PDP-8 stuff - test-drb@ccmp.vtda.org

8 Feb 2012

On 2012-02-07 14.03, ben <bfranchuk at jetnet.ab.ca> wrote:
...
  On 2/6/2012 7:00 PM, David Griffith wrote:
  >  On Mon, 6 Feb 2012, Eric Smith wrote:
 >
> >>  Ray Arachelian wrote:
>> >>>  (Waiting for the guys that ran real UNIX on a PDP-8 to show up and
>> >>>  say they rode T-Rex's to school.)
> >>  No, the PDP-8 Unix is one of the modern ones. Only the guys that ran
> >>  really early Unix rode T-Rexes.
 >  No No No ... that was T-nix followed later with U when the programers could
 club meat, build fire and recite most of the Alphabet*. 
:-)
There is no Unix for the PDP-8. There are, however, several timesharing 
OSes, and yes, people did use PDP-8s in such environments.

...
  You seem to have a few 6502  unix style systems hacked
together on the web. 
Crazy, if true.

...
   >  So, does
anyone have a record for oldest or weakest computer running
 >  Unix? The Z80 definitely did it. Maybe the 8080 could. I don't think the
 >  PDP-8 could. I've been trying to figure out if the PDP-8 could handle C,
 >  and the answers I get range from "I don't know" to "Definitely
not".
 >  Something I'd really like to see is a Z-machine running on the PDP-8. 
That came up a few years ago, the pdp8 does not have ample memory to handle
 Z-code.
 Ben.
 * No, not in Octal. 
I'm sure I could do it. A Z-machine implementation really does not need 
*that* much memory. You'll need a field, possibly two, for the Z-machine 
itself. After that, the rest of the memory can be used for the storage 
inside the Z-machine, and then cache for the code, which needs to be 
paged from secondary storage. No different than any Z-machine for any 
micro in the 80s.

As for PDP-8 handling C. I'm not sure I understand the question. You can 
definitely have a C compiler that generates code that will execute on a 
PDP-8. Having a C-compiler running on the PDP-8 would be quite an 
effort, however. But it can be done. You just need to split the process 
up into many passes, with careful design. And it might take a very long 
time to ever compile a single file.

	Johnny