> From: Mister PDP
> Wow, I wasn't aware that the ODT console needed memory to run.
It was news to me too! (And apparently to most others here too?)
I was going to look at those confusing bus cycles, using an only slightly
mis-addressed console, and wanted to first check that that console worked when
properly configured; so I plugged in it and an LSI-11/2 CPU - nothing.
Switched to a different CPU (maybe the first one died), _still_ nothing? So I
tried an -11/23, ODT worked! So, the console worked; the chances of two CPUs
that were working a week ago suddenly both dying seemed slim... what else
could it be?
And the /23 works with no memory! Odd. Will definitely have to make a note
of that LSI-11 behaviour on the CHWiki.
> I plugged in my 32kw module with my M8017-AA, and it fired right up to
> ODT without a hassle.
Well, it took a while, but we finally got there! Do let us know how it goes
with your next steps - and if you have an issue, let us know! (Hopefully, next
time, we won'tbe so clueless! :-)
PS: Might be useful to check that the DLV11-J works; having a stock of known-good
boards you can swap in is such a tool for QBUS debugging.
I have a few of these that need to be tested. I am certain they have not
been plugged in for many years.
Is the anything special I need to do before I just plug them in and turn
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Wow, I wasn't aware that the ODT console needed memory to run. Checking on
my board, it looks like the 4kw was disabled. I plugged in my 32kw module
with my M8017-AA, and it fired right up to ODT without a hassle. Seems that
was the issue all along.
On Fri, Jun 7, 2019, 3:08 PM Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> Hi, sorry I'm slow to do those tests; got distracted by the power
> card stuff.
> So I've just dicovered that in a system with _only_ an LSI-11/2,
> and a console, ODT doesn't start. I had to plug a memory card in
> as well for ODT to work. (Confused the dickens out of me!)
> Is the RAM on your CPU card configured off?
I think someone was looking for tape seals for 9 track tapes, a few weeks
If they can contact me offline, I have about 20 of varying sizes for
shipping cost or local pickup.
sieler at allegro.com
> From: Systems_Glitch
> I believe the big difference was in the current-supplying capability on
> the +15V rail -- 1A vs. 4A.
Ah, thanks for the tip.
I have an H742, so I was exable to examine it, and the 5409730 (difference
details on that below). The transformer may also be different (see below).
The other differences seem to be mechanical; a larger cooling fan on the 7420,
and the sheet-metal enclosure that holds the the power control board,
transformer and fan is in two parts, bolted together.
Interestingly, in light of your issue, the H7420's all have a fuse in the AC
supply line to the 5411086; it's mounted on the enclosure. Nothing in the
> I believe it was mentioned as an upgrade thing in one of the technical
> manuals I'd read some time ago.
If you happen to recall where that was, I'd be very interested to see it.
Upgrading from an H742 to an H7420 appears to be relatively simple; the pinout
on the Mate-N-Lok which carries the outputs from the power board (DEC's name
for it changes) is the same in both versions. (Have yet to look at the two
Mate-N-Lok's on either side of it; I guess those carry the ~30V AC to the
Upgrading an H742 _to_ an H7420 appears to be more problematic. To start with,
the power board is mounted vertically (on the inside face of the enclosure) in
the H7420, but horizontally (above the transformer) in the H742. Maybe they
changed the transformer too? Will have to check. It's also possible that was
caused by the switch to the larger fan. Anyway, the 5411086 might not fit
in the horizontal; plus the interface is different (see below).
> It would be easy to make up a new harness to swap one in place of the
> other, since the 5411086 goes to a Mate-n-Lok that plugs into the power
> distribution board.
Yes and no!
The 5409730 and the 5411086 are significantly different, mechanically. The
former doesn't have the edge connector (the one that burned out on you),
rather it has a short 12-wire pigtail to a female Mate-N-Lok which plugs into
a hole in the enclosure. That's for the _outputs_ - the AC input is in a
separate 4-pin Mate-n-Lok (physically exactly like the one on older disk
drives on PC's) which is mounted onto the board. (4 pins since there are two
differnet AC inputs - one pair is filtered through what seem to be hefty coils
in the input wiring.)
The harness used in the BA11-K is also significantly different from the one in
the H7420; the former has a male Mate-n-Lok, the latter is a female. The
pinout appears to be a subset on the BA11-K, only 9 of the 12 pins are wired;
assuming standard colour coding, the +8V DC is missing, as is the second
ACLO and DCLO.
Although, as you say, one could make a new harness. Speaking of which, do you
know of a source for the connector that goes onto the edge connector? (Some of
my BA11-K's are missing the harness.)
I'm slowly adding all this info to the CHWiki.
A friend at work picked up a nice MacPlus but no boot disk.? I have no
Mac compatible drive options here, so I am hoping someone might be able
to help.? I believe it can run OS6.0.8 on 800K floppies, but others
might know more.? Happy to pay for disk, work, and shipping.? Was going
to buy from BMOW, but they are out of stock.
brain at jbrain.comwww.jbrain.com
> From: Paul Anderson
>> (I also should check to see if the H742 uses the same 15V board; it
>> uses the same 'bricks', so it may.)
> Didn't the H7420 , which replaced the H742, use that also? The H742 uses
> a different one .
Oooh, good catch! The H742 uses a 5409730, but the H7420 does use the 5411086,
the same as in the H765. I always wondered what the difference was between the
H742 and H7420.
I wonder if the two boards (and thus the the power harness) have an identical
pinout, or not.
> From: Systems Glitch
> I finally fixed the power supply in my PDP-11/10S ... For those who
> have original 5411086s that haven't failed yet, you might want to
> make up a little pigtail with an inline fuse holder.
Congratulations, and a great blog write-up.
The issue you point out (lack of fusing for some components on the +15V
board) will of course apply to not just -11/10S's, but any -11 which uses
the H765, either for the CPU box (e.g. /04, /34) or for an expansion box.
This is important enough that I think I'll add a writeup to the CHWiki
article for that:
which restates the problem, and the proposed solution. (I also should check
to see if the H742 uses the same 15V board; it uses the same 'bricks', so
I have a Rockwell AIM-65 and back in the day did a lot of laboratory data acquisition and other things with them. I interfaced one to an atomic absorption graphite furnace to collect the readings and compute the parts per billion of various trace minerals in samples to translate 6 bit ticker tape code at 66.67 baud to 9600 baud ascii for a PDP-11/44. I did development on the AIM-65 and then transferred the code on EPROMs to Rockwell RM6500 single board cards usually. At home I made a ballistic chronometer with some aluminum foil and a resistor and my trusty AIM-65.
The most interesting project was an instrument I designed to measure how stable a vegetable oil was to oxidation. The AIM-65 would test 16 samples using a wire wrapped relay board to sequence through the signals, an Intersil 7109 12 bit A/D chip, a conductivity circuit, 32 Kbytes of RAM to hold data for plotting and a small 4 inch wide Radio Shack Pen Plotter. We built about five of them to use within our company, but had requests from customers for the instruments. Eventually, we out licensed the patents to an external company and I rewrote the software to run on a IBM PC. Later I rewrote the software in LabVIEW and it still runs in many labs where vegetable oils are refined or used. The analytical method for it is called the ?Oil Stability Index? and I wrote the official method (AOCS Cd12b-92) that defines it. If you search for ?Oil Stability Index? you?ll find it is widely used in the field. It is also sometimes called the Rancimat method after another automated instrument introduced later that works in the same way.
When I do get my AIM-65 out to play, it often is catatonic at first. I?ve found that (at least for mine) it is related to the inexpensive IC sockets Rockwell used in it. Usually some Deoxit or tuner cleaner on the sockets and reseating some ROM chips is all that is needed to get it going. That said you certainly could have more complicated issues as well.