Hi there, Sorry to keep coming up with questions. I must be overlooking something with my test file. This file does character mode for 2 sets of 4 digits. What I don't understand is when I run this via my CC2 the numbers don't start at 0. The documentation states that ZP is shadowed at $2040 - $20FF so to clear ZP I cleared $2000 - $20FF. Why is this area not clear? BTW, this is my first 7800 program. As bloated as it is I actually think I'm understanding now. Thanks for all your help. Take care, Dennis