You don't need a UART to send and receive serial data.
Software alone suffices.
Here's the code. Published in Embedded Systems Programming, December 1991 Return to articles list Return to TGG's home page Please subscribe to The Embedded Muse , a free biweekly e- newsletter with hints, ideas and rambles about firmware and hardware in embedded systems. No advertising, just down to earth embedded talk. I love cheap hardware. There's little more intellectually satisfying than replacing a lot of complicated, expensive components with a bit of cleverness.