That's not an opcode. You can either do ld a,$aa out ($0f),a or ld c,$0f out (c),$aa Both of which are 4 bytes. In a message dated 4/2/2001 3:21:23 PM Eastern Daylight Time, dArkSk8eR@buffbody.com writes: > > ---- Jonah Cohen <ComAsYuAre@aol.com> http://jonah.ticalc.org