Date : Wed, 15 Aug 2007 10:52:52 +0100
From : julesrichardsonuk@... (Jules Richardson)
Subject: Depraz mice + Master 512
David Harper wrote:
> Jules Richardson wrote:
>
>>> Standard mouse pinouts are:
>>>
>>> pin function
>>> 1 5V
>>> 2 (CB1) X Ref
>>> 4 (CB2) Y Ref
>> Presumably those are still outputs from the mouse to the BBC?
>
> Yes. From the mouse the two X and two Y outputs are of the same kind - they
> are simple on/off signals from two light detectors (for each direction)
> interrupted by spokes on the wheels connected to the rollers.
Thanks... hopefully I can swap pins around at the User Port connector itself
then rather than needing to make up an entire new cable (I'm not sure if I've
got any of the right connectors in the junk box :-)
Curiously, I noticed that my ACW mouse is wired with the same pins used as
these Depraz mice (although whether they perform the same function, I don't
know) - making it a possibility they were originally used with an ACW (I know
the person I got the mice from did once have an ACW, plus a few spares).
Curious, but then I'm yet to see an ACW that looks identical in build to any
other ACW :-)
> There are 4 disks. (One is in the drive in the photo.) See:
> http://www.cowsarenotpurple.co.uk/bbccomputer/master512/system.html
Ta. Thinking about it, the non-originals which came with my M512 [1] were four
disks - it's just that somewhere along the line I've picked up these two
originals (boot + GEM desktop) and for some reason the other two were missing...
[1] I think that M512 was my first Acorn :-) (the other M512 I'll be selling
once I get a mouse working with it)
>> And hmm, I still need to find where my user guide's gone...
>
> Don't bother. It is hopeless. Look at the Chris Snee version, along with
> Robin Burton's Technical Guide. Electronic versions on:
> http://www.cowsarenotpurple.co.uk/bbccomputer/master512/bibliography.html
Aha - ta :) It seems like mine's wandered off into the sunset (possibly with
the 'proper' Acorn M512 mouse, which I still haven't found!)
J.