IIgs mouse replacement problem

[pitz <pitz.wong@gmail.com>]

I have wanted to replace my IIgs mouse and integrate it with my KVM
("K-M" is probably a more appropriate term with the setup I have).
I've got a PS/2-style keyboard and optical mouse, and use an IOGear G-
CV160 PS/2-ADB converter hooked up to my KVM switch.

Connected to a Mac LC475's ADB port, there aren't any mouse-related
issues.  But connected to a IIgs' ADB port, it gives an erratic mouse
behavior.  Movement of the mouse will sometimes register a "click" in
GS/OS.  So depending on where the mouse cursor is, the result of
moving the mouse ranges from benign to disastrous.

I initially thought it was either because of the PS/2-ADB converter or
the KVM.  I eventually dug out an old Mac teardrop mouse and connected
it directly to the IIgs, and the mouse problem is still there.  The
original IIgs mouse does not exhibit the problem.

Googling for info, I read up on the (in)famous "Space Aliens Ate My
Mouse" TechNote for ADB devices.  It seems that there was at least one
revision to the "Apple Mouse Protocol".  There is an "Extended Apple
Mouse Protocol" which I am suspecting is what's used by modern ADB
mice hardware (including the old Mac teardrop mouse).  TechNote is
dated 9/1998.

Is GS/OS expecting the original "Apple Mouse Protocol" from the
device?  Can it be patched?

/Peter