My understanding is that the mouse must support serial or it won't work. Most mice never had this support.

(I recently tried two different adaptors with several Microsoft PS/2 mice and could not find a combination that worked.)

yes the mouse must support both modes in order for this passive adapter to work

PS/2 to Microsoft Serialmouse Adapter Converter / Updated First Post / Firmware Update added

Maybe an Active Device is intressenting for you ?

History repeats. I hear that modern mice are increasingly dropping support for PS/2. You can longer use them with those little green PS/2 to USB adaptors.

I knew it would be too easy to just buy and forget 😀
Matze79, that adapter seems nice, I have to read the whole topic and think about it.

In the early 90's there was often an indication on the sticker at the bottom of the mouse, like this (these work with the simple adapter plug):

This topic comes up about once per year. Anyone run into a USB mouse which supports ps/2 and serial protocols? Double up on the passive adapters 😀

feipoa wrote:

This topic comes up about once per year. Any run into a USB mouse which supports ps/2 and serial protocols? Double up on the passive adapters 😀

I don't think those even exist.

Even if you can find a compatible mouse, using 20-year old ball mice is just unpleasant once you're used to optical mice.

Errius wrote:

Even if you can find a compatible mouse, using 20-year old ball mice is just unpleasant once you're used to optical mice.

Maybe for some people, but not me. I really like my Logitech Mouseman 3-button trackball mouse w/mouse pad. I prefer it to USB optical mice due to the grip.

Koltoroc wrote:

feipoa wrote:

This topic comes up about once per year. Any run into a USB mouse which supports ps/2 and serial protocols? Double up on the passive adapters 😀

I don't think those even exist.

I’ve actually got a prototype of a USB to PS/2 or Serial adapter for mice and USB to PS/2 or AT for keyboards. I’m using a FTDI Vinculum 2 chip for the USB host support, which converts the HID data from a mouse or keyboard to SPI, which an MSP430 microcontroller converts to PS/2. I really need to go back and design a full PCB for it, finish up the software and release it. (So many projects, so little time!)

Does it work without lag, that is, the USB to serial mouse prototype?

Why you need a MSP when you have the FTDI Vinculum 2 ?

The Viniculum already has the Power needed to convert a USB Mouse to RS232 😀 it also has a UART and also can do PS/2 with ease.

feipoa wrote:

Does it work without lag, that is, the USB to serial mouse prototype?

Yes, it worked pretty well. I never quite got the acceleration dialed in, and there were a few firmware bugs that I still neee to fix, but as a proof of concept I found it very useable! If there’s interest in this sort of thing, I’ll finish up the board and firmware and release it.

matze79 wrote:

Why you need a MSP when you have the FTDI Vinculum 2 ?

The Viniculum already has the Power needed to convert a USB Mouse to RS232 😀 it also has a UART and also can do PS/2 with ease.

Because, I hate FTDI’s proprietary dev tools needed to compile for the VINC2. I simply used their pre-compiled USB HID to SPI firmware for it. Also, I’d wanted to make this a multifunction design, with the ability to convert
USB Joysticks and Gamepads to a real game port interface by simply adding a different set of parts to the board. Doing all this is easier with a separate MCU that’s easy to compile for, has open source cross platform tools and only adds $1 to the BOM. Finally, I had considered possibly replacing the VINC2 with a MAX3421E, which is less expensive (though I’d have to deal with Maxim’s terrible sourcing and part life; as a general rule I don’t use Maxim parts because of that, though I also swore I’d never use another FTDI part after FTDIGate a few years back too).