I tried one on one of my computers and it didn't work. Are you saying the PC somehow reverts to the I2C-like keyboard interface method when you connect a keyboard?

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

I have one of this usb to ps/2 adapters:

And it really transforms usb to the i2c like signals that ps/2 uses, and I have no problems connecting my usb keyboard to my SBC.

Have you checked the connectivity of this device? My understanding is that these are completely passive and trivial pass-through devices. The PC uses the PS/2 protocol, and the keyboard (which is capable of using either protocol) chooses to use the PS/2 protocol as well. The intelligence is in the keyboard, not the adapter (or the PC)
Cheers
Ed

I tested my adapter, and yes, the PS/2 hardware is in the keyboard itself, so what that means, I could just add an USB plug on my sbc and it would work as well...

A USB socket which carries the PS/2 protocol? Innovative!

At least you could make look your sbc more "up to date".

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

I think, that was supposed to be a joke. It would just look like USB, however the protocol would still be PS2.

At least the USB connector is better for hot plugging - ground & power first, then signal.

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6502 sources on GitHub: https://github.com/Klaus2m5

Well, if we limit the answer to when USB keyboards were introduced for PCs, the immediate difference was that suddenly you could plug in a keyboard _after_ the computer was powered on.. something that never worked with PS2 back then, there were countless times I had to reboot the computer (not only PCs, but also e.g. SGI computers) b/c the keyboard hadn't been plugged in. Obviously that's not a deficiency of PS2, it's just that the drivers didn't use to handle that back then. Now some of them do, and you can insert and remove and insert PS2 keyboards and they'll work. But USB had this requirement from the beginning, so keyboards could do this right from the start.

Other than that, I don't think there's much to gain by using USB keyboards.. I collect PS2 keyboards. I use them for my microcontroller boards. It's so easy to add PS2 to a Propeller, for example.

-Tor

This document provides an example algorithm for use in a keyboard micro-controller to determine if it is being connected via USB or PS/2. See page 11.

http://www.freescale.com/files/microcontrollers/doc/ref_manual/DRM014.pdf

So it looks like the adapters are just straight through.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Since I do wear out keyboards with all my typing, I've been through many of them, and I remember one particular one I had in the late 1990's that crashed regularly. (They keyboard's microcontroller itself apparently crashed and didn't seem to have a watchdog timer to get it going again.) At the time, I had two computers using the same monitor and keyboard, with a switch to switch these from one computer to the other, which might have been a cause of the crashing (although other keyboards handled it ok). Unplugging this keyboard from the back of the switch box and plugging it back in always got it going again, and I never turned off the computers.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

If you wear out keyboards, you should try one of these. They have the same design as the famous IBM model M.

Or just get one of those old 101 key keyboards with the big din connector, like I did.
They are kinda hard to ware out.
Or you could also get a das keyboard (http://www.daskeyboard.com/model-s-professional/) since I saw it in many reviews, it also includes a ps2 adapter.

Wanted to make folks aware of a similar solution I have available for sale:

http://store.go4retro.com/ps-2-keyboard-encoder/

It is slightly more expensive, though it offers some additional configuration, and you can hack it to your liking. I am modifying the code to allow larger uC options to do KB matrix scanning in addition to PS/2, and I could add SPI if desired.

Jim