Re: Mouse using graphics programs?

[Roger Johnstone <rojaws@es.co.nz>]

In <jOOcnfO59Ksuv5-iXTWJjw@comcast.com> Bill Garber wrote:
 
>> Don't think it's that simple... I have a //c mouse that doesn't work 
>> on my //c, but my IIe mouse does. Both work on the IIe and Mac Plus.
>> Whether it matters or not I don't know, but if you look at the model
>> number of the mouse some start with "A2" and some with "M" -- 
>> presumably this would indicate Apple 2 or Macintosh. I've always 
>> suspected the problem (in my case) is with the mouse port on the //c... 
>> since it doubles as the game port maybe there's bug.
> 
> Possibly ones with an A2 number will work but I also
> was under the distinct impression that since the IIc's
> game port doubles as a mouse port that the mouses
> were wired differently. All I know for sure is that all
> the M0100 mouses I have don't work and all the ones
> marked IIe don't work and all the ones with IIc on the
> label do work. So, IMHO, if you get one that is marked
> IIc you run a better risk of it working. I also read about
> a hack where you add a resistor or diode, can't remember
> which now to the IIc motherboard and it allows either
> one to work. There is also a paddle thing you can do, but
> I'm not so sure I would mess with that. ;-) I now have 2
> IIc mouses that work, and 3 IIc's so I'm looking for one
> more. Very little I need now but much more WANTS.

On a Mac's mouse socket pins 1 and 3 are labelled as ground, and I 
assume the Apple mouse card is the same. On the IIc mouse/joystick 
connector pin 1 is used for Mouse ID (mouse) or pushbutton 1 (joystick) 
and pin 3 only is ground.

On the third-party mouse I have pin 1 is connected directly to pin 3. 
This mouse works with my IIc, and is advertised to work with a Mac and 
Apple II mouse card as well. So it would seem for the IIc to work with a 
mouse, the mouse has to pull pin 1 directly to ground. I suspect that 
the early mice didn't have this link, and it was only added after the 
Apple IIc was released.

A quick test with an ohmeter will verify if pins 1 and 3 are connected 
in the plugs of the mice you have that don't work, versus the ones that 
do work.