The Atari 850 interface was probably the single most useful peripheral
Atari ever created for its computer systems. The Atari
850 gave the original Atari 400/800 and the last XL and XE systems their
"Eyes & Ears" so to speak. The Atari 850 interface
provided 4 separate RS-232-C serials ports addressed as devices R1: to
R4: and a single Centronics compatible printer port.
This allowed the Atari computers to use industry standard modems, terminal,
teletypes and printers. The serial interface ports were
female DB-9 connections (the same as on the original Macintosh 128,512
and Plus) as opposed to the standard IBM male DB-9 serial port connectors
which the entire PC industry adopted and is still in use to this day.
The Centronics printer port is a non-standard DB-15 female connector which
only Atari used. Almost all other computer systems adopted
the PC standard female DB-25 connector.
While the Atari 850
was the only interface Atari ever sold to the public, many other devices
and variations of the Atari 850 were made or used the Atari 850 interface
case to house other various products. Even Atari's own service
division used the Atari 850 cases to house its various (SALT) Stand
ALone
Test
units. Other outside companies and parties used the Atari
850 cases for many odd and unusual projects, click below to see these various
850's.