20 Oct
2023
20 Oct
'23
8:40 p.m.
Hi,
I have a PDP-11/40 that I've wanted to restore for many years now. I got
it in the standard 21" cabinet but the power supplies were in a cardboard
box. I'm not certain how the power supply bundle mounts in the cab. Also
I'm missing the power supply cables. Do they use currently available Molex
connectors?
Could someone on the list perhaps take a picture or two to show me how the
supplies are supposed to mount in the rack? Also, a shot of the power
cable routing would help.
Thanks,
Marc Howard
21 Oct
21 Oct
1:03 p.m.
Vintagecomputer.net/digital/ hunt around there many pics of the power
supplies, various configurations.
On Sat, Oct 21, 2023, 3:55 AM Marc Howard via cctalk <cctalk(a)classiccmp.org>
wrote:
Hi,
I have a PDP-11/40 that I've wanted to restore for many years now. I got
it in the standard 21" cabinet but the power supplies were in a cardboard
box. I'm not certain how the power supply bundle mounts in the cab. Also
I'm missing the power supply cables. Do they use currently available Molex
connectors?
Could someone on the list perhaps take a picture or two to show me how the
supplies are supposed to mount in the rack? Also, a shot of the power
cable routing would help.
Thanks,
Marc Howard
5:37 p.m.
Here is one where I put the H742 on a block to make it easier to work on
https://vintagecomputer.net/digital/PDP11-40/H742_on_blocks.jpg
Here are the connectors to the regulators:
https://vintagecomputer.net/digital/PDP11-40/PDP11-40_DC-pwr-supplies.jpg
Here is the other end of the connectors
https://vintagecomputer.net/digital/PDP11-40/PDP11-40_fan_view.JPG
Plenty more pics here
https://vintagecomputer.net/digital/PDP11-40/
This is an abridged guide I made that's specific to the PDP 11/40, which I
used a lot
https://vintagecomputer.net/digital/PDP-11_Mainframe_Troubleshooting_Guide_…
I have a few other 11/40's that I have worked on, with separate pictures,
but the above is a good start.
Bill
On Sat, Oct 21, 2023 at 9:03 AM Bill Degnan <billdegnan(a)gmail.com> wrote:
Vintagecomputer.net/digital/ hunt around there many
pics of the power
supplies, various configurations.
On Sat, Oct 21, 2023, 3:55 AM Marc Howard via cctalk <
cctalk(a)classiccmp.org> wrote:
Hi,
I have a PDP-11/40 that I've wanted to restore for many years now. I got
it in the standard 21" cabinet but the power supplies were in a cardboard
box. I'm not certain how the power supply bundle mounts in the cab. Also
I'm missing the power supply cables. Do they use currently available
Molex
connectors?
Could someone on the list perhaps take a picture or two to show me how the
supplies are supposed to mount in the rack? Also, a shot of the power
cable routing would help.
Thanks,
Marc Howard
6 p.m.
That brings up a question that's rattled around my mind: On a 745 it's
rated to supply -15 volts at 10a, but it has two of the lines designated
as "+15 in". Where did the +15 come from, the other supplies put out
+20, +5, and -5?
Or does it put out +15 and -15 from the 20 volt AC input?
C
22 Oct
22 Oct
9:03 a.m.
I haven't looked at this in a long time, but I believe the H742 "bulk power
supply" puts out a voltage to the regulators to convert to the required
voltages. I don't remember what the voltage is.
Paul
On Sun, Oct 22, 2023 at 3:27 AM Chris Zach via cctalk <cctalk(a)classiccmp.org>
wrote:
https://vintagecomputer.net/digital/PDP11-40/PDP11-40_DC-pwr-supplies.jpg
That brings up a question that's rattled around my mind: On a 745 it's
rated to supply -15 volts at 10a, but it has two of the lines designated
as "+15 in". Where did the +15 come from, the other supplies put out
+20, +5, and -5?
Or does it put out +15 and -15 from the 20 volt AC input?
C
1:08 p.m.
Power 15 vs 20 is detailed in the hardware manual when to use which
On Sun, Oct 22, 2023, 4:27 AM Chris Zach via cctalk <cctalk(a)classiccmp.org>
wrote:
https://vintagecomputer.net/digital/PDP11-40/PDP11-40_DC-pwr-supplies.jpg
That brings up a question that's rattled around my mind: On a 745 it's
rated to supply -15 volts at 10a, but it has two of the lines designated
as "+15 in". Where did the +15 come from, the other supplies put out
+20, +5, and -5?
Or does it put out +15 and -15 from the 20 volt AC input?
C
398
days inactive
400
days old
5 comments
4 participants
participants (4)
-
Bill Degnan -
Chris Zach -
Marc Howard -
Paul Anderson