Nascom

Nascom 2 Computer, September 1981

The Nascom 1 and 2 were single-board computer kits issued in 1977 and 1979, respectively, based on the Zilog Z80 and including a keyboard and video interface, a serial port that could be used to store data on a tape cassette using the Kansas City standard, and two 8-bit parallel ports. At this time, including a full keyboard and video display interface was uncommon, as most microcomputer kits were then delivered with only a hexadecimal keypad and seven-segment display. To minimize cost, the buyer had to assemble a Nascom by hand-soldering about 3,000 joints on the single circuit board.

The original Nascom 1 was designed by Chris Shelton. Shelton’s design work was outlined in a series of articles published in 1977 and 1978 by Wireless World magazine.

Model	Nascom 1	Nascom 2
Introduced	December 1977	December 1979
MSRP (price)	£197.50	£225
CPU (µP)	Zilog Z80	Zilog Z80A
CPU speed	2 MHz	2 or 4 MHz (switch on main board)
Monitor/OS*	NAS-BUG 1 (1 KB EPROM)	NAS-SYS 1, most were shipped with NAS-SYS 2 (2 KB ROM)
RAM	2 KB (1 KB used for display), exp. to 64 KB	8 KB, exp. to 1 MB
Discontinued	1979	1983
* A debug monitor and simple operating system (OS) was included with the devices. CP/M versions 1.4, 2.2 and 3.0 were also available later. The display of the Nascom 2 consisted of 48 columns by 16 rows, white characters on black background with no graphics. It was possible to buy an add-on graphics chip (approximate price £20 in 1980) for the Nascom 2 that added another 128 graphics characters. The built-in Microsoft BASIC (8K ROM) interpreter could use these graphics to create a crude, blocky 96×48 graphics display.

The predecessor of Borland's very successful Turbo Pascal compiler and integrated development environment (IDE) for CP/M and DOS was developed by Anders Hejlsberg of Blue Label Software for the Nascom 2, under the name Blue Label Software Pascal, or BLS Pascal.

An interface bus, initially proprietary but quickly superseded by the 80-bus, allowed many other cards to be added to the Nascom, a progression which led to the Gemini 80-bus system which was, for a while, used as an industrial process controller. British Cellophane used several to continuously monitor thickness gauges attached to plastic sheet production lines. An 80-bus compatible network card enabled both Nascoms and Geminis to be used in office environments.

External links

• Dedicated user group
• Nascom homepage, with software and documentation
• Nascom Nostalgia
• Nascom / Gemini / 80 Bus, large archive of material
• Working Nascoms in the UK