Subject: Re: Apple Desktop Bus and '040s
To: Steven Campbell <Steven_Campbell@magic.ca>
From: John P. Wittkoski <jpw@netscape.com>
List: port-mac68k
Date: 09/20/1996 14:50:18
Steven Campbell wrote:
> 
> I have seen a few other people mention the same thing, but here is what
> I think the problem is with current ADBtest kernels for MacBSD.
> 
> My Centris 650, and Nathan Shaw, among other has mentioned a similar
> prolem.  After ADBReInit is called on Quadra/Centris series, the kernel
> hangs.

The ADBTEST kernels, by their vary nature, DO NOT use the ROMs.

> Now, I'm not a programmer, but I think we have 2 choices.  One, is to
> find out how Apple fixed the ADBReInit problem in their operating
> system, and hack it to fit in ours, or:  Totally bypass ROM calls and
> Reinitialize the ADB ourselves, writing a new routine that talks to
> hardware directly to accomplish the same thing as ADBReInit.

The second thing you mention is exactly what the ADBTEST kernels do.

The ADBTEST kernels have their very own ADBReInit, their own ADBOp,
etc, that MIMIC the behavior of the ROM calls. And the code accesses
the hardware directly, never using the actual ROM code at all.

My best guess for the problem on the 650's is some wierd timing
problem. But I don't have a 650 to test with.

I should have a 1.2 version of the ADBTEST kernel available next
weekend that you can try.

	--John