Category Archives: Acorn BBC Micro

Adding a PiTube co-processor to a BBC Master

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The BBC Micro and Master computers were designed by Acorn from the outset to support a second processor via the proprietary Tube interface. Typically Acorn’s external second processors are in enclosures that matches the aesthetics of the BBC Micro and contain a power supply, processor, RAM and ROM. Essentially a computer without a keyboard and video output. The only IO is via a custom ULA that provides four bi-directional FIFO buffers. The second processors connect …

BBC Master 128 Restoration

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I’ve been donated a couple of BBC Micros from a friend who is in the process of clearing out his late uncle’s house. The first, a BBC Model B, is in need of significant repair – I tested it after recapping the power supply and got the dreaded beep of death and no video. The second, a BBC Master 128, is in much better condition. Cosmetics The machine had been used in a special needs …

Recapping a BBC Model B Power Supply

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One of the issues that old equipment has is capacitor failure. And in mains-powered equipment, like power supplies, failure can be somewhat spectacular. I’ve started restoring a BBC Model B. It’s a bit of a barn-find, that was donated by a friend who is clearing out his late uncle’s house. The BBC Micro looks like it has been well used, but should be repairable. I made the schoolboy mistake of plugging in the power supply …