The IBM 1009 Data Transmission Unit was an IBM communications controller introduced in 1960. The 1009 used the

Synchronous transmit-receive Synchronous transmit-receive (STR) was an early IBM character-oriented communications protocol which preceded Bisync. STR was point-to-point only, and employed a ''four-of-eight'' transmission code, communicating at up to 5100 characters per sec ...

(STR) protocol to transfer data at 150 characters per second (cps) 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." The 1009 attached to

IBM 1400 series The IBM 1400 series were second-generation (transistor) mid-range business decimal computers that IBM marketed in the early 1960s. The computers were offered to replace tabulating machines like the IBM 407. The 1400-series machines stored infor ...

computers such as the

1401 Year 1401 ( MCDI) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. Events January–December * January 6 – Rupert, King of Germany, is crowned King of the Romans at Cologne. * ...

In 1961 the transmission rate was doubled to 300 cps. In 1962 the 1009 was part of a test of data communications using the

Telstar Telstar is the name of various communications satellites. The first two Telstar satellites were experimental and nearly identical. Telstar 1 launched on top of a Thor-Delta rocket on July 10, 1962. It successfully relayed through space the fir ...

satellite to link two 1401 computer systems.

References

External links

Photo of a 1009 at the Computer History Museum

1009 Year 1009 ( MIX) was a common year starting on Saturday of the Julian calendar. Events By place Europe * February 14 or March 9 – The first known mention is made of the name of Lithuania, in connection with the murder of Bruno ...

IBM transistorized computers Computer-related introductions in 1960 Link protocols Communications satellites 1962 in spaceflight {{compu-hardware-stub