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The Sinclair / Science of Cambridge MK14 Web Site
Last updated on 15th June 1998 by Paul Robson . Current DOS emulator version is 1.9
The MK14 specification :-
For me, it began with the magazine "Electronics Today International" which is still going. I was about 14 and had been subscribing for 3 or 4 years and was planning on being an Electronic Engineer. In the mid 1970's they ran a series about Microprocessors, largely based around the Motorola 6800. I got hooked...
Trouble was, in those days, there wasn't anything much to learn on. Many early trainer kits got you to enter machine code, sometimes via a hexadecimal keypad, sometimes via a bank of toggle switches. Usually, these machines didn't have much backing store, maybe cassette tape if you were lucky. You wrote your programs on paper first, hand assembled them, and typed them in.
Anyhow, not long after this, I got my first computer. It was called the SC/MP Introkit. It was an SC/MP board which was designed to be connected to a serial terminal, and a set of components to make a calculator display and keyboard into a program entry device. The replacement I/O part was all wirewrapped. I didn't know anyone else who had one then, (though I found one on the internet the other day) in fact, I didn't know anyone else who had a "computer". It taught me an awful lot ... like how to write compact programs. I suspect my dislike of 2 Mb Windows monoliths is down to this machine... and the Texas Instruments TI-57 calculator (50 program steps) which was the other half of my Computer education (I could touch type on the calculator keyboard....)
A couple of years later Clive Sinclair got into a squabble with the National Enterprise Board over his flat screen television , and lost the use of name "Sinclair Research". He set up "Science of Cambridge" which was later to become Sinclair Computers, marketing the ZX80, ZX81, Spectrum and QL. The first machine of this line was the "MK14" (shown above, left, probably, you know what browsers are like) which was basically the SC/MP Introkit with a proper circuit board and a cheaper keyboard and display (the Introkit used calculator parts) with some provision for extra memory and I/O. This was designed by National Semiconductor, who produced the kits.
It had an extra 128 bytes of RAM and a pair of I/O ports added, and provision for another 256 bytes of RAM (a total of 640 bytes...). It had a really duff keyboard, the first in a long Sinclair line of duff keyboards, and a duff initial ROM (sound familiar ?) and Sinclair thought they'd sell a couple of thousand.
They sold ten times that. According to Planet Sinclair they sold 25 times that... 50,000 of these kits.
And that convinced Clive Sinclair to go ahead with the ZX80 design which led to the ZX81 and Spectrum. All you guys out there who love your Speccy's - this is the wierd contraption you have to thank for it.
On other pages on this site....
None of this would have been possible without the assistance of Grant Searle, who photocopied all his MK14 and SC/MP documentation and sent it to me, and Ian Bradbury who provided a lot (a lot !) of extra documentation and programs. The MK14 shown is courtesy of Ray Aucote, whose machine it was.