att & osf

[Rick Adams]

> >By the way, code which dereferences NULL pointers hurts some AT&T hardware too
> >(i.e., the 3B20, which doesn't have a 0 byte at location 0 in the process
> >space).  Somehow, several releases of System V have been brought up on it...
> 
> If I'm not mistaken, the 3B20 may not have a 0 at 0, but it does permit
> accesses to location 0.  And yes, there are things in System V that break
> if this isn't possible.

If you look at the source for tabs in Sys V.2 you will see that
*0 on a 3b points to "f(". After all, isn't this the "portable"
way for check to see if a pointer is null?

	if (err <= 0 || columns <= 0 || strcmp(set_tab,"f(") == 0) {

(They finally fixed this in Sys V.3)