What is it ?

From: Lawrence Walker <lgwalker_at_look.ca>
Date: Thu Nov 23 17:19:06 2000

> > >
> > I have a bunch of MS, Mac. Atari, Commodore, Logitec and other
> > clone mice. They all have either the DB-9,or PS/2 or Mac sub-mini
>
> Many mice, of course, include electronics (a single-chip
> microcontroller, normally) to translate the quadrature signals into
> either async serial data or PS/2 type commands. Serial mice may well
> have DE9 connectors
>
> As may raw quadrature output mice, where the 9 pins are exactly right
> for a 3 button mouse. A reasonable rule is that if the mouse cable
> ends in a DE9-S (socket), then it's serial, if the mouse cable ends in
> a DE9-P (plug) then it's a quadrature-output mouse.
>
> Of course if you open the mouse up (this is normally not too hard --
> there are screws on the underside, possibly under labels), then you
> can see whether there's a microcontroller to convert the signals or
> not.
>
> > with keying pin. I seem to remember seeing mice with large round
> > connectors which I assumed were the same size as K-B ones.
>
> I've never seen a mouse with a full-size DIN plug..
>
 Good stuff Tony. Mice are not something that you see much info
on. Someplace among my books I have a fairly thick one on
programming for mice but I've never seriously studied it.

> > This has a shell diameter of 1/2". Possibly I'm not acquainted with
> > the round bus mice. I'll have to try the card in a ISA box with CGA
> > and Mono monitors and hope the magic smoke doesn't escape. It's
>
> A useful hint here is that on MDA and CGA cards, pins 1 and 2 of the
> DE9 monitor connecotr are ground, while on the EGA card, pin 1 is
> ground and pin 2 an LSB for one of the colours. The IBM EGA card
> (which will drive MDA, CGA and EGA monitors) has a jumper link on the
> card to connect pin 2 either to ground or to the appropriate signal.
>
> So a simple continuity test between pin 2 and ground will tell you if
> the card is expecting an EGA monitor or one of the older standards.
>
 Hmm, in my AT I have one of the full-length doubled-board EGA
cards and another spare. Not sure if they're IBM (buried at the
moment). I just took it for granted they would only support EGA.
 
> If you can get the PC to recognise the card, then you can look at the
> sync outputs (pins 8 and 9 on the DE9) with a frequency counter and
> identify what sort of monitor it's expecting.
Alas, never could afford one with money that could be better-
allocated. In one of the H-P newsletters around 1982/3 they went
extensively into their newest model. I did thirst for one at the time
but ISTR they were priced at a multple thousand figure.
>
> > about the size of a Hercules card with a much smaller chip count.
> > Might be just the thing for my heavily modified IBM PC to replace
> > the outsized color and mono video cards.
>
> Any particular reason not to keep the original cards in use?

Well with only the 5 slots available and an Intel Onboard 386 card
and other modifications it gets a bit crowded. I also have 2 other
non-modified ones as well as a couple of XTs if I want to look at an
MDA or CGA monitor. Never cared too much for chunky CGA
graphics in any case. Keep the IBM monitors more for authenticity.

BTW an """ ORIGINAL"""RARE""" IBM PC is selling on e-pay right
now for $135.00 and has had 45 bidders. Sheesh. I paid $5 for one
a couple of weeks ago at a thrift (with non-standard 20M HD)
 Hype sells !

ciao larry
 
ciao larry

>
> -tony
>
>



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Received on Thu Nov 23 2000 - 17:19:06 GMT