A Hilarious and Ingenious Disc Protection Scheme for the BBC Micro

[elb]

We’ve seen this series before:

On floppy disk protection

A nice new technical post from Chris ‘scarybeasts’ about the arms race of floppy disk copy protection schemes, mostly from an Acorn perspective: Many good links within. ‘scruss’ on Stardot adds: Weak Bits were a really big thing on the Apple II, going back to 1982 or before. It’s worth checking some of the 4am crack logs (like this one: The Kingdom of Facts) for the details. It seems that Datasoft did it with a modified C64 drive attached to an Apple II.

And another article on floppy disk formats that seems apropos here:

Low-level Explorations of Commodore's Soft-sectored Floppies

From Diaspora: https://www.pagetable.com/?p=1070 Images of Commodore floppy disk formats and data with some discussion of the sectoring and non-standard formats used for efficiency and copy protection.