7 Jun
2020
7 Jun
'20
8:30 a.m.
Love the title on this:
https://www.ebay.com/itm/184317705963
eBait auction: "16K Sense Inhibit Board .. VAX 6000, VAX-11/730".
Yeah, core on a VAX! And such a deal, a mere US$400!
Noel
7 Jun
7 Jun
9:31 a.m.
On 06/07/2020 10:30 AM, Noel Chiappa via cctalk wrote:
Love the title on this:
https://www.ebay.com/itm/184317705963
eBait auction: "16K Sense Inhibit Board .. VAX 6000, VAX-11/730".
Yeah, core on a VAX! And such a deal, a mere US$400!
1974 date codes. Not too
likely to be VAX related!
Jon
2:11 p.m.
prolly found it in a box of vax stuff lol
On Sun, Jun 7, 2020 at 11:31 AM Jon Elson via cctalk <cctalk at classiccmp.org>
wrote:
On 06/07/2020 10:30 AM, Noel Chiappa via cctalk
wrote:
Love the title on this:
https://www.ebay.com/itm/184317705963
eBait auction: "16K Sense Inhibit Board .. VAX 6000, VAX-11/730".
Yeah, core on a VAX! And such a deal, a mere US$400!
1974 date codes. Not too
likely to be VAX related!
Jon
2:55 p.m.
On 6/7/2020 2:11 PM, Adrian Stoness via cctalk wrote:
prolly found it in a box of vax stuff lol
On Sun, Jun 7, 2020 at 11:31 AM Jon Elson via cctalk <cctalk at classiccmp.org>
wrote:
> On 06/07/2020 10:30 AM, Noel Chiappa via cctalk wrote:
>> Love the title on this:
>>
>> https://www.ebay.com/itm/184317705963
>>
>> eBait auction: "16K Sense Inhibit Board .. VAX 6000, VAX-11/730".
>> Yeah, core on a VAX! And such a deal, a mere US$400!
> 1974 date codes. Not too likely to be VAX related!
>
> Jon
>
Large numbers of keyboards listed.? There are DEC keyboards listed and a
"Vintage VT320 monitor" for sale separately.
muttering dirty words.
5:11 p.m.
On 2020-Jun-07, at 8:30 AM, Noel Chiappa via cctalk wrote:
Love the title on this:
https://www.ebay.com/itm/184317705963
eBait auction: "16K Sense Inhibit Board .. VAX 6000, VAX-11/730".
Yeah, core on a VAX! And such a deal, a mere US$400!
To add to the weirdness, here are some actual core boards (the module companions to the
above board?),
https://www.ebay.com/itm/DEC-Digital-Core-Memory-H-217C-13258-H217C-1210711…
https://www.ebay.com/itm/DEC-Digital-Core-Memory-H217D-H2127D-6207/11138401…
Same "VAX 6000 / VAX-11/730", but from a different seller.
7:52 p.m.
On 06/07/2020 07:11 PM, Brent Hilpert via cctalk wrote:
On 2020-Jun-07, at 8:30 AM, Noel Chiappa via cctalk
wrote:
Hmmm, separate
sentence, I think they are saying they have
VAX 6000's and VAX 730's available,
call for freight quote. Wow, who would want a 730?
Jon
Love the title on this:
https://www.ebay.com/itm/184317705963
eBait auction: "16K Sense Inhibit Board .. VAX 6000, VAX-11/730".
Yeah, core on a VAX! And such a deal, a mere US$400!
To add to the weirdness, here
are some actual core boards (the module companions to the above board?),
https://www.ebay.com/itm/DEC-Digital-Core-Memory-H-217C-13258-H217C-1210711…
https://www.ebay.com/itm/DEC-Digital-Core-Memory-H217D-H2127D-6207/11138401…
Same "VAX 6000 / VAX-11/730", but from a different seller. 
8 Jun
8 Jun
3:03 a.m.
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of r.stricklin via
cctalk
Sent: 08 June 2020 07:36
To: General Discussion: On-Topic Posts <cctech at classiccmp.org>
Subject: Re: Someone's confused
On Jun 7, 2020, at 7:52 PM, Jon Elson via cctech wrote:
Well I would like one if I had the space. I might make space if one came up!
Wow, who would want a 730?
Somebody very, very determined.
ok
bear.
--
until further notice
5:46 a.m.
On 08/06/2020 13:02, emanuel stiebler via cctalk wrote:
Guys be nice! That's the slowest VAX, right?
In a small cabinet, I would take it, simply for that ;-)
In terms of speed I think the MicroVAX I might be even slower, although
whether you'd notice would be questionable!
In terms of size the MicroVAX I is considerably more convenient.
Antonio
--
Antonio Carlini
antonio at acarlini.com
8:55 a.m.
I have a MV1 board set here, I'd be willing to fire up VMS to see if
it's slower if someone wants to send me a TK50 boot tape but I'm
guessing it would be the slowest Vax on earth.
Reasons why:
1) MV1 has only 4mb of memory to the 730's 5mb.
2) I believe the 730 accesses memory in 32 bit chunks as opposed to the
MV1 having to access memory over the Q bus in 16 bit words. So you're
double bucking there. Don't remember if the MV1 has a cache.
3) An 11/730 has that R80 controller. The R80 is most probably faster
than the RQDX3+RD54, note that the RQDX3 is a slug of a controller
compared even to a MTI ESDI controller. Possibly due to the MFM interface.
4) The 11/730 could emulate pdp11 instructions, the MV1 could not. Come
to think of it I think the 730's floating point could do D,F,G,H while
the MV1 could only do D,F,G.
I'm not sure why they didn't do PMI memory on the MV1, possibly because
it's two boards already and they might already talk over CD
interconnect, limiting the memory to one card. But the result is a
really slow little VAX, probably slower than the 730.
C
On 6/8/2020 8:46 AM, Antonio Carlini via cctalk wrote:
On 08/06/2020 13:02, emanuel stiebler via cctalk
wrote:
Guys be nice! That's the slowest VAX, right?
In a small cabinet, I would take it, simply for that ;-)
In terms of speed I think the MicroVAX I might be even slower, although
whether you'd notice would be questionable!
In terms of size the MicroVAX I is considerably more convenient.
Antonio
9:50 a.m.
On 08/06/2020 16:55, Chris Zach via cctalk wrote:
I have a MV1 board set here, I'd be willing to
fire up VMS to see if
it's slower if someone wants to send me a TK50 boot tape but I'm
guessing it would be the slowest Vax on earth.
Reasons why:
1) MV1 has only 4mb of memory to the 730's 5mb.
2) I believe the 730 accesses memory in 32 bit chunks as opposed to
the MV1 having to access memory over the Q bus in 16 bit words. So
you're double bucking there. Don't remember if the MV1 has a cache.
3) An 11/730 has that R80 controller. The R80 is most probably faster
than the RQDX3+RD54, note that the RQDX3 is a slug of a controller
compared even to a MTI ESDI controller. Possibly due to the MFM
interface.
4) The 11/730 could emulate pdp11 instructions, the MV1 could not.
Come to think of it I think the 730's floating point could do D,F,G,H
while the MV1 could only do D,F,G.
I'm not sure why they didn't do PMI memory on the MV1, possibly
because it's two boards already and they might already talk over CD
interconnect, limiting the memory to one card. But the result is a
really slow little VAX, probably slower than the 730.
I think the MicroVAX I was (at least in part) built quickly to prove
that it could be done and was always intended to be superseded by the
MicroVAX II (which took longer and was more efficient).
I'm sure I've seen explanations on the net before, but I can't find them
now. Maybe I read it on the EASYNET? In which case, until someone is
willing to release their backups of some of DEC's internal NOTES
conferences, we'll possibly never know.
Antonio
--
Antonio Carlini
antonio at acarlini.com
10:13 a.m.
I believe your recollection is correct. I was working on a project and
looking at replacing a bunch of 11 boxes, and we had an NDA discussion
of what would be MVII. WE selected those to replace the aging 11
boxes, the configuration gave us more compute nodes, less power
consumption, and much less physical space needed to house the gear.
Worked great for a long time. Of course later, the uVII boxes were
consolidated into larger vax offerings, but combining the functions of
multiple uVII boses.
bb
On Mon, Jun 8, 2020 at 12:51 PM Antonio Carlini via cctalk
<cctalk at classiccmp.org> wrote:
On 08/06/2020 16:55, Chris Zach via cctalk wrote:
I have a MV1 board set here, I'd be willing
to fire up VMS to see if
it's slower if someone wants to send me a TK50 boot tape but I'm
guessing it would be the slowest Vax on earth.
Reasons why:
1) MV1 has only 4mb of memory to the 730's 5mb.
2) I believe the 730 accesses memory in 32 bit chunks as opposed to
the MV1 having to access memory over the Q bus in 16 bit words. So
you're double bucking there. Don't remember if the MV1 has a cache.
3) An 11/730 has that R80 controller. The R80 is most probably faster
than the RQDX3+RD54, note that the RQDX3 is a slug of a controller
compared even to a MTI ESDI controller. Possibly due to the MFM
interface.
4) The 11/730 could emulate pdp11 instructions, the MV1 could not.
Come to think of it I think the 730's floating point could do D,F,G,H
while the MV1 could only do D,F,G.
I'm not sure why they didn't do PMI memory on the MV1, possibly
because it's two boards already and they might already talk over CD
interconnect, limiting the memory to one card. But the result is a
really slow little VAX, probably slower than the 730.
I think the MicroVAX I was (at least in part) built quickly to prove
that it could be done and was always intended to be superseded by the
MicroVAX II (which took longer and was more efficient).
I'm sure I've seen explanations on the net before, but I can't find them
now. Maybe I read it on the EASYNET? In which case, until someone is
willing to release their backups of some of DEC's internal NOTES
conferences, we'll possibly never know.
Antonio
--
Antonio Carlini
antonio at acarlini.com
12:26 p.m.
On 2020-06-08 11:55, Chris Zach via cctalk wrote:
4) The 11/730 could emulate pdp11 instructions, the
MV1 could not. Come
to think of it I think the 730's floating point could do D,F,G,H while
the MV1 could only do D,F,G.
IIRC, there were two versions of the MV I board sets with different
floating points?
19 Jun
19 Jun
5:37 p.m.
Yes, there was D and F, and F and G versions. Everything else was
emulated slowly. Putt putt it was....
On 6/8/2020 3:26 PM, emanuel stiebler wrote:
On 2020-06-08 11:55, Chris Zach via cctalk wrote:
4) The 11/730 could emulate pdp11 instructions,
the MV1 could not. Come
to think of it I think the 730's floating point could do D,F,G,H while
the MV1 could only do D,F,G.
IIRC, there were two versions of the MV I board sets with different
floating points?
20 Jun
20 Jun
7:48 a.m.
On 2020-06-19 20:37, Chris Zach wrote:
Yes, there was D and F, and F and G versions.
Everything else was
emulated slowly. Putt putt it was....
Right! I have at least one of them. You know how one would see, which
one it is? Different board numbers?
On 6/8/2020 3:26 PM, emanuel stiebler wrote:
> On 2020-06-08 11:55, Chris Zach via cctalk wrote:
>
>> 4) The 11/730 could emulate pdp11 instructions, the MV1 could not. Come
>> to think of it I think the 730's floating point could do D,F,G,H while
>> the MV1 could only do D,F,G.
>
> IIRC, there were two versions of the MV I board sets with different
> floating points?
>
8 Jun
8 Jun
12:49 p.m.
On 6/8/2020 6:46 AM, Antonio Carlini via cctalk wrote:
On 08/06/2020 13:02, emanuel stiebler via cctalk
wrote:
But speed is relative. They changed computers where I was studing
electronics from a IBM-1130 to a VAX (something) in 1982.
I could use the IBM but the not VAX because they would have too
many users if that division had access to the VAX, and the
electonics section had PDP8 computers anyway.
So I suspect any VAX with one user would be faster than REAL
world machines in 1980's.
Ben.
PS:Virtual memory thrashing is what slows a computer down,
not say a 10,000 monkeys typing Shakespeare on ASR-33's.
Guys be nice! That's the slowest VAX, right?
In a small cabinet, I would take it, simply for that ;-)
In terms of speed I think the MicroVAX I might be even slower, although
whether you'd notice would be questionable!
In terms of size the MicroVAX I is considerably more convenient.
Antonio
1:54 p.m.
On 6/8/20 12:49 PM, ben via cctalk wrote:
But speed is relative. They changed computers where I
was studing
electronics from a IBM-1130 to a VAX (something) in 1982.
I could use the IBM but the not VAX because they would have too
many users if that division had access to the VAX, and the
electonics section had PDP8 computers anyway.
So I suspect any VAX with one user would be faster than REAL
world machines in 1980's.
Ben.
PS:Virtual memory thrashing is what slows a computer down,
not say a 10,000 monkeys typing Shakespeare on ASR-33's.
Well, one of the problems is the OS scheduling users without the ability
to manage resources.
There's nothing wrong with virtual memory, provided that it's managed
correctly. When the illusion of lots of memory causes the scheduler to
drastically over-commit resources, you get thrashing and nobody gets
anything done.
Although there are exceptions. I recall that it was possible, using
large page sizes on the CDC STAR-100 to execute an instruction that
could never get started. The STAR had 512KW (64 bits) of memory and a
large page size was 64KW. A typical vector instruction could require 6
addresses for source, destination and control vectors. Put the starting
address of any of these in last 8 words of a page and the hardware
faulted preemptively for next page. It was kind of funny to watch; the
P-counter for the user never budged, but the pager was sucking up time
like crazy. I think someone eventually devised a check in the pager for
this case, but I'm not certain.
--Chuck
3:40 p.m.
On 08/06/2020 21:54, Chuck Guzis via cctalk wrote:
Although there are exceptions. I recall that it was
possible, using
large page sizes on the CDC STAR-100 to execute an instruction that
could never get started. The STAR had 512KW (64 bits) of memory and a
large page size was 64KW. A typical vector instruction could require 6
addresses for source, destination and control vectors. Put the starting
address of any of these in last 8 words of a page and the hardware
faulted preemptively for next page. It was kind of funny to watch; the
P-counter for the user never budged, but the pager was sucking up time
like crazy. I think someone eventually devised a check in the pager for
this case, but I'm not certain.
There was a standard VAX quiz question which was something along the
lines of "what's the largest number of page faults can a single (valid)
instruction cause" and the answer was surprisingly large (in the region
of 50+ although I can no longer remember the details.
Antonio
--
Antonio Carlini
antonio at acarlini.com
5:24 p.m.
On Jun 8, 2020, at 6:40 PM, Antonio Carlini via cctalk
<cctalk at classiccmp.org> wrote:
On 08/06/2020 21:54, Chuck Guzis via cctalk wrote:
I would have thought a lot more than that, for string instructions with long operands.
Re the STAR thing, that reminds me of a bug I encountered a decade or so ago on a high end
MIPS architecture processor whose manufacturer shall remain nameless. It would prefetch
instructions, issuing memory reads to fill the cache if necessary. So far so good. But
if you hit a backward branch and then a prefetch for an address past that branch
completed, the CPU would consider that access wasted and throw away the data. It
wouldn't put it in the cache -- so the next time through the loop you'd get that
memory reference again, and again, every iteration.
This actually broke things in a cache flush operation because that required the execution
of some intensely hairy code that was required to run without any extra cache misses.
This bug meant that you'd always get a cache miss at the end of the loop. The fix
required some additional very hairy code to hop ahead through address space to get those
cache lines actually into the cache...
paul
Although there are exceptions. I recall that it
was possible, using
large page sizes on the CDC STAR-100 to execute an instruction that
could never get started. The STAR had 512KW (64 bits) of memory and a
large page size was 64KW. A typical vector instruction could require 6
addresses for source, destination and control vectors. Put the starting
address of any of these in last 8 words of a page and the hardware
faulted preemptively for next page. It was kind of funny to watch; the
P-counter for the user never budged, but the pager was sucking up time
like crazy. I think someone eventually devised a check in the pager for
this case, but I'm not certain.
There was a standard VAX quiz question which was something along the lines of
"what's the largest number of page faults can a single (valid) instruction
cause" and the answer was surprisingly large (in the region of 50+ although I can no
longer remember the details.
3:37 p.m.
On 08/06/2020 20:49, ben via cctalk wrote:
But
speed is relative. They changed computers where I was studing
electronics from a IBM-1130 to a VAX (something) in 1982.
I could use the IBM but the not VAX because they would have too
many users if that division had access to the VAX, and the
electonics section had PDP8 computers anyway.
So I suspect any VAX with one user would be faster than REAL
world machines in 1980's.
All my VAXes are now single user and quite likely to remain that way :-)
Maybe if I ever get a house with a very large basement or very large
outbuildings that can act as a computer room, then that might change.
But for now, my VAXstation 4000 M9x is faster than almost all of my
other VAXes (not counting SIMH).
Antonio
--
Antonio Carlini
antonio at acarlini.com
5:50 a.m.
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of emanuel stiebler
via cctalk
Sent: 08 June 2020 13:03
To: r.stricklin <bear at typewritten.org>; General Discussion: On-Topic and Off-
Topic Posts <cctalk at classiccmp.org>; General Discussion: On-Topic Posts
<cctech at classiccmp.org>
Subject: Re: Someone's confused
On 2020-06-08 02:35, r.stricklin via cctalk wrote:
Yes, it is pretty slow. I used to use one in the mid 80's and I rescued the boards
from it when it was about to be scrapped. I gave a couple of boards to someone who I
don't think did anything with them in the end ?
On Jun 7, 2020, at 7:52 PM, Jon Elson via cctech wrote:
Guys be nice! That's the slowest VAX, right?
In a small cabinet, I would take it, simply for that ;-) Wow, who would want a 730?
Somebody very,
very determined. 
7 Jun
7 Jun
11:55 p.m.
On Mon, Jun 8, 2020 at 3:53 AM Jon Elson via cctalk
<cctalk at classiccmp.org> wrote:
Wow, who would want a 730?
I would. Well, actually I have one so I don't need another but you get
the point.
There are only 2 families of VAXen that I would want to own/run. The
11/730 and the 11/780. The reason is that those are the only ones I
could repair. And I don't have the space for a 780 or similar.
The fact that the 730 is entirely soft microcode (how I wish there was
more documentation on that) is a bonus
-tony
8 Jun
8 Jun
10:26 a.m.
On Sun, Jun 7, 2020 at 10:53 PM Jon Elson via cctalk
<cctalk at classiccmp.org> wrote:
Hmmm, separate sentence, I think they are saying they
have
VAX 6000's and VAX 730's available,
call for freight quote. Wow, who would want a 730?
I would, but I already have one, so like Tony, I don't need *another* one.
-ethan
1429
days inactive
1442
days old
23 comments
16 participants
participants (16)
-
a.carlini＠ntlworld.com -
ard.p850ug1＠gmail.com -
bear＠typewritten.org -
bfranchuk＠jetnet.ab.ca -
bhilpert＠shaw.ca -
bobsmithofd＠gmail.com -
cclist＠sydex.com -
cz＠alembic.crystel.com -
elson＠pico-systems.com -
emu＠e-bbes.com -
ethan.dicks＠gmail.com -
jnc＠mercury.lcs.mit.edu -
jwsmail＠jwsss.com -
paulkoning＠comcast.net -
robert.jarratt＠ntlworld.com -
tdk.knight＠gmail.com