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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."
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."
After you start working with at least 20 computers daily you'll soon learn that nothing in windows just works all or even in the 90's of percent of the time.
The easiest thing to do here would be to think outside the box. Run the mouse off the usb port instead and run the keyboard off the native ps2 port.
Both of those things look like they're simple adaptors that just change the plug from one to the other. Even the first link you mention says, "***IMPORTANT NOTE***: 10160 is the adapter ONLY, without chips and any software. If you do NOT have the related chips and software on your computer, we strongly recommend you to by the whole converter"
The one in that link looks more substantial and looks like it'll actually have some circuitry inside it, rather than just changing the pinout.
The very clear description of the first product reads....
Application: USB ADAPTER for USB A Type Male to Mini Din 6 Pin Female ***IMPORTANT NOTE***: 10160 is the adapter ONLY, without chips and any software. If you do NOT have the related chips and software on your computer, we strongly recommend you to by the whole convertor
Did you *buy* the whole convertor, or do you have the chips & software required to translate PS/2 -> USB already in your PC ( pretty damn unlikely! ).
The outpost convertor looks to be the same dealie.
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I don't know the technical details, but I can say that adaptors like this consistantly work great, while adaptors like this don't work at all.
As far as I can tell, since the adaptors which work are always larger, I assume they have extra electronics inside so they can communicate with the USB port more intelligently.
If someone else knows the technical details of how this works, I'd love to hear about it.
There are two types of differences: the pinout and the protocol. If you have a PS/2 only keyboard, you need both--a pinout change and a way to speak the protocol. If you have a PS2 & USB-compatible keyboard that only has a PS/2 plug, then you can use the small, pinout-only adapters because the keyboard will be smart enough to sense and adjust the protocol appropriately (though some older ones use a switch).
bp