On Jul 14, 12:45, Hans Franke wrote: The B-plus was a model introduced after the B but before the Master Series. It had a lot of features of the Master 128, but was in a case just like a Model B. The circuit board is completely different, though. Different processor (65C12, IIRC), 64K RAM expandable to 128K, shadow memory and extra modes, etc, and a very different layout. -- Pete Peter Turnbull Dept. of Computer Science University of York