7 Jun
2010
7 Jun
'10
4:59 p.m.
Brad Parker wrote:
I already did that. It took a few years, but I only
worked on it sporadically. It currently
boots (in simulation) RT-11, RSTS V4, BSD 2.9 and V6. I have not debugged the split I
& D
but it's there.
If you send me a RK05 image with TSX on it I'll try and boot it in sim.
The last FPGA version I did had no MMU but it did boot RT-11. It had some disk problems
which
I have since corrected. I believe I could synthesize and run the "no mmu"
version pretty quickly.
The mmu version need still needs some work do make 50mhz timing.
I am quite confident that TSX-Plus requires an MMU to run. If you can
confirm,
when I get to testing the TSX-Plus code, I can produce an RK05 image for you
as well.
(b) About how
fast might the FPGA solution be compared to something like a PDP-11/93?
Again, just a rough estimate like 10 or 20 times as fast.
Well, as I said, the no-mmu version runs at 50MHz. I could improve that. The mmu
version probably
won't run faster, mostly due to the 20ns rams on my fpga board.
Any idea why
you did an FPGA implementation of the PDP-8?
back in the day I spent a lot of time on TSS/8. I wanted to run it again :-) And,
I want
to work on cpu's when I grow up.
I also spent a lot of time on RSTS and TSX, hence the pdp-11.
I know the s/w sims are better, but I like hardware and love running h/w simulations.