In 1979, the British magazine

Wireless World ''Electronics World'' (''Wireless World'', founded in 1913, and in September 1984 renamed ''Electronics & Wireless World'') is a technical magazine in electronics and RF engineering aimed at professional design engineers. It is produced monthly in ...

published the technical details for a "Scientific Computer". Shortly afterward the British firm Powertran used this design for their implementation, which they called the PSI Comp 80. It was sold in the form of a kit of parts for a cased single-board home computer system. The system was based on a

Z80 The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples were ...

Microprocessor addressing a mixture of 8 KB of system

RAM Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * ...

and

EPROM An EPROM (rarely EROM), or erasable programmable read-only memory, is a type of programmable read-only memory (PROM) chip that retains its data when its power supply is switched off. Computer memory that can retrieve stored data after a power s ...

, plus 2 KB of Video RAM. It used a

National Semiconductor National Semiconductor was an American semiconductor manufacturer which specialized in analog devices and subsystems, formerly with headquarters in Santa Clara, California. The company produced power management integrated circuits, display dr ...

MM57109N as a mathematical co-processor to speed up calculations. The monochrome

Video Display Controller A video display controller or VDC (also called a display engine or display interface) is an integrated circuit which is the main component in a video-signal generator, a device responsible for the production of a TV video signal in a computing ...

could simultaneously display combinations of 32 lines of 64 characters, and 128 x 64 resolution graphics by either displaying a normal character or a "pseudo graphics" character, with pixel blocks in a 2x2 matrix. A technique similar to the one used in the

TRS-80 The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of '' ...

- It could later be expanded to a higher resolution, although never to colour. Ahead of its time, it incorporated a number crunching coprocessor and a novel language embedded in EPROM called Basic Using Reverse Polish - BURP. Add-ons were developed for the system, including memory expansions, floppy and hard disk interfaces, various software packages and a disk operating system, SCIDOS, which was CP/M-compatible but also included features - structured (pathed) disk folders, etc. - now very familiar to modern-day PC users. During the mid-1980s, the designer of this system, John Adams M.SC., published a new version of the Scientific Computer - the SC84 (Scientific Computer of 1984). It was based upon a backplane and plug-in cards and modules and featuring a Hitachi HD64180 processor, up to 512 kbytes of RAM and a high resolution colour graphics system.

References

PSI 2020

External links

a picture of the advertisement for the PSI Comp 80 in Wireless World

Links to Wireless World articles
Home computers {{comp-sci-stub