24 Sep
2011
24 Sep
'11
10:43 a.m.
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.
Hang on a second. Logically, a 'PS/2 keybaord' is one that works on a
PS/2 computer. A PS/2 mouse is simularly one that works on a PS/2
computer. There is no reason to assume that the interfaces must be similar.
My PEEQ has a keyboard, which I could logically name a 'PERQ 2 keyboard'.
And it has a pointing device, which I could logically name a 'PERQ 2
mouse' (although it's really more of a small digitisng tablet about the
size of a ouse mat with a puck that's shaped like a mouse). They both
plug into DIN sockets on the monitor. Are you claiming that the 'PERQ 2
keyboard' interfac and the 'PERQ 2 mouse' interface must be simuilar.
Because I can assuue you they are nothing of the sort.
In the case of the PS/2 keyboard and PS/2 mouse, the interfaces _were_
similar.Each hidirectional clock line and a bidirectional data line. the
very low level protocol - -how to send bytes between the keyboard/mouse
and the computer is much the same. The differnce is in what bytes you can
send and what they mean.
There were never AT-interface mice - so *something* in there is different.
Only because no PC/AT keybaord interface microcontroller exepcted to talk
to a mouse. There is nothing to stop them existing.
-tony