Teletype Tales Part 3

Last time I bought a mouse (which was only a couple of months ago), the ones in the local Maplin were labelled as 'USB' or 'PS/2' on the box. Als on RS232 seiral ones at all. Not hat it mattered for what I wanted. I didn't want a mouse at all. I wanted a dual phototransitor to fix a shaft encoder, and a cheap PC mouse was the easies way to get it. I would argue that quadrature mice are not serial but prallel in that the states of the 4 quadrature signasl and the <n> buttons are all available simultaneously on the interfce connector. Yes, you have to look for changes in signals to see if/how the mouse is moving, but I don;t think that makes it serial. Mind you, I am old enough to rememebr descriptions like 'bit parallel, characger serial' for the Centronics interface, meaning that while all the bits of a given character are presented in parallel, the characters of a line are sent one after another -- serially. I also remember digital measuring instruments with a fully parallel BCD interface, whiuch would have perhaps 32 data lines for the 4 bit BCD of each of the 8 digits. All valid at the same time/. -tony