Feeds

The BBC Micro turns 30

The 8-bit 1980s dream machine

Boost IT visibility and business value

High demand, low supply

With the BBC's imprimatur of quality, however, the Acorn machine proved a much bigger success than it might otherwise have been. On the back of positive comments from the computer press and the promotional opportunity provided by the TV series, it was decided by the BBC and Acorn to commit to the production of no fewer than 12,000 machines during The Computer Programme's January run and repeat broadcasts in April and June 1982.

Having launched the BBC Micro Model A and Model B in December 1981, Acorn quickly took all those 12,000 orders in the weeks before Christmas. The computers would then ship in January.

Acorn BBC Micro advert

Promoting the Beeb

At launch, the Model A was priced at £235 and equipped with 16KB of memory. It lacked many of the graphics modes and other features integrated into the 32KB Model B. The latter quickly became the most popular model of the two and a lust object for young geeks the length and breadth of Britain. However, increasing production costs very quickly pushed the prices up and, in January 1982, the A and B were priced at £299 and £399, respectively.

Many enthusiasts forced to use cheaper machines – Sinclair's £99 ZX81 and £125/£175, 16KB/48KB Spectrum; the £129 4KB Commodore VIC-20; and others – tried hard to persuade parents to stump up for the pricier machine. Others sold their current machines and took on paper rounds to finance the rest of the purchase price.

Inside the BBC Micro

Inside the BBC Micro
Source: Patrick Dubby

School playgrounds quickly polarised into BBC – or 'Beeb' – and Spectrum camps, with the odd folk with Dragon 32s, Oric 1s, Texas Instruments TI-949/4As, Commodore VIC-20s and, later, 64s, oscillating between the two groups.

Both BBC Models were based on MOS Technology's 6502A processor clocked at 2MHz. Their 16KB and 32KB of memory ran at 4MHz, allowing the graphics sub-system and the CPU equal time access to the memory, ensuring that the video chippery didn't hinder the processor's performance – as was the case with other home systems.

Underneath the BBC Micro

Round the back: (L-R) TV modulator out, co-ax video out, RGB out, RS423, cassette port, D-SUB analogue in, Econet networking
Source: Patrick Dubby

The Model A's reduced memory meant it was unable to drive all the system's possible graphics modes, labelled 0 to 7, the latter delivering the Telextext system courtesy of a dedicated chip on the motherboard, dropped from the A to keep the overall price down. It was the highest resolution modes – 0 through 3, including two-colour 640 x 256, four-color 320 x 256 and eight-colour 160 x 256 – that the A could not support.

Both units had UHF output to drive a TV, but the Model B also had a six-pin DIN connector for a monitor. Four-channel sound was generated by a Texas Instruments SN76489 chip. There was a separate port for cassette recorder storage, but Acorn offered an optional floppy disk controller for the higher-spec machine, and the really keen could equip a Model B with a hard drive controller and interface that tapped into the machine's "1MHz Bus".

Underneath the BBC Micro

On the base of the Beeb: (L-R) Tube, 1MHz Bus, User port, Centronics printer port, disk drive and power
Source: Patrick Dubby

Again, the Model B had RS-232 and Centronics parallel interfaces as standard, both absent from the A. Ditto the 20-pin "user port" for I/O projects, and the 40-pin Tube bus which allowed optional secondary CPUs to be hooked up.

A 16KB Rom chip held Acorn's Machine Operating System (MOS) and a second 16KB Rom stored the BBC Basic interpreter.

The essential guide to IT transformation

More from The Register

next story
Apple takes blade to 13-inch MacBook Pro with Retina display
Shaves price, not screen on mid-2014 model
iPhone 6 flip tip slips in Aussie's clip: Apple's 'reversible USB' leaks
New plug not compatible with official Type-C, according to fresh rumors
Top Gun display for your CAR: Heads-up fighter pilot tech
Sadly Navdy kit doesn't include Sidewinder missile to blast traffic
FEAST YOUR EYES: Samsung's Galaxy Alpha has an 'entirely new appearance'
Wow, it looks like nothing else on the market, for sure
YES YES YES! Apple patents mousy, pressure-sensing iVibrator
Fanbois prepare to experience the great Cupertin-O
Steve Jobs had BETTER BALLS than Atari, says Apple mouse designer
Xerox? Pff, not even in the same league as His Jobsiness
TV transport tech, part 1: From server to sofa at the touch of a button
You won't believe how much goes into today's telly tech
Apple analyst: fruity firm set to shift 75 million iPhones
We'll have some of whatever he's having please
Things are looking up in Flappy Bird sequel
'Swing Copters' offers the same gameplay but in a different direction
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.