Re: ADB mouse compatibility on IIgs?

[Rubywand <rubywand@swbell.net>]

Liam Busey writes ...
> 
 ....

> I also have a Microview PS/2 to ADB converter. All the mice I've tried seem
> to work pretty well but the keyboard  will only work correctly on a ROM 3
> IIgs. Must have something to do with the ROM 1's early implementation of
> ADB.

 ....

     Most likely. The main switchover happened when Apple introduced the ROM-01
motherboard in 1987. That left thousands of ROM-00 motherboard IIgs's which had
been upgraded to "ROM-01" but still had the original ADB IC's.

     Evidently, Kensington designed and tested it's TurboMouse using the newer
IIgs. For sure, they were surprised when reviewers reported the product would
not work on the ROM-00 boards upgraded to ROM-01. (Seems like I ended up with
three TurboMouses before we agreed that, whether or not the ROM-00 board ADB
IC's always worked correctly, they were just plain incompatible with
TurboMouse.)


     The problems with bad ADB chips on some of the early IIgs's became
legendary as did the system crash error message with the 01 ROM installed:
"FATAL SYSTEM ERROR 0911".



Rubywand