I had the same question or very similar. I wanted to know how initiate TX or RX for 80C52. Thanks for you help. I think you participated at forum HELP ME...... The point is I received a program from someone of you, I think was Mr. Kumar, echo character program. I checked my hardware and I found some troubles, at now I can see the sent characters, that's means minimun system is ok. Now I am fighting with my own program, I think will test by parts.
Thanks again.