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PS/2 Keyboard for old PC with high KRO


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So, I'm reviving my oldie 2001 PC. It works, but usb keyboard do not give it a justice. And thus I decided to buy PS/2 cream keyboard.

And, as I usually played with cheapest keyboards with 2 KRO (meaning that with specific key binding combinations , diagonal movement and one action button were enough to lock the keyboard and produce PS Speaker "beep") I know what are the disadvantages of such setup and I simply decided to get something better this time. Unfortunately, finding info on which keyboard offers which KRO is near impossible, as producers did not provide this info with mild exception of modern gaming keyboards which are out of scope. The scraps of information I managed to find suggest to look for the following, but each comes with its own shortcomings...

- Fujitsu keyboards from 90s - can't find exact model to look for, many were japanese only with strange layouts, and, uh, vertical enter.

- Siemens keyboards - found only slight mention, can't find used or new on auction, needles to say, I don't know which model.

- Cherry G80 or G83 - closest match so far, however, can't find info on KRO on these ones. and they're mechanical, and as I've used membranes for my whole life, I'm not really sure if I'd like it.

- IBM Model M or Unicomp model M, which has a awesome reputation and is available new and shiny, but, uh, the price, and again, no real way to check if I like buckle-spring feel without paying a priori.

- Zalman zm-k600s also looks promising, but lack of retro-look is a blocker here :)

If anyone have any recommendations, suggestions, or maybe even ol' trusty typer hidden in the drawer, it'll be much appreciated :)

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To be clear, what you are looking for are likely NKRO (No Keyboard Roll Over) keyboards, although likely a 6KRO would be enough. The issue is that this was a feature that isn't documented and it seems the only reason why there is a list of known KRO keyboard capabilities is because people have been testing various models themselves.


Also according to a post on stackexchange, the IBM Model M is 2KRO as opposed to the IBM Model F which is NKRO.


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Keyboard experiences:

My best keyboard is some cheap stuff, labeled HP SK-2880. Silver and black. That brings one second on a record lap in Grand Prix 2, because the keys are going very softly down, allowing a staccato of hitting the "A" key.

A keyboard called Fujitsu-Siemens from around 2000 is here, no model information. Originally beige, now yellow. Windows 98 symbols and the euro sign on the "E" and plenty of function keys at the top-right, for example "DOS", "Game", "Suspend" and the button with the coffee cup. That's a standard keyboard however and does not handle more than two keys, if you hit the wrong combinations. Still a good keyboard for typing, and reliable so far.

I wouldn't be afraid of mechanical keyboards or getting another keyboard in general. Of course it takes some time to get used to it. The IBM Model M (also only 2 KRO) is a tough machine. All keyboards (that are used on top of a table) should be that heavy, that gives them stability. But I don't find it too difficult to get back from the mechanical switch keyboard to a rubber mat keyboard.

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As cool lists as they are, they are fairly incomplete, but the hint that many G80 variants support NKRO, while others do not, is important. Model F AT is no go due to kay layout and high price for a remastered model. cmon, over 300 bucks?

I sent requests to Unicomp and cherry to check out if they do know what their keyboards actually can do :)

also, some other cool data source I found:




Edited by Mcinwwl
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  • 2 weeks later...

bump! for a reason, as, for my surprise, Unicomp employee answered me:


No, we do not support NKRO on any of our keyboards, though the Matrix on our Mini M is expanded to allow up to 10 keys concurrently pressed.

A more technical explanation of our rollover situation follows below:

Given the way we connect our switch matrix, our statement about phantom keys and rollover is, unfortunately, complicated. Our keyboards meet and exceed the Microsoft and IBM standards for multi-key combinations. Our keyboards will support any one to four modifier key combination (Shift, Control, Alt and/or GUI keys) plus a fifth key as long as:

1) No Left+Right modifier keys (Left+Right Shift, Left+Right Control, etc.) are involved in the combination, and

2) Neither the Up Arrow, Pause key, nor the Caps Lock key are the fifth key.

Our original intent was to support multi-key sequences required by any Microsoft OS or Application and to the best of my knowledge, that's still true. Of course our keyboards will support other key combinations larger than five key sequences without generating a phantom key situation and there are some 3 key sequences which will generate a phantom condition. Consequently, it's difficult to make a generic statement beyond the one above.

As for rollover, the USB HID and boot protocol standards limit our USB keyboards to six key rollover. The buffer sizes and key processing in our PS/2 controller limit those keyboards to 7 or 8 key rollover.

Not what I'm looking for, though...

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