Apple ][ + but no Floppies - test-drb@ccmp.vtda.org

12 Dec 1999

On Dec 12, 10:41, Ethan Dicks wrote:

...
  I didn't know that the PERQ used a sync-serial
mouse at TTL levels, but
 are you sure about the PS/2 mice?  After all, there is an adapter you can
 stick on mice to adapt them from 9-pin serial to PS/2 connector, and it's
 only wires, no active components. 
Those which are completely passive only work on certain dual-function mice,
in which the PIC can detect the change -- by detecting the voltage on a
different pin -- and act accordingly, changing the protocol.  In general,
you can't turn any old serial mouse into a PS/2 mouse, nor vice-versa.

To further confuse, there are at least two pinouts for such adapters.

However, there are some active adapters, which themselves contain a
processor (usually a PIC) which will convert the serial protocol into PS/2
protocol.

-- 

Pete						Peter Turnbull
						Dept. of Computer Science
						University of York