17 Apr
2019
17 Apr
'19
12:44 p.m.
?Hi friends. I am putting together a PDP-11 set up. i have a few CPUs available to me, a
11/23+, an 11/73 and I also have available to me an 11/83, M8190-AE .
I would like to try to run as many different OS's as may interest me, including some
unixes as possible (bsd...etc). My question is, are there any OSes that need the floating
point option?
Another question is, would I see any improvement in performance with the FPU compared to
without it? Or does the application running need to be something like fortran to see any
perceivable difference?
Thanks
17 Apr
17 Apr
1:36 p.m.
On Wed, Apr 17, 2019 at 2:48 PM W2HX via cctalk <cctalk at classiccmp.org> wrote:
?Hi friends. I am putting together a PDP-11 set up. i
have a few CPUs available to me, a 11/23+, an 11/73 and I also have available to me an
11/83, M8190-AE .
I would like to try to run as many different OS's as may interest me, including some
unixes as possible (bsd...etc). My question is, are there any OSes that need the floating
point option?
I know old UNIX (v2) needs a KE11-A or KE11-B (a Unibus peripheral
integer math option), which really wasn't something people
bought/installed in an 11/34 or later. v5, v6, and v7 UNIX shouldn't
require any sort of math hardware.
Simple OSes like RT-11 do not require it and the The usual DEC
timesharing OSes (RSX-11, RSTS/E...) won't require it,, though you may
encounter a FORTRAN application that was compiled to require it.
-ethan
2:19 p.m.
On Apr 17, 2019, at 4:36 PM, Ethan Dicks via cctalk
<cctalk at classiccmp.org> wrote:
On Wed, Apr 17, 2019 at 2:48 PM W2HX via cctalk <cctalk at classiccmp.org> wrote:
I think that was typically called "EAE" (extended arithmetic element), a Unibus
peripheral that implemented integer mul/div and maybe a few other odds and ends. RSTS V4
had optional support for that. It only applies to 11/20 and 11/05 since all the other
machines have the relevant instructions built into the CPU. (Later versions of RSTS
required that.)
?Hi friends. I am putting together a PDP-11 set
up. i have a few CPUs available to me, a 11/23+, an 11/73 and I also have available to me
an 11/83, M8190-AE .
I would like to try to run as many different OS's as may interest me, including some
unixes as possible (bsd...etc). My question is, are there any OSes that need the floating
point option?
I know old UNIX (v2) needs a KE11-A or KE11-B (a Unibus peripheral
integer math option), which really wasn't something people
bought/installed in an 11/34 or later. v5, v6, and v7 UNIX shouldn't
require any sort of math hardware. Simple OSes like RT-11 do not require it and the The
usual DEC
timesharing OSes (RSX-11, RSTS/E...) won't require it,, though you may
encounter a FORTRAN application that was compiled to require it.
In the case of RSTS, you could build your BASIC-PLUS either for FPU or not. If you tried
to run the FPU version it would of course fail badly without that option, but you could
then swap in the other one and applications would run fine.
One curious detail: in the very early days DEC had a floating point software library that
uses three words per value: 2 word mantissa, 1 word exponent. The source code for that
popped up recently in a collection of TOPS-10 DECtape images, I remember writing an email
to the list identifying it along with various other items. RSTS V3 (and I assume before)
used that float library. Then in V4 they switched to the new standard, your choice of 2
or 4 word float which matches the FPU formats. Apparently they pulled that change without
any means to convert existing binary data files; probably there weren't enough to
worry.
paul
9:44 p.m.
On Wed, Apr 17, 2019 at 2:58 PM Paul Koning via cctalk <
cctalk at classiccmp.org> wrote:
The EAE was also an option on the 11/40.
At any rate, on the 11/73 and 83 CPU, the microcode emulates the floating
point instructions if an actual FPA isn't fitted, so everything should just
work (just a bit slower).
- Josh
On Apr 17, 2019, at 4:36 PM, Ethan Dicks via
cctalk <
cctalk at classiccmp.org> wrote:
On Wed, Apr 17, 2019 at 2:48 PM W2HX via cctalk <cctalk at classiccmp.org>
wrote:
> ?Hi friends. I am putting together a PDP-11
set up. i have a few CPUs
available to me, a 11/23+, an 11/73 and I also have
available to me an
11/83, M8190-AE .
>
> I would like to try to run as many different OS's as may interest me,
including some unixes as possible (bsd...etc). My question is, are there
any OSes that need the floating point option?
I know old UNIX (v2) needs a KE11-A or KE11-B (a Unibus peripheral
integer math option), which really wasn't something people
bought/installed in an 11/34 or later. v5, v6, and v7 UNIX shouldn't
require any sort of math hardware.
I think that was typically called "EAE" (extended arithmetic element), a
Unibus peripheral that implemented integer mul/div and maybe a few other
odds and ends. RSTS V4 had optional support for that. It only applies to
11/20 and 11/05 since all the other machines have the relevant instructions
built into the CPU. (Later versions of RSTS required that.)
10:24 p.m.
Are you referring to the M7238 EIS on the 11/40?
On Wed, Apr 17, 2019 at 11:45 PM Josh Dersch via cctalk <
cctalk at classiccmp.org> wrote:
On Wed, Apr 17, 2019 at 2:58 PM Paul Koning via cctalk
<
cctalk at classiccmp.org> wrote:
to
On Apr 17, 2019, at 4:36 PM, Ethan Dicks via
cctalk <
cctalk at classiccmp.org> wrote:
On Wed, Apr 17, 2019 at 2:48 PM W2HX via cctalk <cctalk at classiccmp.org
wrote:
> ?Hi friends. I am putting together a PDP-11
set up. i have a few CPUs
available to me, a 11/23+, an 11/73 and I also have
available to me an
11/83, M8190-AE .
>
> I would like to try to run as many different OS's as may interest me,
including some unixes as possible (bsd...etc). My question is, are there
any OSes that need the floating point option?
I know old UNIX (v2) needs a KE11-A or KE11-B (a Unibus peripheral
integer math option), which really wasn't something people
bought/installed in an 11/34 or later. v5, v6, and v7 UNIX shouldn't
require any sort of math hardware.
I think that was typically called "EAE" (extended arithmetic element), a
Unibus peripheral that implemented integer mul/div and maybe a few other
odds and ends. RSTS V4 had optional support for that. It only applies 11/20 and 11/05 since all the other machines have
the relevant
instructions
built into the CPU. (Later versions of RSTS
required that.)
The EAE was also an option on the 11/40.
At any rate, on the 11/73 and 83 CPU, the microcode emulates the floating
point instructions if an actual FPA isn't fitted, so everything should just
work (just a bit slower).
- Josh
8:34 p.m.
W2HX via cctalk wrote:
?Hi friends. I am putting together a PDP-11 set up. i
have a few CPUs available to me, a 11/23+, an 11/73 and I also have available to me an
11/83, M8190-AE .
I would like to try to run as many different OS's as may interest me, including some
unixes as possible (bsd...etc). My question is, are there any OSes that need the floating
point option?
Another question is, would I see any improvement in performance with the FPU compared to
without it? Or does the application running need to be something like fortran to see any
perceivable difference?
Thanks
2.11BSD needs it. There is an peace of emulator software in it, but as
far as I know it never really worked.
Regards,
Holm
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participants (6)
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derschjo＠gmail.com -
ethan.dicks＠gmail.com -
holm＠freibergnet.de -
paulkoning＠comcast.net -
useddec＠gmail.com -
w2hx＠w2hx.com