I have a problem. I've gotten a project from my school. I need to do a data-logging device, with a 80C535, a pc and an analog device connecting to the phone.
My problem is that the code for the PC, and the 80C535 has to be two way, and I just can not figure out how to do it.
If anyone has code that works, please let me know, do not hessitate to send me the code, or a link to it.

Yours Jesper L. T.