When using the tasm80.tab file, I came upon the opcodes LD A,R and LD R,A They have a '1' at the end of the line (the class), so I guess they're four our processor. But I'm curious as to that this R means. It can't be meaning 'other registers' since they're all taken care for elsewhere in the table file. My guess is that it's a special system register like 'I'... --(Peter-Martijn)