RT-11 Emulation under Ultrix?

[dan at rna.UUCP]

In article <567 at tekgen.UUCP> dickj at tekgen.UUCP (David White) writes:
>I have a team doing RT-11 development work under TSX on an 11/73
>machine that I would like to move onto a MVAX II under Ultrix.  Is
>anyone aware of any cross assemblers and C compilers that would run
>under Ultrix or BSD4.2,3 on a MVAX II that would produce modules that
>could be loaded into an 11/73 machine running Rt-11 for execution?  The
>ability to write disks in RT-11 format would also be useful.  Another
>possibility would be a RT-11 emulator that would run under Ultrix
>similiar to DEC's RTEM which runs under VMS.  Any input would be
>greatly appreciated since I don't want to bring up a machine to run
>that "other" operating system supplied by DEC.  Thanks in advance.

	The problem with most available cross-compilers for RT-11 is that
they use MACRO-11 as the output language.
	The problem with most RT-11 emulators on the VAX is that they use
the PDP-11 emulation mode which is not available on the MVAX II (but may be
on the MVAX III). HCR has/had a RT-11 emulator, but it wouldn't work on a
MVAX II.
	I suppose what I'd do is contact Whitesmith's, if they're still
around, and ask them. Or port PCC from the PDP-11. But then you'll need to
re-write AS and build your own linker. There was a DEC to UNIX object file
format conversion program back in the V6 days. It might help.
	Another wild idea is to run a PDP-11 co-processor on the MVAX II
bus, either a KXT-11CA or MDB's 11/73 co-processor. The MVAX II could act
as the file server for RT-11 on the co-processor. KXT-11CA's are available
on the surplus market for maybe $600.

	If you're willing to run UNIX or ULTRIX on your 11/73, then I'd
go with either HCR's RT-11 emulator or Whitesmith's C compiler. I have ported
and used both methods for developing RT-11 software under UNIX.

	As far as programs that can read/write RT-11 disks, the only one I
know of that works most of the time is RTPIP. I can get you a copy if you want.

					Cheers,
					Dan Ts'o
					Dept. Neurobiology
					Rockefeller Univ.
					1230 York Ave.
					NY, NY 10021
					212-570-7671
					...cmcl2!rna!dan
					rna!dan at cmcl2.arpa