Den Wed, 9 Jan 2019 17:46:57 +0100 skrev silverdr@wfmh.org.pl: > > I don't have a problem with a mouse that uses a serial protocol, > > but RS232 had the problem with the power supply, they had to use > > the DTR and RTS lines as power supply for the mouse and you can't > > draw much from them. > > And it was only once they managed to build one low enough power > requirements that could run off those lines. The first one I recall > had an additional power socket in the serial plug. I've had one of those. It had it's separate wall wart, which was kind of stupid as it could had drawn power from the keyboard connector. Micro controllers did consume a lot of power back in the days. A keyboard could draw 300mA from +5V (spec of my Cherry G80-3000 "made in West Germany"). My memory might serve me really bad but IIRC that mouse did actually get slightly warmer than the surrounding air, probably partially due to it being on 24/7 (as I didn't bother making some adapter to hook up the wall wart to the switched power pass-through on the PC). Side track: IMHO a bad thing with the PS/2 mouse and keyboard connectors were that usage of one connector for both keyboard and mouse were never standardized, so the usage of the free pins for one extra unit could be connected in two different ways and it was mostly only laptops that supported this. I have a FujitsuICL PS/2 keyboard with a port for the mouse under the keyboard, but that would only work with FujitsuICL's own desktop PC's and probably a few laptops. -- (\_/) Copy the bunny to your mails to help (O.o) him achieve world domination. (> <) Come join the dark side. /_|_\ We have cookies.Received on 2019-01-10 21:02:17
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