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AT to XT Keyboard Converter

I would like to know if there is a way to build this project to make it work as a connector for a XT keyboard to an AT motherboard. My idea is to replace my IBM 5155's motherboard with a 286/386 board and fit an adaptor like this inside the 5155's case so it can translate the scan codes from the IBM 5155 keyboard.

PS: I'm sorry I posted this same question as a reply to the Wiki for this project before realizing it was a Wiki...
 
Hi all!

I've bought this converter, it works, but I found unpleasant problem with it.

After power on, the keys Insert/Home/End/Delete/Page Up/Page Down do not work (I got
strange letters on screen and cursor moved unexpectedly).

But if to turn on NumLock and then to turn off/turn on the converter power, then the
problematic keys will be work properly!! Well, I just pulled out and inserted my AT
keyboard connector, but very important that converter still being connected to
motherboard. Feeling like that necessary to reset my AT keyboard, not converter
(since converter "saved NumLock status" and must still get power from motherboard
during keyboard commutation...).

I tried out manipulations with JP1, but unfortunately without effect.

Why this problem could happen?

Any ideas/advices will be great appreciated!

 
Does anyone have a problem with "sticky keys" on this device?

When I CTRL-ALT-DEL to reboot, my XT-IDE card will usually behave as if the ALT-key is held in (booting from Serial port).

If I hit the ctrl/alt keys rapidly a few times immediately after booting, this doesn't happen.
 
I have seen this too. I ended up with the same workaround- just poke the ctrl/alt keys a few times while the machine is going through POST to clear out the condition.
We may have to ask the XTIDE BIOS folks if they can help. I say that not because it's their bug to fix, but because they have the easiest path to apply a patch if we can come up with one. Clearing out the ctrl/alt status flags in the BDA memory at the start of the BIOS load might be all that is required.
 
hargle said:
I have seen this too. I ended up with the same workaround- just poke the ctrl/alt keys a few times while the machine is going through POST to clear out the condition.
We may have to ask the XTIDE BIOS folks if they can help. I say that not because it's their bug to fix, but because they have the easiest path to apply a patch if we can come up with one. Clearing out the ctrl/alt status flags in the BDA memory at the start of the BIOS load might be all that is required.
Click to expand...

Good, then it's nothing I've done wrong. I put together a few to sell on Ebay, and they were all showing the same behaviour, so I was a bit concerned...
 
if only I had a way to erase (so I could re-program) my PICs I would gladly try that firmware out... My stupid programmer doesn't support erase. :(
Anyone want to do a parts exchange with me? I have 4 keyboard converters I'd like to upgrade.
 
hargle said:
if only I had a way to erase (so I could re-program) my PICs I would gladly try that firmware out... My stupid programmer doesn't support erase. :(
Anyone want to do a parts exchange with me? I have 4 keyboard converters I'd like to upgrade.
Click to expand...

Do you live in the U.S.?
 
I have recently rewritten the firmware for my AT2XT implementation. At some point soon I'd like to redesign the PCB in KiCAD and then host it on CircuitHub so people can buy on-demand. Or perhaps someone can set that up for the original AT2XT implementation?

Hey ChuckG: Looks like MSP430 actually was a decent choice after all (see repo) :). Though I never would've known that when I originally wrote it.
 
At the time I did it--the PIC12F629 was the cheapest 8 pin MCU that was capable of the job. It was made clear to me that anything that wasn't a through-hole implementation would be a nonstarter.

Are there 5V 8 pin DIP implementations of the MSP430?

Today, on the basis of cost and horses per buck, there are many other choices. But oddly, not as many DIP implementations other than some PIC and AVR models.

You could probably take a low end SMT MCU and translate USB keyboard to XT for not much more than the original. How about it? Why should anyone have to scrounge for a PS/2 interface keyboard?
 
Hello,

How about auto-detect HOST system (XT/AT)? If an AT system is detected, then broadcast the signals directly.
This would be convenient for those who have a converter built into the keyboard body.
 
mac512 said:
I would like to know if there is a way to build this project to make it work as a connector for a XT keyboard to an AT motherboard. My idea is to replace my IBM 5155's motherboard with a 286/386 board and fit an adaptor like this inside the 5155's case so it can translate the scan codes from the IBM 5155 keyboard.

PS: I'm sorry I posted this same question as a reply to the Wiki for this project before realizing it was a Wiki...
Click to expand...

You read my mind i have 5155 and i like to replace the motherboard for a 286 one and have the same keyboard issue.
 
Turns out I'm going to need one of these... Can someone point me to the schematic and/or eagle files if they are available? I think I already have the code.

Thanks,
Scott
 
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