I have used mouse pieces for two different projects that I can think of.

One past project was a handheld but roll around printer that I helped a guy design. This thing had a replacable 12 dot HP ThinkJet ink cartridge in the front and then two sets of axels and wheels that ran
from front to rear of the device. The wheels were fixed to the axels so that the "printer" affair could track parallel in the left and right direction. I used the modified innards of a Logitek C7 optical mouse to pickup the axel rotation and feed that into a microcontoller inside the product. The thing was called the JetPen. Near as I know it never made it to market.

Another project I undertook was to build wrap-around test boxes that attached to the parallel port of a PC and provide a means for diagnostic software in the PC to be able to send and receive signals to and from every gozinta and gozoutta on the computer including mouse port, keyboard port, COMM port, game port, parallel port (mentioned already), video port, and two joystick ports. These were used at the Samsung computer factory in Korea for doing factory floor system tests and QA tests on the Vendex HeadStart PC/XTs sold during the 80's. The test boxes needed to have cables emanating from them that hooked to all the I/Os on the computers. At the time mouse connections used mini-DIN-9 connectors and such connectors couldn't be had for love OR money. So I was given something like 50 brand new mice with cords. The cords were cut off and used for the test box mouse cables !!

And now you know the rest of the story^TM. Cordless mice of the type left over from the 2nd project I described were the source of optical encoder wheels for some quantity of the JetPen prototypes. Somehow these cordless mice were useless as computer input devices and as such modern day cordless mice must use some other inteface technology.

Michael Karas

Note: Quote (C) Paul Harvey Inc.