The Nascom 1 was the most popular British made computer kit in the U.K. It was an affordable single board Z80 based computer with a keyboard attached by cable. It came as a kit or ready-built.
Why Nascom? Because the idea of a low cost computer intended for U.K. hobbysts was originated by an American company called Nasco. However, the board was designed in the U.K. by Shelton Instruments Ltd that, later, also designed and sold the Sig-Net
The minimum configuration featured 2 KB RAM and 1 KB ROM monitor, but the Nascom could be gradually extended into a system that was powerful enough to compete with many home computers of the time, Pet, Apple or Tandy.
Actually, the RAM area was divided into two parts: 1 KB for user program and data and 1 KB for storing characters displayed to the television. The ROM monitor provided basic functions: enter program and data, display memory content and processor registers, save and load programs from a tape recorder.
A whole range of peripherals and expansions were available from independant suppliers, as well as a vast range of software and many user groups. Several magazines dedicated to the Nascom and its relatives, the Gemini computers, were published. Many languages were available including BASIC, PASCAL, C, FORTH, etc.
I remember building one of these while at college learning to become a TV engineer. It got me interested in computers and led to me working for the same college (I''m still there after 24 years!). We had 8 of these which we used for microprocessor $ control systems courses. They were mounted in 2U rack cases and expanded to 16K. I was so impressed with them that I built one for myself. The one problem I had was with the siting of the keyboard cable which would produce spurious characters until re-routed away from the power supply. I still fondly remember programming in assembler on these machines.
Monday 26th November 2012
Paul Thomas (UK)
$$ Was I only only person to make use of the 8 bytes of "spare" ram at the end of each display line?
No, I remember that well. Often these days, when writing some code and allocating Mbs to a memory array without a thought I think back to those days when every byte counted.
Thursday 27th September 2012
Nick Burnard (UK) (UK)
Like Frank Burgum, I bought mine from Henry''s Radio, although a little later in december 1979. Mine too grew$ 64kb of ram, and a 20mA loop 110 baud teletype printer! It was a great system at the time, and only having memory from $0c80 to $fff and a stack that went down from $fff made things interesting to say the least! It made developing code an artform. Was I only only person to make use of the 8 bytes of "spare" ram at the end of each display line?