On 04/02/12 20:15, Tony Duell wrote:
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...?"
ARGH! That's not pleasant...
I asume the next workpiece that drill was used on was your (ex?-) friend ;-)
No. But I did hurl a series of rather colourful adjectives at him...
Is this the clipped-togheter membranee keyboard that
Acorn used at one
point?
I think so. It has the feel of a mid-90s PC keyboard...
Connection is via two plastic ribbon cables with black (carbon?) tracks
and contact pads.
If o, I thin it comes apart from the bottom (unclip
the metal
backing plate, then take off the memberane layers). The LEds have their
leadouts bent over the keyboard moulding and come into contact with pads
on one of the membrane sheets.
I assume it can be reassembled without damage?
Most membrane keyboards I've looked at can be disassembled, but are
either difficult or impossible to reassemble.
It's worth making sure it;s not contact trouble
between the LED and the
seeht before you replace them.
That's a good point... I might attack the LEDs with some contact cleaner
first, then.
Indeed. Using
Mk.1 Eyeball, they're 0.1in pitch. A KK would probably
Watch out.. As you must know by now, there are 2.5mm pitch and 0.1" pitch
connecotrs, and it matters on something with 9 or 10 pins...
One of the many alternative uses for a roll of 'rainbow' IDC cable :)
Pass on that
one. What are your thoughts on the full-size DIN connector?
The connector isn;t too bad, athough I wish the isulator round the pins
was made of a plastic with a higher melting point. Often at least one pin
moves out of the right position when you solder them.
Ugh, too right on that point. I usually buy a socket and a plug, mate
the two connectors, put the whole thing in the Panavise then use a set
of 'helping hands' to hold the wires while I solder them. A little
over-the-top, but it keeps the pins nicely in line.
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
I think I'd have used a 240 degree one there. It's less likely to get
mis-connected to an audio device.
I think the "IIC-BUS" label is enough to stop me. Plus I don't have any
audio gear which uses those plugs, and the A3000 is the only machine
with that particular mod. The RISC PC used to have it (slightly better
done, using a spare Podule backplate, a DIN41612 plug and a Eurocard
protoboard) but I removed it when I put the second slice in and haven't
seen the board since.
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...
:-).
... And then I'll make it display Twitter feeds on Teletext! Fun for the
whole family.
Oh, and of course the Clock Cracker and other Ceefax test cards,
assuming I can find page-source for them. I think the Viewdata
Preservation site has those.
Indeed... There are some phone plubs with a sliding
sleeve on the outside
so tha the froudn makes first, but they are not common...
I was wondering if anyone had done that...
Nice idea, but expensive and I'll bet prone to failure (springs don't
last forever).
Probably rather pointless too -- most of the time, phono plugs go in
when the stereo is set up, and are left until a house-move or whatever.
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/