PDP-11/70 Boards

Josh Dersch derschjo at gmail.com
Mon Nov 29 15:12:27 CST 2021

On Mon, Nov 29, 2021 at 1:06 PM Ethan Dicks via cctalk <
cctalk at classiccmp.org> wrote:

> On Mon, Nov 29, 2021 at 3:19 PM Henk Gooijen via cctalk
> <cctalk at classiccmp.org> wrote:
> > I think the FP11 boards are not essential for the 11/70
> > They only add hardware FP support.
> Not essential for many uses, but I'm pretty sure UNIX is unhappy
> without them.  If you are going to run RSTS/E or RT-11, should be just
> fine either way.

Depends on the UNIX.  Ultrix works fine, and the latest patchlevel of
2.11BSD has floating point simulation that works fine.

(I'm running my 11/70 sans floating point hardware at the moment, I'd still
like to find a boardset one of these days, though.  Floating point
emulation is slow!)

> > However, I think that the cache boards are essential.
> > Not sure the 11/70 will work without them.
> Agreed.  I think those _are_ mandatory.

Yes, the cache is an integral part of the memory system on the 11/70.

- Josh

> Cheers,
> -ethan

More information about the cctech mailing list