I want to archive the data casettes (Basic Interpreter and Games) of the Sharp MZ-700 series (Z80-processor-computer from 1982). These casettes are audio compact casettes. I want to use audacity. What upper frequency bound should I use? (I think the default 44100 Hz is too high.) I would use FLAC format to store. Is it appropriate?
FLAC, as it is a lossless compression, is suitable for your purpose.
And you are possibly right, 44.1kHz seems to be too much, I think even 16kHz might do the job, but I think I'd do it with 22kHz sampling. (If I had to design a compact cassette based storage, I won't go higher than 10kHz signals for sure...) You'd have to check the documentation, if anything like that is available...
Maybe I'd verify it by digitizing one cassette, then recordinging the digitized content to another cassette, and trying to use the copied one.
Also, I don't know, if it used stereo or mono format, that might be worth checking too.
By the way, how did you get that kind of computer here in Hungary? Wasn't that prohibited at the time? (COCOM list, etc...)
EDIT I had a second thought. Is it not possible to get the data in digital format from the MZ-700 itself? I mean instead of storing the analog content, that would get interpreted to digital content by the computer, it could be possible to store the digital dta directly. Ok, one would need an encoder software to get that to a cassette in analog format again, but that way, the quality of the content would not degrade, as it does with analog signals. This would make it a lot easier, and a lot less redundant. Intead of files of several megabytes, you'd have files of a couple of tens of kilobytes...