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darkcoder
09-08-2004, 06:43 AM
Hello

I am not expert in hardware repairs so I ask for help
and apologize for wrong terminology I may use.
I repaired a broken A2000 keyboard, but I am not sure
of one thing. Inpecting the broken keyboard, I discovered that the problem was in the cable, namely the 5V wire
was broken.
So I found an old PC keyboard with AT connector and took the cable from it. I put the cable in the Amiga keyboard and now it works well.
However there is one issue not clear to me. As far as I know, the 5-pin AT connector is the same on both the Amiga and the PC. One of the pins is "not connected".
The original cable of the Amiga keyboard, internally has six wires: 5 of them are connected to the 5 pins and the sixth is connected to the ring around the pins (don't konw how to call it, hope you understand). So also the "not connected" pin has a wire connecting it to the internal of the keyboard.
The PC cable I found, instead, has only 5 wires, and the missing one is the one connecting to the "not connected" PIN. So, using such cable on the Amiga I left the "not connected" pin, really unconnected.
The keyboard now works fine, and as far as I understand,
if the "not connected" pin does what its name says, it does not matter that the new cable has no wire attached to it. But since I am a newbe in hardware repairs, I would sleep better if someone who knows such things could confirm my guess (or tell me I am wrong)!

thanks in advance!! :-)

Doobrey
09-09-2004, 04:17 PM
That extra wire just sounds like it`s the shielding for the cable.
As you`ve found out, it`ll run fine without it.

artman
09-11-2004, 12:51 PM
One thing to mention to other folks out there who may not know any better, but even though the AT keyboard plug will plug into the Amiga, under "NO" circumstance try to use the PC keyboard itself. I tried that as a newbie and belive me it was not pretty. Took quite a while to figure out what had burned inside and to unsolder and install new keyboard caps. I was lucky, could have been much worse.

Castellen
09-11-2004, 01:18 PM
The 5th wire you're thinking of is probably a reset line, which some AT keyboards used to have.

That pin is not used on the Amiga.

Everything is sent via synchronous serial data.
The 4 wires are +5V, ground, data and clock.

Pinouts and some more information here:
http://amiga.serveftp.net/HardwareBook/connector/index.html
Look in the keyboard connector section.

darkcoder
09-13-2004, 08:38 AM
thanks for all replys!
So it seems that I don't have to worry for the unused wire.

I also want to point out what artman said: apart from the cable the PC keyboard is completely different from the Amiga one, so don't use it!

regards