MK14
Encyclopedia
The Microcomputer Kit 14, or MK14 was a computer kit
sold by Science of Cambridge
of the United Kingdom
, first introduced in 1977 for UK£39.95. The MK14 eventually sold over 50,000 units. It used a National Semiconductor
SC/MP CPU (INS8060), 256 byte
s of random access memory (RAM) which was directly expandable to 640 bytes on board and 2170 bytes total. It used an 8 or 9 red light-emitting diode
(LED) seven segment display, there was also optional VDU supporting 32×16 text or 64×64 graphics. Input and output was a 20 key keyboard
and reset switch, with an optional 128 bytes of RAM and 16 I/O lines available by adding an INS8154N RAM/IO chip. Cassette-based and PROM storage were optional extras, a sound card was not included but a design for one was provided.
The MK14 could address up to 64kB of memory space by adding a few chips (the NADS address strobe indicated when the most significant 4 bits of address were available to be captured by an external latch); many pioneering home-brew computer magazines such as Personal Computer World
, and Practical Electronics carried details of user modifications.
Kit
-Animals:* kit, a young ferret* a short form of kitten, a young cat* Kit fox, a relatively common North American fox* Kit, a group of domestic pigeons trained to perform together in competitions-Companies and organisations:...
sold by Science of Cambridge
Sinclair Research Ltd
Sinclair Research Ltd is a British consumer electronics company founded by Sir Clive Sinclair in Cambridge. Originally incorporated in 1973 as Ablesdeal Ltd., it remained dormant until 1976, and did not adopt the name Sinclair Research until 1981....
of the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, first introduced in 1977 for UK£39.95. The MK14 eventually sold over 50,000 units. It used a National Semiconductor
National Semiconductor
National Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
SC/MP CPU (INS8060), 256 byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
s of random access memory (RAM) which was directly expandable to 640 bytes on board and 2170 bytes total. It used an 8 or 9 red light-emitting diode
Light-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
(LED) seven segment display, there was also optional VDU supporting 32×16 text or 64×64 graphics. Input and output was a 20 key keyboard
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
and reset switch, with an optional 128 bytes of RAM and 16 I/O lines available by adding an INS8154N RAM/IO chip. Cassette-based and PROM storage were optional extras, a sound card was not included but a design for one was provided.
The MK14 could address up to 64kB of memory space by adding a few chips (the NADS address strobe indicated when the most significant 4 bits of address were available to be captured by an external latch); many pioneering home-brew computer magazines such as Personal Computer World
Personal Computer World
Personal Computer World was a long-running British Computer magazine.Although for at least the last decade it contained a high proportion of Windows PC content , the magazine's title was not intended as a specific reference to this...
, and Practical Electronics carried details of user modifications.
External links and references
- Planet Sinclair - MK14 articles
- Planet Sinclair - MK14 photo gallery
- The Sinclair / Science of Cambridge MK14 Web Site, includes emulator software
- Making a reproduction MK14 - includes original manuals/schematics
- MK14 on a PIC
- MK14 NIBL basic on a pic