Hi all,
At the time I've released my DG NOVA in Verilog I was also working on a
PDP-1 in Verilog. Since I haven't
touched the thing for quite some time I've decided to just release it
before it catches dust. So far it can
execute all kinds of programs, limitation is that they may not use IO as
I haven't implemented the latter yet. (So essentially the same state as
my DG NOVA implementation)
It also supports optionally some PDP-1D features in the OPR and SKP
instruction groups. Interrupts are implemented but untested. I'm not
sure in which state I left the IOT controller if it works then both SBS
and SBS16 might be usable.
TL;DR: https://github.com/Jside/pdp1
The RCA110 was the project I was working on before I started the DG
NOVA, it can execute some instructions but there is to much ambiguity in
the reference manual on bitsavers in some cases which led
me to abandon it. Especially since there is no software to cross-check.
So for reference you can get it here:
https://github.com/Jside/rca110
I wanted to mess around a bit with Chisel (a new HDL language used by
the RISCV project) so here
is the start of a CDC160 (currently only the instruction decoder):
https://github.com/Jside/cdc160
I've also uploaded my DG NOVA to Github: https://github.com/Jside/nova1
MC14500B anyone? http://janadelsbach.com/soft/mc14500b.tar
I will occasionally continue working on both the NOVA and PDP-1 (and
maybe CDC160?). Also pull requests are welcome.
As is obvious I *really* like implementing old computers in HDL
languages but I always get stuck
around IO since for any kind of flexibility as with an emulator I
essentially would need to write a bus wrapper so that a (soft-core)
processor executing Linux running an IO server could handle i.e. hard
disks and magnetic tapes and that's I think really not worth it. So I
might just go over and contribute to an emulator/simulator like SIMH if
I'm in an must-implement-an-old-computer/processor mood ;).
Regards,
Jan
