On Wed, 25 Nov 1998 Sam Ismail wrote: Are you talking about digitised computer tapes or music? I have some digitised (VOC format) files of ZX Spectrum game tapes. For example, Altered Beast. Not sure at what rate this was sampled, but: uncompressed file size = 12,725,061 bytes compressed file size = 504,546 bytes Which is a pretty good compression ratio. That is using the lharc archiver; I imagine zip would give similar or better compression. There are lossless compression systems designed for audio, but I bet they weren't designed with computer tapes in mind. On Wed, 25 Nov 1998 Allison J Parent wrote: Many game tapes for e.g. ZX Spectrum, Commodore 64 used turbo loaders. Not sure what the highest data rate was, though at least some C64 programs loaded at 3000 baud. 3db point may not be completely relevant; at least for the old ZX Spectrum, you had to hook up the tape player with volume set at or near the maximum. For systems which (notionally) record a bilevel signal -- this may include almost all of them -- it may be that sampling at a very high rate and then doing some kind of post-processing of the sample to reduce it to 1-bit resolution would be beneficial; the result could be closer to the original signal output from the computer when the master tape was created. On Wed, 25 Nov 1998 Marvin wrote: Sure. Tape copy-protection was used by almost all commerical (game) software. This involved some devious tricks, as well as turbo-loading routines. It was designed to prevent people from copying games by reading into the computer and saving out again. It shouldn't have any bearing on sampling the tapes at all. Some techniques used were auto-run loaders, fast loaders and custom formats in general, greater-than-RAM-size blocks of data. -- Mark