9 Apr
2010
9 Apr
'10
6:07 a.m.
Martin Goldberg <wgungfu at gmail.com> wrote:
Someone from the IGDA-Preservation group is in the
process of
transferring old DEC game code printouts in to text files, and was
wondering if any one from the list knew if there was a PDP5 emulator
(as a bunch of this is PDP5 in origin)?
He may also require assistance in checking some of the assembly, as
the printouts and copies are not always clear enough to read
accurately.
Any help would be appreciated, and I'll pass the info on.
Depending on the code, it might be runnable on a PDP8.
The main differences between the PDP5 and PDP8, as far as I can
remember, is that the PDP5 keeps the PC at address 0, and stores the old
PC at address 1 when an interrupt happens, while the PDP8 have the PC as
a separate CPU registers, and stores the old PC at address 0 when an
interrupt occurs.
And some (combinations of) OPR instructions don't work on the PDP5. But
that should not be a problem if you just take the program to a PDP8.
So, unless the program in question needs interrupts, or play directly
with the PC, I believe it might run on a PDP8.
Johnny