View Full Version : USB to PS/2 (mini-din) connector problem

Billy T
12-06-2011, 11:43 PM
Hi Team

Having successfully rehabilitated my old W2K computer, I've now hooked it up to my KVM switch so that I can share the keyboard and monitor. My new computer has a USB mouse and the old one has a PS/2, so at present I am using separate mice.

Today while digging around in my misc-bits box I came across two USB to PS/2 adapters, one for keyboard, one for mouse, so I thought 'whoopee-doo' I'll plug the USB mouse into the KVM switch via this adapter, hook up the PS/2 socket on the new computer to the switch and be able to share one mouse between the two.

Well, that was the theory, but when I booted my main computer the mouse cursor was frozen. Plugging it back into a USB socket restored normal service, so was there something I should have done to tell the computer that I was shifting from USB to PS/2?

I haven't tried the old computer yet, as there is no point if I can't get the new one going via PS/2.

Any ideas?


Billy 8-{)

13-06-2011, 09:33 AM
First question I'd ask is whether your USB mouse would work at all through the adapter?

As I'd imagined it, those adapters were fairly common back when USB was the emerging standard & PS/2 was prevalent, but fast-forward to today, PS/2 is pretty much dead. So why would a manufacturer bother to include special circuitry/firmware in the mouse to handle the unlikely event that you'll be plugged into a virtually nonexistent port?

I have a couple of old Microsoft mice around that will handle those adapters (were supplied with them), but I'd be quite surprised if any of my newer mice would (if I could find a PS/2 port to test with, I'd let you know...).

Speedy Gonzales
13-06-2011, 09:58 AM
I wouldnt bother with those adapters. I've got about 3 of them. And they've never worked

13-06-2011, 10:21 AM
I've used these adapters with a KVM too and found Windows didn't like them after it was installed, but if you installed Windows while using one it worked fine.

This was back in the Win9x/Win2K days. Its possible XP/Vista/7 or newer KVMs behave better.

Billy T
13-06-2011, 01:00 PM

I figured it was probably a computer age/generational thing. I don't remember even getting these adapters, so they must be fairly old.

I guess the next question is whether there is any way to share/switch the mouse between the two computers and I'm thinking that could possibly be achievable. I have a redundant USB hub that might even do it, or I can build a simple switch.

It is not by any means a critical or essential requirement, I'd just prefer to work with one mouse only because when working with one screen and keyboard I occasionally forget which mouse I should be using.


Billy 8-{)

13-06-2011, 01:04 PM
Paint them different colours, so that each mouse, keyboard combo has a matching paint job to each screen

13-06-2011, 01:32 PM
Sometimes reboot a couple of times and it comes right.
Otherwise, at the PC end, try a 2xPS/2 to 1xUSB adaptor (Computer Dynamics) and trick the PC into thinking you plugged USB mouse in directly. (Assuming your KVM switch ends up with PS/2 connectors)

13-06-2011, 04:34 PM
Sometimes reboot a couple of times and it comes right.

I'd agree with him. That's often happened on machines where it doesn't detect a PS/2 mouse right after I plug a USB one in.

Billy T
13-06-2011, 07:29 PM
OK, I'll try the multiple reboots. The KVM switch is PS/2 for mouse and keyboard by the way.

I have a green adapter and a grey adapter, and I just noticed that while green is typically the colour of a PS/2 mouse plug, so I was using that the green adapter, which is unlabelled, but the grey one says 'Mouse" so I'll swap to that. My bet is that they are identical, but what the heck, it is worth a try.


Billy 8-{)

Billy T
13-06-2011, 08:50 PM
Success! :D

Changing the adapter, checked all the plugs, then rebooting just once saw both computers running fine with the USB mouse connected to their PS/2 sockets via the KVM switch. W2K appeared to have no problem sorting a mouse driver because it was up and running right from the off. It makes swapping between computers virtually seamless.

Why do I bother to keep the W2K box going? Well, I have several old legacy (read DOS) technical programs that either operate instruments or process their data that don't play nicely with XP, one won't start up at all, and I suspect they will probably not even look at the latest Win OS.

When that day comes, I'll run virtual machines but I aim to get VM experience before I actually need it and in the meantime this set up works just fine.


Billy 8-{) :thumbs: