Running RT11 on an 11/750 was only done by a software emulator RTEM that
made a VAX emulate an 11/40 with EIS and FIS.

The 86xx had a T11 front end that ran RT off an RL.
The 11/78x had an 11/03 front end that could boot RT11 RX01's.


will kranz wrote:
> I have a Vax-750 that I periodically attempt to boot, something like
> once every 4 years, and its about time. I know this is a PDP newsgroup
> but there has been a fair amount of Vax stuff recently and this is
> actually sort of on topic.
> Its my understanding that the Vax-750 had some sort of compatibility
> mode for RT11 (or is it generic 16 bit addressing)? Anyone know how to
> access and or control this? My diagnoistics tapes and consol tapes
> seem to be in RT11 format, not files11, although the home block
> format string is "DECVMSEXCHNG". If I could run it as a PDP11
> off the functional RL02 I might get further figuring out why the
> RA80 doesn't work.
> A bit further from PDP11s but of interest regarding this, what are
> the following from consol tape?
> BOOT58.EXE 02-20-85 23 blocks 14 start block
> CI780 .BIN 02-20-85 36 blocks 37 start block
> VMB .EXE 02-20-85 40 blocks 149 start block
> If this is well covered somewhere a link would be great.
> It seems to need a fair amount of this data from the
> TU58 consol tape before it will attempt to do anything. The
> recent comments about loading microcode patches was interesting.
> Presumably thats what CI780.bin is but why 780???
> From other reading, I believe it ultimately loads VMB.exe but don't
> know what this really is. Is this specific to early Vaxen
> like the 750? Is the equivalent in ROM on the microvax?
> Guess the other possibility is that the default state is a pdp11
> with a Unibus, and it only becomes a Vax via VMB.exe?
> Hints appreciated, Will
> At 09:54 AM 05/05/05 -0400, Bill Pechter wrote (in part):
> Original Thread Re: Does anyone here have an 11/60?
>>The 8650 was a beautiful machine...
>>'Course running full blown RT11 on the front end was nice... Running
>>adventure from an RL pack during PM was kind of fun.