NULL pointers

[Guy Harris]

> > 11/40 or 11/45?  The 11/40 didn't have separate I&D space, so the C
> > startup code should have appeared at location 0, unless you were using
> > something other than C.
> 
> But what about sysfix?

"sysfix" made split I/D space kernels out of kernels linked with "ld"
(I had all my V6 experience on non-split-I&D space machines so I don't
remember too much how it worked).  It wasn't used on non-split-I&D space
machines, nor was it used on user-mode code.

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy