IBM RT-PC available

I have -- somewhere -- an IBM optical mouse. I know nothing about it other than it's 3-button, and IIRC the cable ends in a DE9 connector. Inside is a microcontroller (8051). and not a lot else. I think I once traced out some of the wiring back to the DE9 and came to the conclusion tha the microntroller ran between the -ve supply line and something 5V positiove wrt that and there was a transsitor buffer to make the output RS232-like. <fx : ARD looking on shelf of computer bits> Amazingly I've found it. The label on the bottom says : IBM MOD 5277-1 MODEL MOUSE MFD BY SUMMAGRAPHICS CORP FAIRFIELD CT USA It also says FCC IDD : BY78SDMOUSE I am not going to type out the FCC notice or attempt to reprocude the barcode, but under the barcode is the stirg 71B35021819109 The connector is a DE9 with pins 1 and 3 mising Philip, if you think this will work on your 6150, you are welcome to try it. I don;'t have the mouse pad (and as I said it's optical, from the time when you needed a special mouse pad for optical mice), and it is, of course, untested..