On Tue, 9 Jan 2001 11:39:20 -0500 Lawrence Walker
<lgwalker(a)look.ca> wrote:
> I thought the keyboard was a standard IBM
XT-compatible?
Nope. I have about a 1/2 dozen of the IBM PC/XT
K-Bs. Those
hefty beasts are my favorite k-b. Also a couple of the XT/AT
switch type. This Amstrad does have a 5-pin DIN, but the pins are
arranged differently than on the PC.
Oh dear, how embarrassing, I was completely wrong. I had a
look at the plug on the PC1512 at home, and of course it's
a six-pin DIN plug. The outer pins in 270-degree layout
and an extra pin in the centre. I worked with one of those
That is, of course, a standard 6 pin DIN plug.
I know that Amstrad used that connector on the PC2086 (later XT clone
with VGA graphics on the motherboard) -- I have that machine and the
service manual. The 6 pins on the plug were the standard 4 lines of an
XT keyboard (+5V, ground, clock, data -- I have no idea if the data
protocol was the same as IBMs) and 2 pins that were for the mouse
buttons. The mouse plugged into the system unit, the button signals
(grounded by microswtiches in the mouse when the button was pressed)
were sent down the keyboard cable, detected by the microcontroller in
the keyboard and sent back to the system as key up/down messages.
The connection on the side for the mouse is a DE-9. Are you
saying it wouldn't function without a K-B. If so, is the mouse also
proprietary ? A 3 button mouse came with this 1640HD20 and I
just tossed it in my mouse box among the multitude of others
figuring it was standard. Was this likely not the original mouse ?
Since it won't start up w/o a K-B I haven't been able to check the
HD for configuration, altho the HD does seem to work.
My 2086 came without a mouse. I converted an clone
mouse for an Atari
ST (IIRC -- it was just a plain 2 button quadrature output mouse), and
thus got to find out what the signals were and where they went.
I have no idea if the PC1512 is like this, but it might be.
-tony
One of my ST mouses (mice ?) has a simple switch to change it
to an Amiga mouse. I also have a Kraft joystick with DE9 and
DB15 connectors and a switch to change between Apple IIe and
PC. There was a box from Practical Peripherals called Mouse-
Master to switch between STs and Amigas. Seems like it shouldn't
be too difficult to make an all-purpose connection box for different
platforms. I also have a 4+4-input 1+1 output ABCD box, to use a
single mouse and K-B with multiple systems, that are readily
available, which would simplify the project. Any "gotcha's" in this
scenario ?
ciao larry
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