S5/8 was a

serial communications In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are ...

standard devised in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

in the 1980s as a simplified subset of

RS-232 In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such ...

intended to make interoperability easier. Although published by the

British Standards Institution The British Standards Institution (BSI) is the national standards body of the United Kingdom. BSI produces technical standards on a wide range of products and services and also supplies certification and standards-related services to busines ...

as standard DD 153:1990, it was not widely adopted, and the BSI standard was later withdrawn.

Description

S5/8 differed from RS-232 in using 0 and +5 V signalling levels, simplified handshaking, and a fixed data transfer rate of 9600 bits per second. An 8-pin DIN 45326 connector was specified as standard, although a physically compatible 180-degree 5-pin DIN connector could be used to carry a subset of the signals. Data transmission consisted of frames containing one start bit, 8 data bits and one stop bit, with no parity bit. Two classes of device were specified, D and S. D-devices could supply power (5 V up to 20 mA) at the connector, whereas S-devices could derive power from a connected D-device.

Pin assignment

Applications

The S5/8 standard was adopted by a few British microcomputers, such as the Thorn EMI Liberator and the CST Thor XVI, as well as some versions of MSX computers, such as Yamaha CX11 and YIS-503 and its derivatives, the Sakhr MSX series.

References

* * * Serial buses {{electronics-stub