On 24 September 2011 03:06, Chuck Guzis <cclist at sydex.com> wrote:
  On 24 Sep 2011 at 2:20, Liam Proven wrote:
  I have no clue about the signalling level stuff,
but there were also
 PS/2 mice; same physical socket, different signalling. Mice wouldn't
 work on keyboard ports and keyboards wouldn't work on mouse ports,
 until the very end of the lifetime of the standard.
 There were never AT-interface mice - so *something* in there is
 different. 
 The lack of interchange betwen the mouse and keyboard is largely a
 function of the microcontroller attached to the connectors. ?It was
 not at all uncommon to see 90's "clone" PC keyboards and cases with
 two punchouts in the connector area; a large one for the full-sized
 DIN connector and a small one for the (PS/2-type) mouse. ?The
 keyboard connector was downsized when the ATX cases and boards came
 out. 
Yup.
  But the "PS/2 mouse" didn't originate
the use of the mini-DIN
 connector. ?That belonged to the Microsoft bus mouse, aka the
 "InPort" mouse in which the mouse was pretty much all passives and
 the interface board had a dedicated microcontroller. 
True - but it is completely incompatible with PS/2 mice.
  I've still got a pretty good pile of RS232 mice as
well as a couple
 of trackballs. ?Many versions of Windows are smart enough to detect
 and configure the serial mouse, even if a PS/2 mouse is also
 attached. ?Makes for some interesting two-handed pointing... 
Yeah, me too. It might be of use come Windows 8, which supports
multitouch throughout the new Metro interface. :?)
Of course, you can also just connect as many USB mice as you want...
--
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