Hi Andy, Oleg,

thanks for formatting the code I didnt know how to do it but I will read the given information.

@ Oleg, wow you really read the code and your understanding is right. If you use clear display or other control commands it needs time. With zero waitstates I mean I have tested the routine by using teraterm and I used send file function with no transmit delay. All characters will be received perfectly, means no charcter loss. So this routine is running with zero waitstates including writing the chars. @ the display.

Saving the register inside ISR is not neccesary but as you can imagine I use this code also in other projects so its universal.

If you use polling method you will never reach zero waitstates so if you like the code you wellcome.

Bernd