The IBM 1009 Data Transmission Unit was an IBM communications controller introduced in 1960.[1] The 1009 used the Synchronous transmit-receive (STR) protocol to transfer data at 150 characters per second (cps)[2]: p.577 over a single point-to-point dial or leased telephone line. The system was advertised as being able to "link the magnetic core memories of IBM 1401 computers over telephone lines."[1][3]
The 1009 attached to IBM 1400 series computers such as the 1401[4]
In 1961 the transmission rate was doubled to 300 cps.[2]
In 1962 the 1009 was part of a test of data communications using the Telstar satellite to link two 1401 computer systems.[5]
{{cite journal}}
: Cite journal requires |journal=
(help)