Two men arrived at the door clutching a copy of that March edition of Practical Computing. They worked for a company looking to store digitised maps of the Mediterranean on personal computers. A software package, which they wanted Digithurst to design, would communicate with a Loran C navigation system. The target market was wealthy private yacht owners. We guessed this needed a device with a resolution far in excess of the MicroEye’s 256 x 312 pixels, but the prospective customers made it clear their boss wouldn’t take no for an answer. They just wanted us to tell them how much it would cost to make the system work. We plucked a figure of £12,000 out of the air. This was a ‘go away and leave us alone’ quote. A week later, I was on a Swissair flight to Zurich and, a week after that, a large box arrived at my house containing the target PC. At this point, the project stopped being sublime and became ridiculous …
The Compucolor was marketed as the world’s first colour microcomputer. It was an 8080-based PC with some good points, but one major flaw: its capacity to spectacularly self-destruct. Most computers with a built-in CRT have a memory location which sets the video line length. A zero at this address will cause the driving transistors and, ultimately, the PC’s power supply severe problems. The Commodore PET could be permanently disabled with a single address ‘poke’. However, this poke had to be explicit. A fault in the Compucolor’s BIOS caused data loaded from disk to overflow first into the graphics memory and then the registers of the CRT controller, with potentially disastrous consequences …
(An extract from The Ghost in the Labyrinth by Peter Kruger)
