At 17:47 -0800 12/10/09, James Fraser wrote: >Hello, > >Would someone be kind enough to briefly explain the difference between a PC-AT >DE-9 connector and that of the DE-9 found on the back of a Mac Plus? > >I'm guessing that a PC-AT mouse will not work on a Plus because pins 4,5,8, >and 9 on the PC mouse are different. That is, the PC mouse has no way of >generating the appropriate "interrupt" line and "quadrature" line signals in >the first place and, secondly, the pinout doesn't allow for any way for any >such signals to be sent to the Plus > >I ask because I am looking for an alternative pointing device to use on a >Plus. While I like the boxy stock mouse for nostalgia purposes, it's just >*excruciating* to use for a prolonged period compared to later model mice >(meeses?). I would love to be able to use an old Logitech trackball I have >that has a PS/2-serial adapter, but I know it won't work. > >It's the exact "why" that still seems to elude me. Anyone?
Macintosh Family Hardware Reference Addison Wesley 1988 tells all. 1 GND 2 +5 V 3 GND 4 MSE.X2 Mouse X2 quadrature signal 5 MSE.X1 Mouse X1 interrupt signal 6 NC 7 MSE.SW Mouse switch 8 MSE.Y2 Mouse Y2 quadrature signal 9 MSE.Y1 Mouse Y1 interrupt signal There is a decent three-D picture showing the optical lamps, sensors, and timing on page 4-2. It would be a real labor of love to hook up a more modern mouse that has counters internal to it and only transmits a pair of counts over a serial port when asked. The Mac Plus depends on an interrupt every time the aperture disk moves enough to make a photocell change state. The quadrature line is just to show which direction the mouse is moving when the interrupt occurs. Perhaps remounting the internals of an old style mouse in a more pleasing plastic shell? -- --> From the U S of A, the only socialist country that refuses to admit it. <-- -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
