Convert USB keyboard to PS/2 or AT?

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Re: Convert USB keyboard to PS/2 or AT?

Postby Samir » 2017-12-24 @ 08:00

cyclone3d wrote:Just an update. I received these the other day and they are brand new in original box.

I'll post another update when I test.
Please do. I'm interested in how these work since I have a few applications that could use it.

Small world too. I spend a lot of time in the Huntsville area, especially in the car enthusiast scene. :cool:
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2017-12-24 @ 18:55

+1
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2018-1-19 @ 23:56

Did any of you who bought that NTI converter actually get it to work with a modern quality mechanical USB-ONLY keyboard ?

If so, any chance you could state the exact maker and model number etc for those keyboards ?

Dual mode(USB/PS2) keyboards does not count, neither crap like the Logitech K120...

@Plasma: could you list all the boards you got working ?

And if any of you had to use some extra components/cables/adapters/whatever to get a particular board running, please elaborate.

Thanks.
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Re: Convert USB keyboard to PS/2 or AT?

Postby cyclone3d » 2018-1-20 @ 07:12

bestemor wrote:Did any of you who bought that NTI converter actually get it to work with a modern quality mechanical USB-ONLY keyboard ?

If so, any chance you could state the exact maker and model number etc for those keyboards ?

Dual mode(USB/PS2) keyboards does not count, neither crap like the Logitech K120...

@Plasma: could you list all the boards you got working ?

And if any of you had to use some extra components/cables/adapters/whatever to get a particular board running, please elaborate.

Thanks.


I'll try to test tomorrow. The only modern mechanical keyboard I have at home is a Corsair Strafe RGB. I'm guessing the PS/2 port won't provide enough power through the converter to power it though. Maybe have to use a powered USB hub. Not even sure that would work but I can try.

If that doesn't work, I'll test with my Cherry MX Board 6.0 which is at work once Monday rolls around.
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Re: Convert USB keyboard to PS/2 or AT?

Postby cyclone3d » 2018-1-20 @ 07:13

Samir wrote:
cyclone3d wrote:Just an update. I received these the other day and they are brand new in original box.

I'll post another update when I test.
Please do. I'm interested in how these work since I have a few applications that could use it.

Small world too. I spend a lot of time in the Huntsville area, especially in the car enthusiast scene. :cool:


Do you go to the car meets in Providence Main ? I drive through there twice a day :happy:
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2018-1-20 @ 17:51

Well, the PS2 port has a max output of 275mA, USB can suck up to 500mA per port. Not sure how much the converter itself eats up, and what is left for the keyboards...
NTI-support refuses to answer my email, so who the F knows.

Perhaps my lack of technical USB knowledge talking, but there might be some settings in the keyboards that are hindering this thing to work, maybe some standard signalling has been changed vs what the converter expects etc, or it only accepts power from the same cable as the data goes through, or.... ???
I am at a total loss here. And no keyboard effects are turned on at boot when it actually works, lighting or otherwise, when tested by connecting to a USB computer.

TRIED
- AC powered USB hub placed in between the converter and keyboard: NO keyboards work at all, not even the (USB only?) K120.

- plain USB splitter cable attched to keyboard cable, 1 split to the converter, the other to a simple AC travel adapter, in case the hub was too confusing: Now the K120 works, but still no life in the 'CM Storm Trigger Z' . I am guessing the K120 just sees this as a mere cable extension, and takes no power from the second split at all...(?)

- same splitter cable as before, but now connecting BOTH male ends to the converter, AND both PS2 plugs into the computers 2 ports (mouse/keyb): Same as above.

For the record, the K120 actually works directly with the converter, just using it as my only 'low power'(?) USB keyboard for comparison and control testing. As do some other keyboards, but they are all dual mode.

So, given that the sole purpose of this thing, for me that is, is to get to use modern quality USB-only keyboards on PS2-only computers, I'd say it is a total waste of money.

OR, maybe I've just been 'unlucky' with my choice of models ?
(tried 2 very different mech CoolerMaster keyboards, none worked)

If either that Corsair or Cherry board springs to life somehow, please let me know... :exclamation:
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Re: Convert USB keyboard to PS/2 or AT?

Postby Plasma » 2018-1-20 @ 18:38

I don't see what the problem is. Most USB keyboards are less than 100mA. I tried it with a Keyrah, an Amazon USB keyboard, and some other USB keyboard I had laying around. Worked fine with all of them. Pretty sure none are dual-mode.

Is there a keyboard you tried that didn't work? I'm not sure what you're all worked up about.
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2018-1-20 @ 18:46

CM Storm Trigger Z
CM Masterkeys Pro L
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Re: Convert USB keyboard to PS/2 or AT?

Postby Plasma » 2018-1-20 @ 18:58

Well I don't have any riced out keyboards. Can you disable the backlight? That's what's sucking all the power.
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2018-1-20 @ 19:04

As mentioned earlier, no backlighting is turned on whatsoever.
Only light showing is the num-lock. When it works, that is.

Unless these boards 'secretly' asks for the full needed power(incl for lighting), just in case/to have it on 'standby' even if not actually used - and then flatly refuses to work at all if not given to them.
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Re: Convert USB keyboard to PS/2 or AT?

Postby Plasma » 2018-1-20 @ 21:46

Could be. It may also not appear as a standard USB keyboard (does it have a special driver?)

You could try putting an externally-powered USB KVM in the middle.
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Re: Convert USB keyboard to PS/2 or AT?

Postby cyclone3d » 2018-1-21 @ 06:10

Ok, so I tested my Corsair keyboard and it didn't work.

I then hooked it up via USB on my Win98SE machine I was testing it on and it installed multiple HID devices. I am wondering if it has a controller between the keyboard controller and the USB interface since it can do all kinds of cool programmed lighting effects.

Since the Cherry MX Board 6.0 is just a basic mechanical keyboard with just backit keys and nothing else really, I think it has a better chance of working.
I'll test it on Monday and post back here with my results.
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2018-1-21 @ 18:45

cyclone3d wrote: I am wondering if it has a controller between the keyboard controller and the USB interface..

Sounds like something that could break the converters design, yes.

Plasma wrote:Could be. It may also not appear as a standard USB keyboard (does it have a special driver?)
You could try putting an externally-powered USB KVM in the middle.

I have only tested on boot so far, no Windows involved.
There is some special software to program the macro keys, but no other drivers needed - works fine at boot with no software at all (on a USB computer).

Have no USB KVM available. But don't think that would have helped. Already tried a powered USB HUB as well.
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Re: Convert USB keyboard to PS/2 or AT?

Postby Plasma » 2018-1-21 @ 19:23

The converter actually works with my KVM switch (keyboard only though, mouse doesn't work). But that's not a cheap experiment if you don't already have one.
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Re: Convert USB keyboard to PS/2 or AT?

Postby cyclone3d » 2018-1-23 @ 05:52

So it doesn't work the Cherry MX Board 6.0 either.

Not sure if it is a power thing or not as the lights on my Corsair Strafe RGB light up when plugged into the converter, but it doesn't detect it.

The Cherry MX Board 6.0 doesn't do anything at all and it is rated at 500ma, while the Corsair board is rated at 900ma max.

Edit: I went ahead and ordered a couple of USB power y splitter cables so I can test with a USB charger to see if it is a power problem or a compatibility problem.

Now I just have to wait for them to get here from China... Cue the 2-4 week wait.
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Re: Convert USB keyboard to PS/2 or AT?

Postby bestemor » 2018-1-23 @ 08:39

cyclone3d wrote:Edit: I went ahead and ordered a couple of USB power y splitter cables so I can test with a USB charger to see if it is a power problem or a compatibility problem. Now I just have to wait for them to get here from China... Cue the 2-4 week wait.

Good luck with that! :)

For me, the cables did nothing at all, as mentioned earlier. Seems like these keyboards are not receptive to such extra power. That is, not able to see that extra power is there, or not constructed for reception in this manner. Or something...(?)

Ordered mine from (within) Europe, a few $ more, but probably saved me 6 weeks waiting time, so... :P
(ordered Monday-arrived Friday same week, even with customs opening the envelope!)
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Re: Convert USB keyboard to PS/2 or AT?

Postby LSS10999 » 2018-1-23 @ 09:03

Modern keyboards are more likely to break PS/2 compatibility nowadays, and it's becoming really hard to find a keyboard that's both PS/2 and NKRO capable.

I'm currently using an active KVM which supports mixed PS/2 and USB input, and supports outputting in either. It enabled use of my Logitech wireless keyboard/mouse over PS/2 without issues, but unfortunately I could not get a USB mechanical keyboard of mine working on it (it supports RGB backlight and NKRO via USB). So it can only be a partial yet very expensive solution.

As for drivers, some modern day keyboards expose themselves as some unique USB HID devices (like XXX Gaming Keyboard), while still configured using default Windows HID driver. I'm not sure if the HID interface can actually extend the features of keyboard and mouse interfaces, but the special features, such as adjustable backlight, NKRO via USB, macro keys, work out-of-box once Windows finished configuring it.
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Re: Convert USB keyboard to PS/2 or AT?

Postby cyclone3d » 2018-1-29 @ 20:21

Here is a video that sort of helps explain how most newer USB keyboards do NKRO... with multiple HID devices.
https://youtu.be/AWkvzycD5PE

Multiple HID devices for a single keyboard is just not going to work properly with most/maybe no USB->PS/2 converters. you would almost have to have a system that takes it in as USB, then relays it via a PS/2 output. Like maybe a Pi or Arduino based machine.... would they even be able to use those devices that present themselves as multiple HID devices?

I've got a Cherry MX Board 3.0 on the way that supposedly will work with a regular USB->PS/2 adapter. Picked it up for super cheap, probably because it has the blank keycaps.

Also have a few other Cherry MX PS/2 keyboards that are being delivered today.. one beige and one black.. same model. Got them for cheap as well.

Anyway, I think I may make a list of tested working with this USB->PS/2 adapter and also a list of keyboards that work with standard USB->PS/2 adapters.

Maybe the same for mice as well.
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Re: Convert USB keyboard to PS/2 or AT?

Postby LSS10999 » 2018-2-03 @ 02:56

cyclone3d wrote:Here is a video that sort of helps explain how most newer USB keyboards do NKRO... with multiple HID devices.
https://youtu.be/AWkvzycD5PE

Multiple HID devices for a single keyboard is just not going to work properly with most/maybe no USB->PS/2 converters. you would almost have to have a system that takes it in as USB, then relays it via a PS/2 output. Like maybe a Pi or Arduino based machine.... would they even be able to use those devices that present themselves as multiple HID devices?

I've got a Cherry MX Board 3.0 on the way that supposedly will work with a regular USB->PS/2 adapter. Picked it up for super cheap, probably because it has the blank keycaps.

Also have a few other Cherry MX PS/2 keyboards that are being delivered today.. one beige and one black.. same model. Got them for cheap as well.

Anyway, I think I may make a list of tested working with this USB->PS/2 adapter and also a list of keyboards that work with standard USB->PS/2 adapters.

Maybe the same for mice as well.


As for multiple HID... I think it may not be entirely the case. There are some good mechanical keyboards supporting 12KRO on USB while including USB->PS/2 adapters (as well as full NKRO over PS/2). Those keyboards expose themselves as two HID keyboards. It seems some specific circuitry is needed on the keyboard itself to be able to identify whether it's been connected via USB or PS/2, and expose themselves respectively to the system.

As for conversion... It might be a good idea to make a dedicated controller using a Pi or Arduino but you might need to take latency into account, or it won't be very helpful in places where timing is important. Whether or not the keyboard expose themselves as multiple HID might not be important, just that if they could be properly relayed on time.

For mice, it seems these are simpler to verify than keyboards. Even when connected via USB with legacy USB support enabled in BIOS, if it does not work properly under legacy environments (legacy BIOS, or boot managers with mouse support like XOSL), you'll find it exhibiting the same behavior when connected using a USB->PS/2 adapter.
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