[mrlonglong]

Fabulous explanation of how they did copy protection in the old days. I remember the 8271 well. I'm not sure why they used such an old chip with the BBC B, as it was quite expensive. The WD1770 was better and cheaper.

[LeoPanthera]

1770 upgrades were extremely common for the BBC Micro. (They are, astonishingly, still made.) The B+ and the BBC Master came with a 1770 by default.

[mrlonglong]

I preferred the NEC µPD765 though. Higher density.