My *New* Acorn BBC Model B

I recently won an eBay charity auction for a BBC Model B “Micro”, which came bundled with a Microvitec CUB CRT monitor, an Opus 5802 5.25″ FDD, and some miscellaneous items like joysticks and boxed games.

What’s especially interesting about this machine is that it has been signed by Stephen Furber, the principal hardware engineer for the BBC Micro.

Charity auction bundle: Acorn Model B, Microvitec CUB CRT, and Opus 5802 FDD.

The auction was set up by a Manc chap called Darren Fletcher, who is auctioning parts of his collection to support Wood Street Mission, a charity which fights child poverty. His eBay profile is available here, for anyone who might be interested.

I’ve worked on several Acorn and BBC computers in the past, including Model Bs, but I’ve never actually owned one until now. So, this setup is definitely going to be remaining in my collection!

The Model B itself is in really nice shape, and has already been refurbished by RetroClinic, including repair of a faulty RAM IC and VIA IC, and replacement of all the electrolytic capacitors in the internal power supply – the Model B features mains filter capacitors, which dry out and crack with age and causing them to explode during use, so should always be replaced before using one of these computers.

The capacitors I replaced in one of my previous Model B PSU repairs, including the broken X and Y mains filter caps.

The Microvitec CUB CRT monitor is also in nice shape, but is completely original so will require a service, and is missing its front badge – no doubt, I’ll be correcting these in the next few months.

The Microvitec CUB monitor, commonly used in UK schools in the 1980s.

The Opus 5802 5.25″ FDD was sold as untested, and was in pretty nasty shape, covered in grime and permanent marker.

Despite its initial looks, the case has already cleaned up really nicely – because the case is painted, I couldn’t use IPA to remove the marker, but some Cillit Bang and a good scrub with a toothbrush has done the job really well.

I noticed that the end of the data cable was loose inside the case, so dismantled the drive to re-attach it internally, then installed some proper strain relief for both the data and power cables using some small cable ties.

Once I’ve got some spare time, I’ll service the drive (clean the heads, and lubricate the stepper rails) and give it a try with some suitable disks to see if it works.

The Opus 5802 5.25″FDD following its initial clean.

Published by themightymadman

My name is Adam Wilson - I'm an electronics engineer based in the North East of England, UK, and I like tinkering with old junk. In my spare time, I collect, repair, refurbish, and (sometimes) sell vintage computer systems and peripherals, typically from the 1980s (the likes of Commodore, Sinclair, Acorn, Apple, Amstrad, and Atari).

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