Re: IIGS ADB mouse - Can it be adapted to IIe/IIc use??

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

In <bklpq4$57r$1@freenet9.carleton.ca> Michael Black wrote:

> Given that I thought the mouses for the earlier Apples were on the 
> level of the original Mac mouse, no.  ADB, like serial and PS2 mouses 
> for the IBM world, send out serial data.  The earlier computers are 
> looking for a a number of discret lines, carrying such things as up/
> down, left/right, and their 90 degree shifted complements, and button(
> s) press.  The only way you could get a useful mouse out of an ADB 
> mouse connector would be to throw in a computer to do the conversion.
> 
> But, if you really want to mess the ADB mouse, likely you can find
> the needed signals inside the mouse.  You'd bypass the IC in there,
> and bring out the signals directly from the button swith, and the 
> outpus of the 4 optocouplers, plus feed some voltage in to power the 
> optocouplers. I once did this with an IBM type serial mouse, bringing 
> out those signals to make a spare mouse for my Mac Plus.
>
> In other words, the ADB mouse is a superset of what's in a non-ADB 
> mouse, and if you are willing to modify it, likely you will get a 
> working mouse.
>
>   Michael

The old Apple mice also have a buffer or voltage comparater chip inside 
them, but I think that's just so the optoswitches produce a nice square 
output, perhaps for hysteresis too.

On a related note ;-) I sell a PS/2 to Apple mouse converter on my web 
site. An ADB to Apple mouse converter could be done the same way.

-- 
Roger Johnstone, Invercargill, New Zealand

PS/2 Mouse Adapter for vintage Apple II or Mac
order at http://vintageware.orcon.net.nz