A history of the BBC Microcomputer   

The BBC Microcomputer was developed by Acorn Computers. It was built to be used by children in schools as part of the BBC Computer Literacy Project. The BBC Micro, as it was popularly known, was an expandable multi-purpose computer system.

The BBC Micro was the most popular of all the computers built by Acorn. It originally came from the design of an existing project called the Acorn Proton during 1980. Acorn decided to adopt its earlier 6502 processor as the CPU for the machine and provided an interface port to connect an auxiliary processor. It was also about this time when BBC started their Computer Literacy Project and they were searching for a computer system to use. Required specification was given to several computer makers including Acorn, Dragon and Sinclair. Acorn submitted the specification of the Proton and it came closest to the requirement of BBC, and so the BBC requested to test the machine.

Everything was going well for Acorn except for one thing - the machine was non-existent. A meeting was set on a Monday and it was agreed to conduct a test on a Friday. A team of Acorn engineers hurriedly set out to work and on a Wednesday evening they did the first test. But the machine did not work. The repair work went on until Friday morning. At around 7am the solution was realized – the problem lay with a timing discrepancy between the sample machine and the development kit. It was fixed and at 10am the meeting took place. The BBC team were satisfied with the results and gave the contract to Acorn to supply them with 12,000 computers. The Acorn Proton project was then renamed and called the BBC Microcomputer.

To make the BBC Micro perform at higher speed, the computer circuits needed were ordered from Ferranti. The first batch of chips delivered did not perform according to the specified speed range but Ferranti was able to modify them and delivered them back to Acorn in just 3 days.

There were two versions of the BBC Micro, the Models A and B. The two models featured a 6502 processor with a clock speed of 2 MHz, 32 Kb of ROM, and BBC BASIC I language. The machines were packaged with a standard RGB monitor, cassette, RS423 serial ports, User port, the Tube with 1 MHz bus, and special ports for expansion. The main purpose of the Tube is to link a second processor. The major distinction between the two models were the RAM capacity that they carry, Model A had 16 Kb while the other model had 32 Kb. Model B also had two extra ports in which a printer and a disk drive can be connected.

A modified version was also launched for the Canadian and US market. The modified version was a clone of Model B with the inclusion of speech synthesizer and BBC BASIC III language. However, it did not attain similar degree of success as in the UK due to FCC approval delays. The BBC Micro Model A was priced at £235 and the Model B was £335, and was afterwards raised to £299 and £399 respectively. This was a lot of money in the 1980's. Their combined sales reached 1.5 million units until the computer was discontinued in 1986.

The BBC 'B'. An excellent machine for the time. Can't remember it crashing too often. However, if your modern PC keeps crashin, we can help. We repair software errors and resinstall Windows onto computers in London.

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