A Hilarious and Ingenious Disc Protection Scheme for the BBC Micro

[NoLand]

I found this a fascinating and entertaining read:
“The cleverest floppy disc protection ever? Western Security Ltd.” by Chris Evans

The cleverest floppy disc protection ever? Western Security Ltd.

(Further information withheld in order to avoid spoilers.)

Via HN, https://news.ycombinator.com/item?id=25421648

[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.

[abc123]

As a bonus there is an interesting discussion on “disk” vs “disc” (I did not know)