[Simh] PDP-8 and OS/8 assembly

[Ethan Dicks]

On Sun, Jun 25, 2017 at 5:50 PM, Bill Cunningham <billcun at suddenlink.net> wrote:
>     I am reading a bit about the machine the PDP-8. 4K fortran I guess was
> used,

That was one option, yes.

> there were 8 "registers" if that's right.

Not sure where this is coming from...

There's the 12-bit Accumulator and its associated LINK (carry) bit.
Some models always have a 12-bit MQ (Multiplier Quotient) register,
some get an MQ when the EAE is installed, and some never get it.
There's a 12-bit Program Counter, and two extended field registers,
either 1-bit, 2-bit (PDP-8/L) or 3-bit (many other models) if the
memory extension hardware is installed (required to have over 4K)

> And 12 bit words.

Yes.

> As far as languages here, is Macro-8 assembly language?

Look for assemblers called PAL (PAL III and PAL8) and MACREL (though
MACREL was a late addition)

>     Is there an assembler available for PDP-8? OS/8 preferrably but tss-8 or
> anything would do?

Plenty of assembler possibilities with OS/8.  I have no experience with TSS-8.

http://www.computinghistory.org.uk/det/8391/PDP8-PALAssembly-Language/

-ethan