Thanks all again for looking into my problem.

Bert :
the worst part of the problem is that everything works fine in the simulator..... When 'going live' the problem occurs.....

Erik :

Some time ago I made an transmit routine exactly according to your example which works flawless.
My RX buffer routine is working fine as well
The problem is how to manage both the transmit and receive buffer without 'getting in each other ways'.
I'm starting to think that what I want to do is not possible but on the other hand : there a lot of devices which use some sort of technique that I'm looking for. Like baudrate converters, midi to rs232 converters. A baudrate converter is basically what I'm trying to make. Only I don't change the baudrate....
and later (when the serial routines work) I'will do some processing on the received data and transmit the altered data.