Hi Nic, I have compiled your asm with put any problem unless I haven't "membank.inc" file, but I assume it has bank issues. It seems you didn't respect the directive column order. Also you forgot to declare that radix IS decimal for that kind of macro code.... (Famous Eric Smith uh?) Insert this line after the processor definition: radix dec I hope that's all abt. Regards, Dennis Crawley www.geocities.com/proyectosenpic From: "Nic Scheepers" Hi all, I got this code of the net so that I can explore using the hardware UART on the 16F877. I tried to compile this but the problem is I am getting on the following lines. aligned SET pow2&&((base&(size-1))==0) if (aligned&&!(base&(1<