Member Avatar for Paladine

Well I never would have imagined that this was that hard to find. But does anyone know how you would make a USB keyboard work on an old computer that only has ps/2 keyboard and mouse ports?

I got the mouse to work with a USB to PS/2 converter that came in the box, but I can't seem to make the keyboard work? Why is it that the same coverter for the mouse does not work for the keyboard?


Thanks for any help in advance!

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Short answer up front: USB and PS/2 use completely different electrical signals and protocols. A passive USB↔PS/2 adapter only remaps pins — it works only with keyboards/mice that were built to speak PS/2 as well as USB (so-called dual‑mode devices). That explains why the mouse worked through the adapter but the keyboard did not. This matches what and hinted at.

Practical options and why they differ:

  • Keep using PS/2 keyboards where a PS/2 “keyboard wedge” barcode scanner must attach — this is the cheapest, most reliable fix and is what was getting at.
  • If the goal is to standardize on USB keyboards, use an active converter (a small electronic interface) that translates the scanner’s PS/2 keyboard output into USB HID for the PC. Passive adapters will not do that. The active converter must support “keyboard wedge” operation and the correct keymap/scan‑code handling.
  • Adding USB host ports (internal USB card) gives native USB support for keyboards, but it does not magically convert a PS/2 wedge scanner — that still needs an active PS/2→USB interface or a USB scanner replacement.

Quick testing and rollout checklist:

  • Confirm whether a keyboard is “PS/2 compatible” in the vendor spec before assuming a passive adapter will work.
  • Test any converter or keyboard on a single machine first (include BIOS/boot tests if pre‑OS input is required). Some converters emulate PS/2 only at the OS level and won’t let a BIOS screen be controlled.
  • For bulk deployment, trial one workstation with the chosen converter and scanner together in the actual application to verify timing, keymap, and wedge behavior before replacing many units.

This ties together the prior replies: ’s USB‑card idea solves host availability, ’s compatibility note is correct, and the active converter approach is the usual way to keep USB keyboards while supporting legacy PS/2 wedge scanners.

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All 11 Replies

Member Avatar for DMR

Just a guess, but it could have something to do with the particular model of keyboard you have; it isn't as though USB keyboards in general don't work through a PS/2 converter.

Why not just buy a PS/2 keyboard? They're dirt-cheap.

Member Avatar for ShawnCplus

Well as I was always taught in my A+ certification class, a keyboard is known as an FRU (field replaceable unit) which is a fancy name for, its cheap buy a new one/old one. Unless you want a fancy-pants infared keyboard you can buy one for under 20 bucks so just run down to your local walmart/radioshack and pick yourself up an old ps/2 keyboard they'll probably be hidden but look for them. Hope it helps
ShawnCplus

Member Avatar for DMR

Unless you want a fancy-pants infared keyboard you can buy one for under 20 bucks...

Well under $20 at this point in time. Finding one is though, as you sad, the trick.

Member Avatar for jwenting

While cheap keyboards are available I never recommend them.
Cheap keyboards have short MTBF (thus increasing the cost over time of using them) and are uncomfortable (often to the point of being bad for your health) to use (causing RSI).

I used to replace my keyboard several times a year, they wore out that quickly.
Since buying a €100 Logitech almost 3 years ago I've not had to buy a single €20 keyboard, saving me so far well over the purchase price of that more expensive unit.

Member Avatar for Paladine

I have a PS/2 Keyboard. The issue is that the company wants to use the new USB keyboards on the workstations, but we have a bar code reader that requires a keyboard connected to it inorder to work. The problem is the Barcode reader connects to the a PS/2 only keyboard, and we want avoid buy new barcode readers.

Member Avatar for Catweazle

Bung in a USB card. they're about as cheap as a cheap keyboard ;)

Member Avatar for Aneurysm

Well under $20 at this point in time. Finding one is though, as you sad, the trick.

The best part is when the jerkoff at CompUSA wants to sell you a $6.00 two year extend warranty on your brand new $9.00 (before rebate) keyboard.

:twisted: :twisted: :twisted: :twisted: :twisted: :twisted:

Member Avatar for vartotojas

Well I never would have imagined that this was that hard to find. But does anyone know how you would make a USB keyboard work on an old computer that only has ps/2 keyboard and mouse ports?

I got the mouse to work with a USB to PS/2 converter that came in the box, but I can't seem to make the keyboard work? Why is it that the same coverter for the mouse does not work for the keyboard?


Thanks for any help in advance!

use this thing its an adapter for usb keyboards to work on ps2 ports its like $6

Member Avatar for nizzy1115

I think this one got solved last year ;)

Member Avatar for AskVan

Here's your answer... http://www.datapro.net/products/UX2.html
Adapters from DataPro to use a USB keyboard or USB mouse in a legacy PS2 system.

Cheers,:)
Van

Well I never would have imagined that this was that hard to find. But does anyone know how you would make a USB keyboard work on an old computer that only has ps/2 keyboard and mouse ports?

I got the mouse to work with a USB to PS/2 converter that came in the box, but I can't seem to make the keyboard work? Why is it that the same coverter for the mouse does not work for the keyboard?


Thanks for any help in advance!

Member Avatar for Pointman

An adapter only works if the keyboard is ps/2 compatible.

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