Hey there, Ok, question here...what's a good way to toggle the nth bit of a byte when n is stored in a register? For example: ld a,3 ; ; Necessary code here ; And the 3rd bit is set/reset. I thought of creating a bitmask on-the-fly then XORing it, or perhaps making a lookup table...but I'm still not too sure. Help? :) Later, James. - James Matthews Generation5: http://www.generation5.org/