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Do PS2-to-USB Keyboard Adapters Work?

ewhac asks: "Recently, I was charged with the mission of obtaining a particular small external USB keyboard, for use on a Win2K laptop. However, when the USB version proved unavailable, I obtained the equivalent PS/2 version and an inexpensive PS/2-to-USB adapter. Should have been cake... Except that it didn't work. Win2K failed to see the keyboard, claiming instead to see an unknown USB device. A different USB adapter didn't help. A different keyboard didn't help. Trying on a different computer didn't help. Googling my eyes out for several hours looking for answers didn't help (although I found a few people with the same question). So I thought I'd beseech the Slashdot crowd and ask how many people have had success using legacy input devices with small, inexpensive PS/2-to-USB adapters?" "Here's the keyboard in question. Here's the first adapter we tested, and here's the second (ignore the picture; it's wrong). Several things about this experience have left me very confused. Keyboards and mice are simple manifestations of the USB HID (Human Input Device) class, and Win2K ships with a fairly complete set of HID drivers -- plugging in a keyboard should (and often does) Just Work. Hence, these adapters are sold without drivers. Further, the PS/2 electrical and logical specifications are older than dirt, and well understood. USB is also very well specified. So building an adapter should be a very straightforward effort, with little room for surprise or failure.

And yet, the damn thing refused to work. All PS/2 keyboards tested worked fine when connected to native PS/2 ports. All computers tested recognized all other USB devices when plugged in. But no matter what we did, we couldn't get any system to recognize any PS/2 keyboard plugged into these PS/2-to-USB adapters.

As the evening wore on, I started to wonder just how many other people had experienced this perplexing situation, and how they resolved it. The makers of these adapters wouldn't knowingly sell non-functional merchandise, so I assume that somehow these things can be made to work. What I'm wondering is what special conditions, if any, are required to get them to work."

2 of 84 comments (clear)

  1. Read the further description... by NecrisRex · · Score: 5, Informative

    OK, I'm pretty sure that that adapter doesn't provide any USB interfacing beyond what's there in teh keyboard. You probably would need the adapter for sale here: http://www.centralcomputer.com/emerchant/itemdetai l.asp?item=MISCABUSBW3R Linked from that same page. A USB device is a smart device with a chip that discusses what it is with your computer. A PS/2 keyboard is NOT. The more complete adapter probably fills in the gaps with a USB device chip that identifies itself as a PS/2 port. Later, Necris P.S. Good luck with your setup!

    1. Re:Read the further description... by DavidTC · · Score: 5, Informative
      Someone mod this guy up. This is exactly what happened. I have a PS/2->USB convertor, and it's a real convertor that will convert a PS2-only keyboard to USB (or, incidently, a PS2 mouse. I think it can even handle a splitter and do both.), and it cost 15 bucks. It clearly has circuitry in a little bump in the middle.

      What the goober that posted purchased was a plug adapter that just makes a dual PS2/USB keyboard physically fit into a USB socket and switches the internal keyboard circuitry to use USB. This will obviously not work on a PS2-only keyboard, as they have no USB circuitry.

      I'd blame the store for selling them, but it clearly says that it won't work without the correct keyboard. And I guess someone has to sell replacements if you lose them.

      --
      If corporations are people, aren't stockholders guilty of slavery?