7 Mar
2020
7 Mar
'20
2:11 p.m.
On 2020-03-07 02:12, Robert Armstrong wrote:
Unless I remember wrong, initially AME wasn't that much of a product,
but a part of VMS itself. Early versions of VMS was pretty much mostly
RSX userland, with only a few VMS specific components. Over time this
changed, obviously.
Didn't
early Vaxen (11/780) also execute PDP-11 code?
? Yes, you are correct that the hardware could do it but to actually
run PDP-11 programs you needed a layered software product for VMS called
the RSXAME (?Application Migration Executive?).? The AME came with
MACRO11, task builder, and a bunch of other stuff. ??I don?t have it, though, and I haven?t seen a copy
since the early
1980s.? I?m not even sure it would work on a MicroVAX, either.? Only the
VAX-7xx models and (I think) the 8600 actually had compatibility mode;
it got dropped from the architecture pretty fast after that.? I seem to
remember that DEC added a software emulation feature for later VAXes
that didn?t have compatibility mode, but I don?t remember the details.
As VAXen stopped including PDP-11 compatibility, AME became more of an
actual product which was separate. This then also included emulating the
whole PDP-11 instruction set on machines that didn't the compatibility
mode. So by this time, installing AME was possible on any VAX.
And yes, only the VAX-11 machines had PDP-11 compatibility mode in
hardware (and I still kindof think of the 8600 as the VAX-11/790, which
was the original designation for it). No machines after the 86x0 have
the compatibility mode in hardware. And no micro-VAX ever had it.
AME was definitely a product still in the 90s. I think it got retired
along with the VAX itself. AME is (obviously) not available on Alpha or
anything newer.
One thing I'm sortof curious about is if a VAX-11 could run an RSX
program even without AME. Actually, maybe I should just try, since I do
have the way of testing that... But it might be that even the system
calls were diked out of VMS and placed in AME at some point, along with
the handling of switching in and out of PDP-11 mode.
? In any case I don?t really need all that ? I just
want to assemble
some stand alone PDP-11 programs that I can then download to a real -11.
I think using a PDP-11 is easier than getting AME.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol