Funny enough I’m having a similar problem with a Microsoft Wheel Mouse Optical 1.1a which is usb and ps/2 and it works fine as a usb mouse, but plug it into the Microsoft branded usb to ps/2 adapter I have and get nothing - windows 2000 refuses to see it at all on reboot.

Like you I was under the impression that the mouse detects when it is plugged into ps/2 via the adapter and changes the protocol it uses. So either the adapter is duff or the mouse itself / my ps/2 mouse port is defective (ps/2 keyboard working perfectly though)

As I'm in the market for a new ps/2 mouse (or a ps/2 compatible usb mouse), I'm particularly curious how this thread turns out 😀

Also, can anyone recommend any ps/2 protocol-compatible usb mice that would work under Win98?

There are a few older topics about ps/2 mice:
what are your favourite ps/2 mice?
Mouse Serial VS Mouse PS/2
Modern gaming mouse capable of PS/2?

One mouse that's mentioned is the Logitech SBF96, which has a ps/2 connector and is optical. I kinda want something a little bigger though.

Interestingly, this post mentions using a Logitech MX518 USB via PS/2. I happen to have one of those, so I tried it with my USB/PS/2 connector and it also does not work, even though it lights up just fine and also works when I use it on USB with the Windows 98 USB driver. But of course I also want to use it on DOS. (I guess I'll try finding a DOS USB mouse driver.)
But I just don't get why it isn't working for me when apparently it should work, at least as far as I understand it. I must be doing something wrong, but I'm not sure what.

dada wrote on 2024-04-09, 12:34:

There are a few older topics about ps/2 mice: what are your favourite ps/2 mice? Mouse Serial VS Mouse PS/2 Modern gaming mouse […]
Show full quote

There are a few older topics about ps/2 mice:
what are your favourite ps/2 mice?
Mouse Serial VS Mouse PS/2
Modern gaming mouse capable of PS/2?

One mouse that's mentioned is the Logitech SBF96, which has a ps/2 connector and is optical. I kinda want something a little bigger though.

Interestingly, this post mentions using a Logitech MX518 USB via PS/2. I happen to have one of those, so I tried it with my USB/PS/2 connector and it also does not work, even though it lights up just fine and also works when I use it on USB with the Windows 98 USB driver. But of course I also want to use it on DOS. (I guess I'll try finding a DOS USB mouse driver.)
But I just don't get why it isn't working for me when apparently it should work, at least as far as I understand it. I must be doing something wrong, but I'm not sure what.

Ah crap, seems like your usb-ps/2 adapter is busted?

I use an A4Tech WOP-49 mouse which is USB-PS/2 compatible. Works perfectly in USB or PS/2 mode (with his original USB-PS/2 adapter and several other adapters I have around). Bought it new in the box many years ago, it was my first optical mouse and it still soldiers on.

revolstar wrote on 2024-04-09, 14:05:

dada wrote on 2024-04-09, 12:34:

There are a few older topics about ps/2 mice: what are your favourite ps/2 mice? Mouse Serial VS Mouse PS/2 Modern gaming mouse […]
Show full quote

There are a few older topics about ps/2 mice:
what are your favourite ps/2 mice?
Mouse Serial VS Mouse PS/2
Modern gaming mouse capable of PS/2?

One mouse that's mentioned is the Logitech SBF96, which has a ps/2 connector and is optical. I kinda want something a little bigger though.

Interestingly, this post mentions using a Logitech MX518 USB via PS/2. I happen to have one of those, so I tried it with my USB/PS/2 connector and it also does not work, even though it lights up just fine and also works when I use it on USB with the Windows 98 USB driver. But of course I also want to use it on DOS. (I guess I'll try finding a DOS USB mouse driver.)
But I just don't get why it isn't working for me when apparently it should work, at least as far as I understand it. I must be doing something wrong, but I'm not sure what.

Ah crap, seems like your usb-ps/2 adapter is busted?

Such adapters are passive, there is nothing to break inside them but the contacts. The USB mouse (or keyboard) itself has to know both USB HID and PS/2 communication protocols.

I tried a number of USB to PS/2 converters a few years back and none of them worked in a satisfactory manner.

Sometimes it would sort-of work, but eventually the mouse would stop for no apparent reason.

You're far better off just getting a PS/2 mouse.

revolstar wrote on 2024-04-09, 14:05:

Ah crap, seems like your usb-ps/2 adapter is busted?

I don't think that's the case, I honestly think my mouse just isn't PS/2 compatible like it was sold to me as. I got a set of four adapters (two keyboard and two mouse, but as I understand it they're the same) and none of them work.
Oh well, that's fine, I guess that happens. Good to know it should work the way I was thinking it should work.

For now I guess the mouse works fine through USB, and I'll see if I can get a USB mouse driver working on DOS.

dada wrote on 2024-04-03, 09:53:

Hey all. I've recently bought a USB mouse with PS/2 compatibility to use on my Windows 98 PC, a Kensington Pro Fit Full-Size Mou […]
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Hey all. I've recently bought a USB mouse with PS/2 compatibility to use on my Windows 98 PC, a Kensington Pro Fit Full-Size Mouse.

However, I think the information on the site where I bought it might have been wrong or something, because when I attached it via a USB-PS/2 converter it doesn't work. The mouse itself works on another computer, and when I connect it to the PS/2 converter it's powered on just fine, but it doesn't seem to do anything. Even though the mouse is sold as being PS/2 compatible on the shop where I bought it, I can't find any indication that it actually is PS/2 compatible on Kensington's own site. So I think I actually maybe just bought a USB only mouse by accident.

But just in case I'm just being stupid, can someone tell me if a USB/PS/2 compatible mouse should just work in Windows 98 without needing any drivers? I actually don't have any other PS/2 mouse to test it with. But my understanding is that some mice have USB and PS/2 protocol compatibility and when that's the case you should be able to use a converter and it should just work, right?
Thanks for your thoughts 😀

EDIT: Looks like my memory is playing tricks on me, please disregard what I wrote below about how a PS/2 compatible USB mouse detects being connected through a passive adapter.

Maybe I missed something, but what leads you to believe that the mouse you linked to has PS/2 compatibility ? I don't see anything about that in the description on the site or the manual .

That being said, modern USB mice can have non-disclosed PS/2 compatibility.

Additionally, to clear things up the overwhelming majority of USB to PS/2 mouse adapters are passive AND they ARE NOT all wired the same way. AFAICR, those meant for Logitech USB mice are not interchangeable with those meant for Microsoft mice. There maybe other variations too.

If a PS/2 compatible USB mouse is not paired with a compatible passive USB to PS/2 adapter, it will not work on a PS/2 mouse port.

Incidentally, the way these passive adapters are designed to work is typically by connecting 2 pins on on USB mouse together or possibly by connecting a specific pin to ground (not too sure which it is from memory), which tells the mouse to switch to PS/2 mouse and redefines to by redifinig remaining pins on its USB port to PS/2 compatible signals. Consequently, for it to work with a given mouse, a USB to PS/2 passive adapter must connect together or to ground the proper pin(s) and connect each of the remaining USB pins redefined to USB to the proper corresponding PS/2 pins.

Then there are active USB to PS/2 converter that convert any USB mouse for PS/2 use. These are quite rare AND much more expensive. They are also not reversible. Active converters to turn a PS/2 mouse into a USB one are common and inexpensive (but not all without issues) and ARE NOT reversible or interchangeable with the aforementioned active USB to PS/2 converter that convert any USB mouse for PS/2 use.

Here is an example of a "modern" (2017) USB mouse with undocumented PS/2 compatibility that happened to work with one of the passive adapters thactive USB to PS/2 converters that I own:
USB mice still available in retail stores/online with PS/2 protocol compatibility

In case anyone's still interested, I got the Cherry Electronics M-5400, it comes with a ps/2 adapter and works fine with my KVM switch both under Win98 and WinXP. What's also important is that it doesn't only come in black, but also in white and grey, so like y'know, retro-friendly colors! <3 😀