I've converted some cassettes to WAV files before, mostly as an intermediate step to MP3. I've simply connected a halfway decent player (in my case an old dual-deck component that went into a yard sale earlier this year) to the line input of a PC sound card and recorded. The process of recording one side of the tape and then breaking it into separate files for each track was a bit tedious, but I suspect that software exists now that will detect pauses in playback and save songs to separate files. Unfortunately, I haven't looked very hard for such software - all I've seen recently was a severely overpriced cassette deck that came with such software that was advertised as a way to archive cassettes to the computer.