One of the most common microprocessor architectures today is the ARM RISC architecture from ARM Holdings. ARM Holdings grew from Acorn Computers, and Acorn Computers has its roots within the famous Sinclair empire.

Sinclair Radionics, run by the inimitable Sir Clive Sinclair, designed and sold electronics devices such as radios, pocket calculators, digital watches and the world’s first pocket television. After striking financial difficulty in the mid 1970s Sinclair sold a 43% shareholding in Sinclair Radionics to the UK government run National Enterprise Board.

Facing a loss of control in his own company, Sinclair encouraged one of his most trusted employees, Chris Curry, to leave Sinclair Radionics and set up a new company, Science of Cambridge, intended to eventually become a wholly Sinclair owned company. At Science of Cambridge, Curry was approached by National Semiconductor with a design for a kitset computer to showcase National Semiconductor technology. This computer was sold as the MK14 and sold well.

Curry saw huge potential in the home computing market and tried to convince Sinclair to let him develop another computer product. Sinclair did not see a future in home computers and was not interested, so Curry left Science of Cambridge to pursue his vision elsewhere.
Cambridge Processor Units Ltd. was founded in Cambridge in 1978 by Chris Curry and Hermann Hauser, a friend of Curry’s who shared the same vision. They did some design consultancy work and in 1979 the renamed the company Acorn Computer, and released a 6502 based single board computer, the Acorn System 1. The System 1 was aimed at laboratory use and over the next several years multiple revisions incorporated much additional functionality.

In 1980 Acorn Computers released the Atom – a small home computer packaged in a solid plastic case and incorporating a full size keyboard. It was very functional and attractively priced. An updated version of the Atom was successfully pitched to the BBC as a computer for a BBC lead education programme, becoming the BBC Model A/B computer for which Acorn is probably most famous.

CPU: 6502 @ 1Mhz
RAM: 2KB expandable to 12KB
Video: Motorola 6847 Video Display Generator, 16x12 or 32x24 text, 256x192 up to 4 colours
Sound: 1 channel beeper

Interview with Chris Curry from October 1982 Practical Computing.
Your Computer also interviewed Chris Curry.
Micro Men is a BBC dramatisation of the relationship between Sir Clive and Chris Curry, and the impact they had on computing in Great Britain.

Spectravideo was founded in 1981 as a manufacturer of gaming accessories for the common systems of the day. They made a reputation as a joystick maker, under the Quickshot brand, and it is for this that they became famous. Their first entry into the home computer market was with the CompuMate keyboard expansion for the Atari 2600. This was a simple membrane keyboard and cartridge for the Atari games console which let you write and run simple BASIC programs.

In 1983 they produced their first real computers; the SV-318 and the SV-328. The 318 had a rubber keyboard and a circular direction pad on the right-hand side into which a small red plastic joystick could be screwed. I remember seeing the SV-318 in a computer store and being utterly entranced by the tiny red joystick. Its larger brother, the 328, was much more business like and serious, having more RAM and a real full-stroke keyboard. The 328 was advertised as having 80K RAM, although only 64K was available to software. Both were powered by a Z80A processor and ram Microsoft Extended BASIC. These machines are considered to be the precedent upon which the MSX standard was later based, but were not MSX compatible themselves. It was later, with the SV-728, that Spectravideo produced its first MSX compatible machine.

Many accessories were made for the SV-300 computers. One of the most notable was the SV-605 Super Expander - a huge box which plugged into the back of the SV giving it floppy drives and expansion slots into which a number of cartridges could be installed such as an 80 column video card, RS-232 serial port or additional memory. With the floppy drives the SV could run CP/M, an operating system with a large number of business applications. One of the more unusual expanders was the SV-603 Coleco Game Adapter which allowed it to play ColecoVision game cartridges.

Spectravideo ceased trading in 1988.

CPU: Zilog Z80A at 3.6Mhz
Memory: 16K Video + 16K program (SV-318) or 64K (SV-328)
Graphics: 256x192, 16 colours
Sound: AY-3-8910 3 channel

http://www.samdal.com/spectravideo.htm
http://www.spectravideo.org/manuals.html