PDP-11 data and function address spaces (was External ptrs and arrays)

[Henry Spencer]

In article <20642 at mimsy.umd.edu> chris at mimsy.umd.edu (Chris Torek) writes:
>... PDPs came in different models
>and had different operating systems that used different capabilities.
>One of the (somewhat less frequently used) capabilities was what was
>called `split I&D', in which each machine address had to be qualified
>with `instruction' or `data' before it was unique...

Dept. Of Really Fussy Nit-Picking:  relatively few pdp11s, and relatively
few pdp11 operating systems, supported split-space -- Unix on the 44/45/70
was just about the sole example -- but when it *was* available, it got used
*A LOT*.  This is one reason why a stock V7 did not run very well on the
smaller 11s without split-space, although if you munged it hard enough you
could make it go all right.
-- 
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry henry at zoo.toronto.edu