Print

[ried]

I picked up a first-generation Kensington Turbo Mouse 62350 trackball recently, which was made for the Macintosh 128K. It has the same 9-pin D-SUB (DB9) connector as the Macintosh's original Apple M0100 mouse. However, the Kensington trackball features all 9 pins in its connector, unlike the Lisa's A9M0050 mouse and the M0100 mouse, where pin 6 is missing.

Is there any danger in plugging this Kensington's fully populated 9-pin connector into my Lisa 2/10? Will the Kensington's pin 6 cause any potential damage to the Lisa? I'm guessing no, but figured I would ask those more knowledgeable before curiosity gets the better of me. I would like to see this trackball working with Lisa Office System

Pictures here: https://imgur.com/a/djxnspg

[sigma7]

first-generation Kensington Turbo Mouse 62350 trackball... features all 9 pins in its connector, unlike the Lisa's A9M0050 mouse and the M0100 mouse, where pin 6 is missing.

Pin 6 is an input for a third mouse button (which is not supported by any software that I know of). Since the trackball is powered by 5V and the input is tolerant of voltages 0 to 5V, I can't imagine an electronic problem could arise.

However, pin 6 of the mouse port is also connected to pin 25 of the back panel parallel port of the Lisa 1/2 (not connected to the parallel port in the 2/10), and designated "CHK" on the schematic. I believe this isn't used by the ProFile (perhaps it is for use by a parallel printer -- anyone know?), but it might be wise to check the voltage on pin 6 of the mouse port if you have something attached to the back panel parallel port.

If you don't mind opening the trackball, I'd guess you'll find that there is nothing connected to that pin, so starting there may eliminate any worry.

HTH

[ried]

Great insight, as always. Thank you. That gave me the confidence to plug it into the Lisa 2/10 and sure enough, it works just fine under Lisa Office System. The tracking speed is incredibly slow, however, and it wouldn't be practical to use unless that tracking speed can be adjusted.

Here it is in use: https://www.youtube.com/watch?v=oGRYXVdL5j8

[cheesestraws]

For what it's worth, I use the Kensington Turbo Mouse Plus (for the ... Mac Plus) with my Lisa literally all the time, it's my preferred pointing device, and absolutely nothing has gone bang.