23 Nov
2000
23 Nov
'00
9:19 a.m.
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..
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.
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?
-tony
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