[HECnet] PDP-11/70 on FPGA

[Zane H. Healy]

On Tue, 10 Aug 2010, Brian Hechinger wrote:

On Tue, Aug 10, 2010 at 06:50:32AM -0400, Paul Koning wrote:

http://opencores.org/project,w11
Think that can run RSX/RSTS?
I'll have to take a look... a second reason to get an FPGA eval board...

It only runs on two boards, but at $100 for one, it's not a bad price, really.

Hmmm, that isn't a bad price.

Yes, it should run most software just fine.

Excellent.

I'd personally be the most interested in RT-11 and RSTS/E.   From the sound
of things, RT-11 at least should work.

2) Small disks. Only RK05 for now, and no plans for MSCP at all. While
future massbus is cool, by todays standards, fixed size, rather small
disks, are not that useful.

Yes, this I can agree with, most definitely.

Non-MSCP disks can be done in logic; MSCP has always been implemented as firmware running on the storage controller.   Presumably you'd want to do likewise here.   That's certainly possible, with the help of an embedded processor inside the FPGA.   Then you'd have to implement the MSCP firmware, which is a fair chunk of code.   (I don't suppose anyone has the UDA50 firmware available?   Then all you'd need is an FPGA model of the hardware, which would be easy by comparison.)

I *think* I've got a UDA50 laying around (or know someone who does), what would
be required to extract the firmware from it?

Even on the PDP-11, an RK05 is a bit tight.   In fact it means that running
any semi-current OS would be challenging.   I don't believe I have a UDA50,
but I'm pretty sure there is a KDA50 in my MicroVAX III (yes, I know that is
Q-Bus rather than Unibus).

Yes, I agree, the backend server bothers me a bit as well.   I've love to have
something I could plug a CF card and an ethernet cable into and be done with
it.

Considering that I can plug SD cards, and an ethernet cable into my
Commodore 64, I couldn't agree more.

Zane