X 16 Color Pallette size: 512 Colors Video: RGB Sync: 5vdc, 3.3k ohm Horizontal: 15.75 Khz Vertical 60 hz

User Interface Keyboard Standard QWERTY Seperate Numeric Keypad and cursor cluster Mouse 2-button control High precision, non-slip motion-sensor Sound 3 programmable sound channels Frequency 30Hz to 125 Khz Dynamic envelope shaping Audio out 1.0v peak to peak 10K ohm Input/Output Printer Industry Standard Parallel 23 pin D-type connector Modem RS-232-C Standard (DTE) 50-19,200 Baud 25 Pin D-type connector MIDI (Musical Instrument Digital Interface) 2 Ports: MIDI IN, MIDI OUT/THROUGH 31.25K baud Optically isolated receiver 5 pin din connectors Operating System TOS with GEM Environment Hierarchical filing with sub-directories and path names User interface via GEM with self-explanitory command functions Icons, Multi-Windowing Drop-down menus GEM virtual device interface