Re: New Vax - future directions :-)

[Johnny Billquist <bqt%update.uu.se@localhost>]

On 2021-07-07 17:56, Mouse wrote:
> > Did anything except VMS ever make any use of [PDP-11 mode]?  (NetBSD
> > for sure not, but I don't think Ultrix or ELN cared either.)
>
> ISTR something about keeping "an old, sourceless, Zork binary" running.
> That would have been 4.3BSD, I'm guessing?  Or perhaps my wetware
> memory is bitrotting?

The Zork binary for 2.11BSD is a really odd hack. It sortof implements 
part of the RT-11 environment, and uses sortof the RT-11 binary, since 
the BSD F77 compiler wasn't really capable of generating good enough 
code to make it fit.

To quote selected bit from READ_ME in 2.11BSD:

o.s             Assembler driver to make dungeon run under UNIX.
                Loads overlays, save/restore games, etc.  This must
                be relocated to 0146000 and stuck on the end of the
                dungeon binary file "d". (We don't have sources)

So your memory is pretty good, but it was really the proper PDP-11 stuff.

> I could add PDP-11 mode to my KA630 simulator and then add support for
> it to NetBSD, so that if/when an FPGA version exists there'll be a
> little more software ready for it.

You just need some software then.
And no, ZORK won't cut it. It uses separate I/D space. :-)

  Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol