AndyF wrote:Was there anything to disrupt (in theory) the 'old skool' method ie a straight tape-to-tape ?
For instance, some early (ZX) speedlocks had pulsating leader tones (with clicks) which could play havoc with some tape recorders auto gain control.
To which the answer was to use a pair of HiFi decks where the recording deck had manual level control. I cannot see any way a tape could be made that uncopiable using high quality analogue equipment because the cassesstes being distrubuted had almost certainly been through a high speed tape duplicator, i.e. the same things used for pre-recorded music cassettes. Certainly at the beginning of the BBC Micro era these were anlogue machines running at some multiple of the final speed with the source of reel to reel tape.