Hi. I think there are defaults for both the W and the A bit. So, as long as the defaults match your needs, technically you should not need to specify them. But of course, the code gets clearer if they are spelled out... Jan-Erik. -----Ursprungligt meddelande----- Fr=E5n: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] F=F6r Anth= ony Nixon Skickat: den 27 september 2017 11:34 Till: Microcontroller discussion list - Public. =C4mne: [PIC] 18Fxxxx Instructions Hi all, It's been a long time since asking a question here :-) I've started to use a 18F47K40 chip for a project and I'm still using assembler for it. In the other PIC families you could omit the destination bit (F) from an instruction as the assembler sets it as default. I gather this is not the case for 18F series when you can have a destinatio= n and RAM access bit Eg. ADDWF MyReg,W,A Do all instructions have to be fully written in this way? I am porting a 16F application to 18F because I need the extra ROM space. I= f this is the case then I will have to rewrite and qualify every instruction. cheers Tony -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .