On Sun, 31 Mar 1996, Jonathan Short wrote:

> Could someone please tell me what kernel the new ADB kernel is taking the 
> place of?  Or is it just an added on kernel?

The previous ADBtest kernel.

The "ADB" kernels are basically kernels built with patched versions of
the most recent source code.  The normal method for getting keyboard
input involves Mac Rom Glue (MRG), a process by which certain ROM
locations is soft remapped (correct this if it's not accurate) so that
calls to the ADB portions of the ROM code can be called directly without
the intervention of the MacOS.  The problem is, nobody knows the
ROM locations for some of the systems, and in addition, MRG basically
requires separate maps for every single system.

The patched method, continuously under development by John Wittkoski,
essentially scraps the MRG method and instead directly accesses the
ADB hardware in the system.  Because there are far less ADB hardware
designs than systems, this method makes more sense for compatibility
with larger numbers of systems with smaller code and less trouble
porting to new systems.  Currently, ADB is supported using two varieties
of ADB hardware, the Mac II style and the Mac IIsi style.  This includes
the majority of NetBSD compatible systems.

The ADBtest kernels are the only kernels (to my knowledge) that run
on LCIII's.  In addition, the ones that are able to skip the ADB
init code can be used to run in serial console mode on LCII's.
Again, to my knowledge, the standard kernels won't run on LCII's, either.
Not positive, though.

For more information, see

NetBSD/Mac68k ADB Page

Hope that explains it,

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