[Simh] pdp11 and unix

[Johnny Billquist]

On 2016-02-26 15:23, Gregg Levine wrote:
> Hello!
> Interesting.
>
> I was only reporting what I remember as to the history of the whole
> example we call UNIX.
>
> And last year at the Vintage Computer Festival East, (Yes Dave W, the
> same one where we crossed paths.), I saw a PDP-11 system having
> finished dumping his program output to a TTY setup. I commented then
> that the instructions shown resembled an 6502 one, I was also thinking
> of the original 6800, but did not say that, and then it wasn't until I
> walked away that I thought of a 68000, but only because I was inspired
> by something I had read regarding the history of what was used in the
> first Mac or its ancestor. And then continuously until much later when
> reason caused Apple to switch to the PowerPC. Let's not discuss the
> decision to switch to Intel.

But then you must have looked at some code that was not PDP-11, or else 
you are very confused about the 6502, or else you are very confused 
about assembler in general.

You are comparing a processor with generic registers, with lots of 
addressing modes, and a fully orthogonal instruction set, to a processor 
that is accumulator based, have rather limited addressing modes, and 
limited combinations of arguments to instructions.

The 6502 have more in common with the PDP-8, I'd say.

	Johnny