On Nov 27, 0:02, Tony Duell wrote: I didn't realise they were so different inside. I knew the Ace didn't use the ULA but I thought the basic architecture was similar to the ZX80/ZX81 (apart from the screen memory, which I knew about). There was certainly a rumour at the time that that was the case, but I dare say that was as much due to the similar size and shape of case as anything else :-) Perhaps "inspired by" is better than "based on". I have the manuals for ZX80, ZX81, and the Jupiter ACE, and the service manual for the ZX81, but the only one of those machines I possess is the common-or-garden ZX81. Twice I've just missed getting a ZX80, and I've seen a few, but I've only seen seen one ACE. -- Pete Peter Turnbull Network Manager University of York