Hi,
I'm also looking for this cable. I don't want to deal with PCIF, I just want to save programs to tape, possibly to an MP3 recorder.
But I do not have the CI-7 interface cable.
I've tried hocking my oscilloscope up to the pins on the TI 74. Using the ground pin and pin 6 I see what looks like a digital signal when I attempt to save a file.
Could I just connect this signal to audio-in on a tape player and save the file?
If I want to send a program to the calculator, which pin should I send it too?
Or is it more complex than that?