Hi Franc ,Steve
Thanks for your help. You will not belive it but a couple of years ago i dit with lots of problems at firts and at the end it was working, I lost all the documents and stuff. Steve please look at the iodriver.asm of sys51 in there they sugest that you use rs and p2.1, r|wr on p2.0 but it still does not work. I would like if you could send me some of your source code,thanks very mutch. My e-mail baopv@rs.uovs.ac.za

Regard

Peet.