Mackinlay, Patrick <patrick.mackinlay@kjv.com.au> said;

> I'm interested in working toward a port of NetBSD to the Intergraph Clipper
> platform. I'm some way away from that point yet, but I'm learning what I can
> about NetBSD before tackling the job. What I'm really interested in knowing
> right now is, which is the "best" port for me to duplicate and modify? By
> "best", I guess I'm talking about "most similar", and in order for anyone to
> answer that question, I'll need to provide some information about the target.

I'd suggest NetBSD/mipsco, a modern NetBSD port for MIPS Computer
RC3230 system.  It has fairly similar devices inside.  All of device drivers
which your machine has are already written by others in MI form or MD
form.  So little hardship is expected before useful working devices.
The developer, Wyne, was a quite quick learner.   He has grasped
"the art of NetBSD" essense in short time and implemented the relatively
small port in a sane way.  Old NetBSD ports, like i386, pmax, mac68k and
others, are suffered from insanity code or old ones. Their implementation
could be much cleaner if they were reimplemented from vacum compositing
modern structuring elements of modern NetBSD.

I'm personally interested in pmap module for the processor.  I have local
pmap codes for MIPS and m88k which are too inmature to commit NetBSD.
During the development efforts, I've learned much about NetBSD pmap
logics.  Probably I would be able to guide you on the aspect.

I could provide more details of porting, step-by-step and file-by-file
explanations.   If you're a sort-of kernel guy and you have not get touch
with following two books, I recommend them highly.

Uresh Vahalia, UNIX Internal, The New Frontier
Curt Schimmel, UNIX Systems for Modern Architectures

They have astonishingly excellent contents. 

Tohru Nishimura