Adding a PiTube co-processor to a BBC Master
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 …