On 01/02/12 21:13, Tony Duell wrote:
of pairs of wires. Moving wires in the mdidle of an
already-soldered
mini-DIN is a lot worse than DMD rework :-)
Try repairing the upper right corner of an A3000 motherboard some time.
That's the bit with all the fine-pitch tracks running under the Podule
connector.
This damage was caused by me mentioning to a friend "I need to take the
motherboard out and drill a hole in the case for the I2C DIN socket..."
He took a B&D drill, loaded a 10mm bit and drilled the case. With the
motherboard still installed.
"Oh, I thought you'd already removed the motherboard...?"
I did it with a Metcal MFR-1110, the 0.4mm conical bit and some
wire-wrap wire. It wasn't fun, and it wasn't easy, but it's electrically
sound and the Podule socket actually works now... :)
If it wasn't for the round profile of the tracks and the silver plating
(instead of green solder mask) it'd look fairly original. Now I just
need to find some instructions for replacing the Caps / Num / Scroll,
Power and Disk LEDs on the keyboard assembly.
I did find a CPC-branded 'replacement' mouse
for the Archmedes in a
chraity shop many years a go, No, I am not sellign it :-)
That's exactly what CJE were selling for ?43. At least a 4:1 markup by
my hazy reckoning.
They've got used Acorn RiscPC/A5000 mice for about 30 notes though, but
that's still expensive (especially for used).
button swithces on the front), but also with an
Acorn mouse that had
had the 9 pin mini-DIN cut off and been rewired to a DE9 plug to fit the
MG1.
Meh. The MG1 is infinitely cooler than (almost) any Acorn. A working
Phoebe would be the only thing that could hope to come close (and as I
understand it, there's only one of those -- an escaped prototype).
I repired the original mouse (I had some suitable
switches in the
junk box, and the buttons just clop on) but of course I also kept the
Acorn one. But it's no use on an Acorn machine any more.
Especially now 9P Mini-DINs are basically unobtainium.
Actually, I
could probably route one through the back. There are some
pads on the board marked "ALTERNATE MOUSE" which appear to connect to
the mouse socket. I'd sooner hide a PIC micro and a PS/2 socket inside
though. Get rid of the external adapter entirely :)
Are those pads at a suitalbe spacing to fit some kind of plug to the PCB
(e.g. a Molex KK)? If so, fit it and make whatever plug-in adapter you
need...
Indeed. Using Mk.1 Eyeball, they're 0.1in pitch. A KK would probably
fit, though I'd be more tempted to use a Harwin machined-pin header
(smaller pins, more likely to fit through the tiny holes).
The board's been wave soldered though, so the holes are full of solder...
I agree. I hade mini-DINs, They are painful to wire,
and don't make good
contact even when new. Are they really a DIN standard, or are they named
miniDIN simply becuase they look like a smaller version of the well-known
audio conenctor?
Pass on that one. What are your thoughts on the full-size DIN connector?
I thought those were fairly decent, if a little big. My A3000 uses a
5pin 180-degree full-size DIN for the I2C connector. I have a Solidisk
Teletext adapter which plugs into that, though it's scarcely any use now
there's no Teletext to receive. Maybe one day I'll build a VBI
inserter/databridge to go with it...
Now the phono connector... don't get me started on that one. Whoever
decided that the signal pin should make contact before ground should
have been subjected to a very painful end... Jack plugs are worse
though. Short-circuit on hot-connect, crosstalk, pops 'n' snaps
a-plenty, shoddy strain relief grips...
Cheers,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/