Same difference really... mov edi, blah mov byte [edi+1], 17 // Modify the instruction to mov al, 17 // Later... blah: mov al, 7 There

Same difference really... mov edi, blah mov byte [edi+1], 17 // Modify the instruction to mov al, 17 // Later... blah: mov al, 7 There's pretty much a 1->1 mapping between assembly language and machine code, so making a distinction doesn't make too much sense IMHO