Subject: Re: Oh, well. / ADB controllers
To: kr <>
From: Allen Briggs <>
List: macbsd-general
Date: 07/17/1994 23:27:49
Brad should probably address this--he knows a bit more than I do about
the adb situation.

> Why don't we collect some data to determine the scope of the diversity of
> ADB implementations and the scope of the problem ?

As far as I can tell, there are two basic adb systems.  There is the old
MacII-class adb system, and then there is the 68HC05-based.  The second
seems to have several different incarnations/enhancements.  The first
seems to work fine on my Quadra 700 (at least, the keyboard input at the
debugger prompt works beautifully ;-).
Brad has a IIvx, now (don't kill me for admitting this, Brad ;-), and
I expect that he'll either go insane or get it working soon.  The 6805
is a pretty custom chip, I think, but I'm pretty sure that it will be
programmed to be as much like the older system as possible--just because
the MacOS is in the same boat we are--trying to run on all these systems.
Heck, I wouldn't be surprised if the 68HC05 was in the PowerMacs.
However, Apple might've buried it deep in the core of some large IC
that has nothing but an Apple (c) on it...  ;-)

Also, as far as I can tell, you are right on the money that this chip
is in charge of power management on the platforms that have it.  I think
it's also responsible for the various hot-key sequences on the IIsi, but
I won't swear to it.  It's also the interface to several other components,
as you mention.  The difficulty isn't knowing that, but knowing how to
access those functions...


Allen Briggs - end killing - ** MacBSD == NetBSD/Mac **
= Over the years you swam the ocean following feelings of your own [...]  =
== It's a shame to have to die to put the shadow on our eyes.  We don't  ==
=== want to care. Under the bridge. Over the phone. Wind on the Water.  ===