Is there any way to connect a cassette player to a computer, in order to transfer data from a cassette form to a pc file? Just a qustion I have ben askd by a colleague to which I have no clue.
How to Transfer Cassette Tape to Computer
How to transfer a tape to a CD using Audacity (Audacity is free audio editor software)
Interesting question. I did a bit of searching and found that the cassette data files seem to be proprietary depending on the platform. For example, I found a bunch of utilities to read and write from Commodore 64 data cassettes. Apparently, to use those you hook up a plain ol’ cassette player to the audio in of your PC. I’m not sure though and I didn’t play with any.
Did he tell you what system this is for?
On preview: I assumed he wanted the code off data tapes, not the audio. If he just wants music and whatnot, then x-ray vision gave the answer 
I think it may well be (self recorded) audio. I will forward on any links to him, he can choose amongst them. Thanks guys.
Ah yes, all those years ago my Commodore VIC-20, and later the 128, could use an ordinary tape recorder to save data. I can’t remember now, but I don’t think it was audio at all.
Of course, there was no FAT, so you had to keep track of the counter on the recorder as to where any file started and stopped, so as to get back if you wanted to reload it into memory. A bit primitive, but before they came out with an external floppy disk drive, that was all there was.
In fact, we called it a “stringy floppy.”