AltairClone.com

I have obtained useful images of cassette data input as shown in these images on the web.
http://bajama.mine.nu/~barry/hardware/A ... index.html
If you see a closeout sale at Radio Shack, grab one of these desktop digital recorders.
Barry

wouldn't be easier to take the measure at the mini jack out?

You are correct but I had it open anyway. Why don't you post a block diagram of the IO with pin outs and test points?
Thanks

Thanks for the tip about the digital recorder! I'm using one now and it is more reliable than using analog tapes. Not bad for $4.95 at Radio Shack!