Kempston Micro Electronics was an electronics company based in

Kempston Kempston is a town and civil parish in the Borough of Bedford, Bedfordshire, England, situated around south-west of Bedford town centre. It had a population of 19,330 in the 2011 census, and forms part of the wider Bedford built-up area. The ...

Bedfordshire Bedfordshire (; abbreviated ''Beds'') is a Ceremonial County, ceremonial county in the East of England. It is bordered by Northamptonshire to the north, Cambridgeshire to the north-east, Hertfordshire to the south and the south-east, and Buckin ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

specialising in computer

joystick A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Also known as the control column, it is the principal control devic ...

s and related

home computer Home computers were a class of microcomputers that entered the market in 1977 and became common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a s ...

peripherals during the 1980s. The Kempston Interface, a

peripheral A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...

which allowed a joystick using the ''de facto'' Atari joystick port standard to be connected to the

ZX Spectrum The ZX Spectrum () is an 8-bit computing, 8-bit home computer developed and marketed by Sinclair Research. One of the most influential computers ever made and one of the all-time bestselling British computers, over five million units were sold. ...

, was one of the most widely used add-ons to the machine.

Interface

Kempston joystick interface Kempston Interface plugged into a Spectrum Plus ZX Spectrum KempstonJoyInterface

The Kempston Interface is a

interface used on the

series of computers that allows controllers complying with the ''de facto'' Atari joystick port standard (using the

DE-9 connector The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smallest connectors used on computer systems. Description, ...

) to be used with the machine. The interface itself would be attached to the computer's rear expansion port with a single joystick port on the front or top of the system. Apart from implementing existing joystick interfacing modes they produced their own standard which delivered the joystick state on the Z80 bus at port 31 (read in BASIC using IN 31). This meant that the joystick did not produce key-presses like the other standards, such as ''Cursor'', and the method was soon borrowed by other interface manufacturers and became quite popular. It was one of the most widely supported standards on the machine, coming out as the clear winner against other standards such as Protek and AGF's cursor-based solution and the Fuller standard during the days of the 48K Spectrum. When

Amstrad Amstrad plc was a British consumer electronics company, founded in 1968 by Alan Sugar. During the 1980s, the company was known for its Home computer, home computers beginning with the Amstrad CPC and later also the ZX Spectrum range after the ...

released the ZX Spectrum +2, the computer featured a built-in joystick interface that was software-compatible with Sinclair's ZX Interface 2 standard. However, the bundled ''SJS-1'' joystick was electrically incompatible with the Atari standard. The Interface 2 standard simulated keypresses on the numerical keys ( to and to being left, right, down, up, fire for the 'left' and 'right' joysticks respectively) and hence were ideal for games with no official joystick support but in which the keys could be redefined. Inserting or removing the joystick interface when the computer was turned on was inadvisable as it would almost certainly damage the computer hardware.

Mouse

* x-axis at port 64479 * y-axis at port 65503 * two buttons at port 64223

Joysticks

The Formula 1 is based on the Quickshot 1 and released June 1985. The Score Board has a base similar in size to a 48K Spectrum, with two fire buttons. Released June 1985. The Competition Pro has a square base, two large red buttons (for left or right-handed use), and a black pommel stick. It uses the

Atari 2600 The Atari 2600 is a home video game console developed and produced by Atari, Inc. Released in September 1977 as the Atari Video Computer System (Atari VCS), it popularized microprocessor-based hardware and games stored on swappable ROM cartridg ...

standard

DE-9 The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smallest connectors used on computer systems. Description, ...

connector and was primarily designed to work with the

Kempston joystick interface; it also works with the compatible ports of other home computers such as the

Amstrad CPC The Amstrad CPC (short for "Colour Personal Computer") is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the ZX Spec ...

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit computing, 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in ...

VIC-20 The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit entry level home computer that was sold by Commodore International, Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commod ...

, and later

Amiga Amiga is a family of personal computers produced by Commodore International, Commodore from 1985 until the company's bankruptcy in 1994, with production by others afterward. The original model is one of a number of mid-1980s computers with 16-b ...

and

Atari ST Atari ST is a line of personal computers from Atari Corporation and the successor to the company's Atari 8-bit computers, 8-bit computers. The initial model, the Atari 520ST, had limited release in April–June 1985, and was widely available i ...

. An

Atari 5200 The Atari 5200 SuperSystem or simply Atari 5200 is a home video game console introduced in 1982 by Atari, Inc. as a higher-end complement for the popular Atari Video Computer System. The VCS was renamed to Atari 2600 at the time of the 5200' ...

model uses the existing CX52 controller for the keypad functionality.

References

{{Use dmy dates, date=October 2019 Defunct computer companies of the United Kingdom Defunct manufacturing companies of the United Kingdom Defunct computer hardware companies Home computer hardware companies Game controllers ZX Spectrum Electronics companies of the United Kingdom Kempston Companies based in Bedfordshire