Graphic 6502 Simulation

[Roy Mackel <roy@kdt.de>]

Once there was a program for the Apple II that displayed in highres-mode
the internal working of the 6502. You could run a program step by step,
and changes in flags, registers and program counter were updated
immediately. It was very nice for demonstrating how a microprocessor
works.

What was the name of that program?
Does anyone know where to get the diskfile?
(Probably at asimov, but without a name I've got no chance to find it.)

Thanks a lot for any advice
Roy