Infocom on PDP-11

[Paul Koning]

>>>>> "woodelf" == woodelf  <bfranchuk at jetnet.ab.ca> writes:

 woodelf> Allison wrote:
 >> Decmate II/III uses 6120 (PDP-8 with EMA).  There is no *nix for
 >> the PDP-8 and OS278 is common.  FYI: VMS runs on VAX(32bit) and
 >> Alpha(64bit).
 >> 
 >> If you can fit the game format into a 32Kword 12bit machine it's
 >> possible.  Generally speaking there isn't a C compiler for PDP-8 I
 >> know of and the 4k paged addressing and very minimalist
 >> instruction set would be an interesting challenge. I've seen
 >> Fortan, Focal, Basic and even algol on an 8 but never C.
 >> 
 >> 
 >> 
 woodelf> The lack of local variables makes C very dificult.

Huh?

You're confusing the lack of a hardware stack with the lack of local
variables.  They are not at all related.

The IBM 360/370 series doesn't have a stack, and some of its
restrictions are vaguely PDP-8 like.  Nevertheless, GCC supports C
(and C++) quite nicely on those machines.  

For that matter, Algol had local variables long before C was invented,
and as you pointed out, there's an Algol for the PDP-8.  (Then again,
that's not a true compiler -- it compiles to an intermediate form that
looks very much like a subset of the Burroughs 5500 instruction set.)

And Unix originally appeared on the PDP-7, which you can describe
quite reasonably as an 18-bit superset of the PDP-8.  (That's
historically nonsense, but as a description it fits.)  Did C exist
back then, or did that wait until Unix was ported to the PDP-11?  I
don't know.

Finally, CDC 6000s don't have a stack either, but the first Pascal
compiler ran on that machine.  Implementing a stack on a non-stack
machine (or non-stack language like Fortran-II) is a nice elementary
Exercise for the Student.

	   paul