On Sat, 3 Jul 2021, Anders Magnusson wrote:
Hi,
some time ago I ended up in an architectural discussion (risc vs cisc
etc...) and started to think about vax.
Even though the vax is considered the "ultimate cisc" I wondered if
its cleanliness and nice instruction set still could be implemented
efficient enough.
Well, the only way to know would be to try to implement it :-) I had
an 15-year-old demo board with a small low-end FPGA (Xilinx XC3S400),
so I just had to learn Verilog and try to implement something. And
it just passed EVKAA.EXE:
<snip>
Very cool stuff.
Just a thought, if you were to implement this on the DE10-Nano board
with the MiSTer framework[0], you could add to the growing list of
'retro'
systems that has a pretty sizeable community around it.
A full MiSTer setup isn't as cheap as you're indicated the board you're
working on is (~$300 vs $30 USD), but in the MiSTer environment,
we've already got dozens of old systems in various levels of
re-implementation, from the Acorn Archimedes to the ZX81. There is even
a 32bit Sparc implementation being worked on (not on that wiki page, but
can be found elsewhere[1]). It boots SunOS, NetBSD, Linux, and even
NextSTEP, though that last one is still a bit buggy.
So far, the only DEC system implemented on it has been the PDP-1. VAX
would be an awesome addition to the list.
I'm not involved with the project other than it's been something I
started playing with during the COVID lockdowns last year.