3 Feb
2017
3 Feb
'17
9 a.m.
From: Paul Koning
Another OS that would run on your machine (as well as
an 11/20) would
be RSTS-11 (V4, or I suppose V3 if you can find that)
I'd love to have an old RSTS-11, is there any variant around?
didn't use the MMU
Huh? He's got an MMU (I think): it's the EIS he's currently struggling with.
Noel
3 Feb
3 Feb
11:31 a.m.
On Feb 3, 2017, at 12:00 PM, Noel Chiappa <jnc at
mercury.lcs.mit.edu> wrote:
Yes, on bitsavers. But John's comment reminds me that RSTS-11 V4A doesn't support
RL02. (Only RF11, RK11, RP11.) V4B may be different, I don't know.
From: Paul Koning
Another OS that would run on your machine (as
well as an 11/20) would
be RSTS-11 (V4, or I suppose V3 if you can find that)
I'd love to have an old RSTS-11, is there any variant around? didn't use
the MMU
Huh? He's got an MMU (I think): it's the EIS he's currently struggling with.
12:25 p.m.
On Fri, Feb 3, 2017 at 2:31 PM, Paul Koning <paulkoning at comcast.net> wrote:
Yes, on bitsavers. But John's comment reminds me that RSTS-11 V4A doesn't
support RL02. (Only RF11, RK11, RP11.) V4B may be different, I don't know.
with.
True. I meant to point out the main difference between RSTS-11 and
RSTS/E. The other difference is that it doesn't require EIS. Both follow
from the fact it was designed for the 11/20.
paul
So you're saying for a system with a MMU but no working EIS (removed for
now) and 64KW RAM (half populated M7891) you're suggesting which OS? I
still have to research the best options, RSX-11M?
I was able to get the extended three cables so I can put the M7238 EIS card
on a riser so I can probe for faults, and maybe if I am lucky boot XXDP+.
With the EIN installed I can't boot RT-11
On Feb 3, 2017, at 12:00 PM, Noel Chiappa <jnc
at mercury.lcs.mit.edu>
wrote:
From: Paul Koning
Another OS that would run on your machine (as
well as an 11/20) would
be RSTS-11 (V4, or I suppose V3 if you can find that)
I'd love to have an old RSTS-11, is there any variant around?
didn't use the MMU
Huh? He's got an MMU (I think): it's the EIS he's currently struggling
12:31 p.m.
On Feb 3, 2017, at 3:25 PM, william degnan
<billdegnan at gmail.com> wrote:
On Fri, Feb 3, 2017 at 2:31 PM, Paul Koning <paulkoning at comcast.net> wrote:
Yes, on bitsavers. But John's comment reminds me that RSTS-11 V4A doesn't
support RL02. (Only RF11, RK11, RP11.) V4B may be different, I don't know.
with.
True. I meant to point out the main difference between RSTS-11 and
RSTS/E. The other difference is that it doesn't require EIS. Both follow
from the fact it was designed for the 11/20.
paul
So you're saying for a system with a MMU but no working EIS (removed for
now) and 64KW RAM (half populated M7891) you're suggesting which OS? I
still have to research the best options, RSX-11M?
I'm not sure there is one. DEC OS designers typically would assume that they are
dealing with non-broken systems. Systems with MMU all have EIS, so an OS that requires an
MMU would typically take advantage of EIS instructions. That's the case in RSTS/E,
for example.
OSs designed for non-MMU systems would also typically assume no EIS, because they were
intended for the entire PDP-11 family including 11/20 and the like.
In other words, if you don't have an EIS that works, you're likely to be limited
to no-MMU systems because those are likely to be the only ones whose authors avoided EIS
instructions.
There may be some mixed cases, an OS where the same basic system can be built for no-MMU
as well as MMU configs. If so, there might be a way to build an MMU=yes, EIS=no config.
Or it may come with EIS=no by default because some of its configs have to handle that and
it's easier to do it consistenly. Possibly RSX is such an OS; I don't know.
paul
On Feb 3, 2017, at 12:00 PM, Noel Chiappa <jnc
at mercury.lcs.mit.edu>
wrote:
From: Paul Koning
Another OS that would run on your machine (as
well as an 11/20) would
be RSTS-11 (V4, or I suppose V3 if you can find that)
I'd love to have an old RSTS-11, is there any variant around?
didn't use the MMU
Huh? He's got an MMU (I think): it's the EIS he's currently struggling
1:03 p.m.
1:08 p.m.
Will wrote...
------
OK. Hopefully I can repair my EIS board then. Otherwise it's RT-11.
------
Don't forget the RT-11 + TSX+ option, very nice timesharing system.
http://tsxplus.classiccmp.org
1:07 p.m.
On Fri, Feb 3, 2017 at 12:31 PM, Paul Koning <paulkoning at comcast.net> wrote:
I'm not sure there is one. DEC OS designers typically would assume that
they are dealing with non-broken systems. Systems with MMU all have EIS...
Is this actually true? I've been working on getting my PDP-11/40 running
recently, and I don't recall anything in the documentation indicating that
an EIS was required if you had an MMU installed. (On the other hand, the
MMU docs indicate that the Stack Limit Register must be installed if an MMU
is present, though I haven't looked into why this is the case). For the
record, my system currently has the MMU, but lacks an EIS (still trying to
track one down). It may be that DEC never shipped an MMU without an EIS in
an 11/40...
- Josh
1:17 p.m.
On Feb 3, 2017, at 4:07 PM, Josh Dersch <derschjo
at gmail.com> wrote:
On Fri, Feb 3, 2017 at 12:31 PM, Paul Koning <paulkoning at comcast.net> wrote:
What I meant is that the 11/40 has EIS standard, according to the PDP11 architecture
handbook. So an OS that depends on MMU would be designed for 11/40, 11/45, etc. all of
which have EIS. And since EIS instructions are quite helpful they will be used. Not
necessarily MUL, in a kernel, but definitely SOB.
paul
I'm not sure there is one. DEC OS designers typically would assume that
they are dealing with non-broken systems. Systems with MMU all have EIS...
Is this actually true? I've been working on getting my PDP-11/40 running
recently, and I don't recall anything in the documentation indicating that
an EIS was required if you had an MMU installed.
1:28 p.m.
On Fri, Feb 3, 2017 at 1:17 PM, Paul Koning <paulkoning at comcast.net> wrote:
Is this actually true? I've been working on getting my PDP-11/40 running
recently, and I don't recall anything in the documentation indicating that
EIS was an option on the 11/40, it was not standard.
https://pdos.csail.mit.edu/6.828/2005/readings/pdp11-40.pdf, section 2.4.
- Josh
On Feb 3, 2017, at 4:07 PM, Josh Dersch
<derschjo at gmail.com> wrote:
On Fri, Feb 3, 2017 at 12:31 PM, Paul Koning <paulkoning at comcast.net>
wrote:
>
>
>
> I'm not sure there is one. DEC OS designers typically would assume that
> they are dealing with non-broken systems. Systems with MMU all have
EIS...
an EIS was required if you had an MMU installed.
What I meant is that the 11/40 has EIS standard, according to the PDP11
architecture handbook. So an OS that depends on MMU would be designed for
11/40, 11/45, etc. all of which have EIS. And since EIS instructions are
quite helpful they will be used. Not necessarily MUL, in a kernel, but
definitely SOB.
paul
1:35 p.m.
On Feb 3, 2017, at 4:28 PM, Josh Dersch <derschjo
at gmail.com> wrote:
On Fri, Feb 3, 2017 at 1:17 PM, Paul Koning <paulkoning at comcast.net> wrote:
I saw that stated earlier, too, but DEC's PDP11 architecture handbook doesn't
appear to confirm that. Either that or the model differences table is sloppy.
paul
...
What I meant is that the 11/40 has EIS standard, according to the PDP11
architecture handbook. So an OS that depends on MMU would be designed for
11/40, 11/45, etc. all of which have EIS. And since EIS instructions are
quite helpful they will be used. Not necessarily MUL, in a kernel, but
definitely SOB.
EIS was an option on the 11/40, it was not standard.
https://pdos.csail.mit.edu/6.828/2005/readings/pdp11-40.pdf, section 2.4. 
2:38 p.m.
On Fri, Feb 3, 2017 at 2:35 PM, Paul Koning <paulkoning at comcast.net> wrote:
I saw that stated earlier, too, but DEC's PDP11
architecture handbook
doesn't appear to confirm that. Either that or the model differences table
is sloppy.
The model differences table is definitely sloppy. There are discrepancies
between versions of that table in the various processor handbooks, also.
2659
days inactive
2660
days old
12 comments
7 participants
participants (7)
-
billdegnan＠gmail.com -
derschjo＠gmail.com -
ethan.dicks＠gmail.com -
jnc＠mercury.lcs.mit.edu -
jwest＠classiccmp.org -
paulkoning＠comcast.net -
spacewar＠gmail.com