Re: Sinclair Executive Calculator

From: Nigel Tout
Email: nigeltout@madasafish.com


The MP675 cells are Mercury type and are no longer available. I believe that they are nominally 1.35v, so four would give 5.4v. Same physical size cells that are available are the SG13 Silver Oxide cell which gives nominally 1.2v, and the AG13 Alkaline cell which gives nominally 1.5v. What I have done is to use two SG13 with two AG13 to give a total of 5.4v - the same as four MP675. This has worked with Sinclair Executive models and also early 1980s hand-held computers which take the four MP675. I always alternate between the two types (SG13-AG13-SG13-AG13) in case there is any tapping taken from the middle. This is the method I use, and, of course, I take no responsibility if anything goes wrong.