9 Feb
2016
9 Feb
'16
8:27 a.m.
From: Jacob Ritorto
Can I tear apart my little BA23 .. and put the
Micro/PDP-11 backplane
.. into the spot that my 11/03 backplane currently occupies and run it
via the (working) stock 11/03 power supply?
...
Specifically, would I have to butcher power and clock lines to do this,
or is it all plug compatible?
I'm not absolutely sure exactly what you have that's holding the '11/03
backplane'; if it's a standard BA11-M enclosure, the answer, sadly, is
'no'.
The BA-23 uses the H9278-A backplane and H7864 power supply; the BA11-M uses
the H9270-A and H780 backplane. The power connections between the first two
are completely different from the latter pair; the first uses a long,
single-width Molex-type connector, the latter uses bare wire ends to a
terminal block on the backplane.
Also, the H9270-A is a four-slot backplane, and the H9278-A (an eight-slot)
almost certainly will not physically fit into the space for the former.
If your '11/03 backplane' is a different kind of backplane, in some other kind
of box (e.g. BA11-N or BA11-S), the answer, sadly, is still 'no', because they
both also use terminal blocks for power. (Although if you have a BA11-S, you'd
already be set, those are Q22 native.)
Really, it's not that hard to upgrade an H9270-A (or the H9273-A in a BA11-N)
to Q22 (I have done several of the latter); the transplant you speak of (were
it possible) is on the same order of magnitude of work.
Noel
PS: In dragging my BA23 out to look at it, it dawned on me that I will
probably never, ever use it - I now have several BA11-N/S boxes, and prefer
them. (I don't need to run the later disks that need the BA23.) So if someone
is interested in the either the BA23, or the spare H7864 I have for it, please
let me know. I'll let either go for my original cost plus shipping.
9 Feb
9 Feb
10:36 a.m.
On Tue, Feb 9, 2016 at 11:27 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:
I'm not absolutely sure exactly what you have that's holding the '11/03
backplane'; if it's a standard BA11-M enclosure, the answer, sadly, is
'no'.
[...]
If your '11/03 backplane' is a different kind of backplane, in some other
kind
of box (e.g. BA11-N or BA11-S), the answer, sadly, is still 'no', because
they
both also use terminal blocks for power. (Although if you have a BA11-S,
you'd
already be set, those are Q22 native.)
OK, now that I know what I'm looking for, my target options here are:
Chassis:
BA11-N and "OBA11-R" (an expansion box)
Backplanes currently in these chassis are:
H9273 and H9273-A
Power supplies are all H786.
Really, it's not that hard to upgrade an H9270-A
(or the H9273-A in a
BA11-N)
to Q22 (I have done several of the latter); the transplant you speak of
(were
it possible) is on the same order of magnitude of work.
Noel
So, since grafting in the Micro backplane would involve butcher work, I'm
now wholeheartedly convinced that I should be moving to your setup with the
BA11-N/S boxes, Noel. And I'm sold on the Q-22 backplane conversion
(despite failing the first time I tried it years ago). Going to study what
prints I have, review previous advice and go for it.
Thank you for all the tips and hand-holding!
--jake
6:56 p.m.
Jake,
On Tue, Feb 9, 2016 at 11:27 AM, Noel Chiappa <jnc
at mercury.lcs.mit.edu>
....
> Really, it's not that hard to upgrade an
H9270-A (or the H9273-A in a
> BA11-N)
> to Q22 (I have done several of the latter); the transplant you speak of
> (were
> it possible) is on the same order of magnitude of work.
>
> Noel
On Tue, Feb 09, 2016 at 01:36:24PM -0500, Jacob Ritorto wrote:
So, since grafting in the Micro backplane would
involve butcher work, I'm
now wholeheartedly convinced that I should be moving to your setup with the
BA11-N/S boxes, Noel. And I'm sold on the Q-22 backplane conversion
(despite failing the first time I tried it years ago). Going to study what
prints I have, review previous advice and go for it.
Thank you for all the tips and hand-holding!
I just did this conversion to an oddball dual-wide backplane, and
it was extremely was easy. I used a bag of 50 pre-cut wire-wrap
jumpers which were a few dollars from Jameco or Digikey.
This page (which even mentions Noel!) has clear information and
pictures identifying the four pins involved:
http://web.frainresearch.org:8080/projects/pdp-11/conv22.php
Mark
--
Mark G. Thomas (Mark at Misty.com), KC3DRE
10:28 p.m.
Yisssss. ?I struggled for hours with inadequate eyesight, tools and
materials, but I think I got this mod done!
My KDJ11-B is plugged into what was a stock H9273 (bc1, bd1, be1, bf1
chained straight down the backplane using four wires to be a H9276) and it
runs! I've only plugged in one other board, the memory, and it shows up
(4088KB as opposed to 248 KB before the Q22 mod) and seems to work for the
locations I've fiddled with in ODT, but the machine's stuck in self-test at
error 47, Memory CSR error.
It was stopping with this same error when I ran it as a "before" test in
the 18-bit backplane, so I'm guessing it's not just my mod causing the
error..
What I assume is the parity light on the third party "Clearpoint QRAM-2
SPB-1 88B" lights during self test. I've found no documentation for this
sucker as yet..
So unless my luck (and soldering) are terrible, I guess the years of
harsh storage may have broken something in the memory because it was fine
in 1999 before the power supply on the Micro failed. Heck, maybe that
event burned something on the memory board, too. I'll have to find my rl02
controller and build the system up some more so I can run xxdp and find out
what exactly died. Maybe it's just a bad socketed RAM.
Tip in case someone didn't know: You can break out of the never ending
self-test sequence by pressing crtl-O 4 when confronted with the 1,2,3 menu
and move on to other parts of the ROM (I did this so I could temporarily
disable the tests and get on with booting xxdp).
Thanks again to everybody for the encouragement! I freaking love these
machines and even this limited success feels fantastic. Stoked. You guys
are the best.
--jake
11:48 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Noel
Chiappa
Sent: 09 February 2016 16:27
To: cctalk at classiccmp.org
Cc: jnc at mercury.lcs.mit.edu
Subject: Re: 11/73 into 11/03 chassis?
backplane
From: Jacob Ritorto
> Can I tear apart my little BA23 .. and put the Micro/PDP-11 > .. into the spot that my 11/03 backplane
currently occupies and run
it
> via the (working) stock 11/03 power supply?
> ...
> Specifically, would I have to butcher power and clock lines to do
this,
or is it all
plug compatible?
I'm not absolutely sure exactly what you have that's holding the '11/03
backplane'; if it's a standard BA11-M enclosure, the answer, sadly, is
The BA-23 uses the H9278-A backplane and H7864 power supply; the BA11-M
uses the H9270-A and H780 backplane. The power connections between the
first two are completely different from the latter pair; the first uses a
long,
single-width Molex-type connector, the latter uses
bare wire ends to a
terminal block on the backplane.
Also, the H9270-A is a four-slot backplane, and the H9278-A (an
eight-slot)
almost certainly will not physically fit into the
space for the former.
If your '11/03 backplane' is a different kind of backplane, in some other
kind
of box (e.g. BA11-N or BA11-S), the answer, sadly, is
still 'no', because
they
both also use terminal blocks for power. (Although if
you have a BA11-S,
you'd already be set, those are Q22 native.)
Really, it's not that hard to upgrade an H9270-A (or the H9273-A in a
BA11-N)
to Q22 (I have done several of the latter); the
transplant you speak of
(were
it possible) is on the same order of magnitude of
work.
Noel
PS: In dragging my BA23 out to look at it, it dawned on me that I will
probably
never, ever use it - I now have several BA11-N/S
boxes, and prefer them.
(I
don't need to run the later disks that need the
BA23.) So if someone is
interested in the either the BA23, or the spare H7864 I have for it,
please let
me know. I'll let either go for my original cost
plus shipping.
Is this in the USA?
Regards
Rob
3238
days inactive
3239
days old
4 comments
4 participants
participants (4)
-
jacob.ritorto＠gmail.com -
jnc＠mercury.lcs.mit.edu -
Mark＠Misty.com -
robert.jarratt＠ntlworld.com