Not to sidetrack the thread away from the PDP-11, but I thought I’d
mention some recent entertainment I’ve had with the B-em emulator with
another coprocessor emulator – the NS32000 “Tube” running
PanOS 1.4.
There was a VAX Fortran port of the University of Texas text
game “Super Star Trek” (itself an expansion of Mike Mayfield’s
original BASIC game) floating around on the Web a few years
back (with attributions “PRODUCED FOR YOUR ENJOYMENT BY
DAVID MATUSZEK AND PAUL REYNOLDS WITH MODIFICATIONS BY
DON SMITH AND M. KELLOGG”). I got this code back in 2016
from a link on a Web page authored by one Oleg Uryutin of
“Allwards Laboratory”, though that page doesn’t seem to exist
anymore (and was not archived by the Wayback Machine).
Anyway, this code builds and runs on a SimH VAX-11/780
(with VMS 4.7 and VAX Fortran V4.8-276) with no modifications
or difficulties, as might be expected. But after I got
PanOS running I thought it might be fun to try to port the
code using Acorn/PanOS Fortran 77. And – it worked, with
a few gotchas concerning the inter-operability of old-style
Hollerith constants and F77-style “CHARACTER” strings,
which I overcame by “cheating” a bit and linking to some
“helper” conversion routines written in C (with a small
assembly-language interface – the PanOS F77 manual describes the
subroutine calling convention and how to do inter-language calls,
though the examples they give are in Pascal).
