Probably this goes in the "I'm building my own... Stupid" category but I can attest that the old adapters from Omniview called the Omniview PS/2 MAC Adapter work very well.
I use 3 of them to hook my B&W G3's and Beige G3's to my Compaq 8 port PS2 KVM.. That way I have a ps/2 PC keyboard and a Microsoft Optical Wheel Mouse controlling the mass of machines under my desk. The newer version of the adapter even supports right click in OS9 which was EXTREMELY strange to notice happen for the first time.
Back in the day when I was developing what would later become part of the Nintendo Wii controller(1995) technology I had an ADB Gravis gamepad with some killy clips off of it and interfaced to the free space joystick. I don't think anything like this free space mouse that was working on my bench was ever released though mainstream. The big thing though is it is exactly the same method you are doing which is great. They used a PIC microcontroller. During debugging I used a small app that sniffed the ADB stream directly in software so I did a LOT of poking around in that data long ago.. Probably not much help now, but it sounds like you are definitely in the right direction.
Good luck!
I use 3 of them to hook my B&W G3's and Beige G3's to my Compaq 8 port PS2 KVM.. That way I have a ps/2 PC keyboard and a Microsoft Optical Wheel Mouse controlling the mass of machines under my desk. The newer version of the adapter even supports right click in OS9 which was EXTREMELY strange to notice happen for the first time.
Back in the day when I was developing what would later become part of the Nintendo Wii controller(1995) technology I had an ADB Gravis gamepad with some killy clips off of it and interfaced to the free space joystick. I don't think anything like this free space mouse that was working on my bench was ever released though mainstream. The big thing though is it is exactly the same method you are doing which is great. They used a PIC microcontroller. During debugging I used a small app that sniffed the ADB stream directly in software so I did a LOT of poking around in that data long ago.. Probably not much help now, but it sounds like you are definitely in the right direction.
Good luck!