4 Sep
2014
4 Sep
'14
5:54 a.m.
Does anyone have the pinouts for the DECmate II power supplies? The
two PSU model numbers that I have are H7842A and H7842B, but I'd like
to know their pinouts in order to properly connect a load (or loads)
to them for "smoke testing" away from the computers themselves. They
are both 220W supplies according to their labels. (These PSUs may
have also been used in the DEC Rainbow.)
Does anyone, by chance, have the schematic(s) for these power
supplies? Other than close inspection for bulging/leaking capacitors
or obviously burnt/damaged components or areas on the PCB, what should
I look for to increase my chances of not allowing the smoke to escape?
(Also, I recently found a "vintage computer" discussion site where
they were trying to collect, preserve, & make *usable* images of any
DEC microfiche sets they could get. One guy said that he had a fiche
set that included the DECmate II. None of these fiche sets are
on-line yet as far as I can tell.)
Thanks,
Bob
4 Sep
4 Sep
7:13 a.m.
* Bob Vines <bobvines00 at gmail.com> [140904 10:02]:
[SNIP]
(Also, I recently found a "vintage computer"
discussion site where
they were trying to collect, preserve, & make *usable* images of any
DEC microfiche sets they could get. One guy said that he had a fiche
set that included the DECmate II. None of these fiche sets are
on-line yet as far as I can tell.)
Thanks,
Bob
Would you possibly pass along that site?
Thanks!
Todd
11:07 a.m.
Well, the easiest way to find the +5v rail is to look on the motherboard
for a ttl chip in the 74xxx range and lookup the datasheet to find its
vcc pin. a simple continuity test would give you the pin on the PSU. as
5v is one of the heavier loaded suply rails, you can put your dummyload
on there
simon
On 04-09-14 14:54, Bob Vines wrote:
Does anyone have the pinouts for the DECmate II power
supplies? The
two PSU model numbers that I have are H7842A and H7842B, but I'd like
to know their pinouts in order to properly connect a load (or loads)
to them for "smoke testing" away from the computers themselves. They
are both 220W supplies according to their labels. (These PSUs may
have also been used in the DEC Rainbow.)
Does anyone, by chance, have the schematic(s) for these power
supplies? Other than close inspection for bulging/leaking capacitors
or obviously burnt/damaged components or areas on the PCB, what should
I look for to increase my chances of not allowing the smoke to escape?
(Also, I recently found a "vintage computer" discussion site where
they were trying to collect, preserve, & make *usable* images of any
DEC microfiche sets they could get. One guy said that he had a fiche
set that included the DECmate II. None of these fiche sets are
on-line yet as far as I can tell.)
Thanks,
Bob
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
3:02 p.m.
The power supply of the Rainbow is, according to the print set, also a
H7841-A (120/240V) or H7841-B (120V only), so Tony would be right. It seems
the same case (BA-25).
I don't have the schematics or print set of the powersupply, but of course
the power connector is also on the mainboard.
So the pinout is:
1. ACOK H
2. IOWR4 L (connected via a jumper)
3. key
4. -12V
5. +12V
6. +12V
7. +5V
8. +5V
9. +5V
10. GND
11. GND
12. GND
13. GND
On Thu, Sep 4, 2014 at 9:00 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Does anyone have the pinouts for the DECmate II power supplies? The
Is this the same as a Rainbow PSU? If so, I should be able to find the
pinput of that.
-tony
5 Sep
5 Sep
12:56 p.m.
The power supply of the Rainbow is, according to the print set, also a
H7841-A (120/240V) or H7841-B (120V only), so Tony would be right. It seems
the same case (BA-25).
Some yeara ago I reverse-engioeered the complete Rainbow (including PSU,
all the option bords I have, etc).The SPU is vert conventioan (f0or DEC)
with a little lienar PSU to start it going.
I don't have the schematics or print set of the powersupply, but of course
the power connector is also on the mainboard.
So the pinout is:
1. ACOK H
2. IOWR4 L (connected via a jumper)
On my diagramss (not havign the benefit of the DEC printset), that's the
12V supply to the chopper control circuitry.
3. key
4. -12V
5. +12V
6. +12V
7. +5V
8. +5V
9. +5V
10. GND
11. GND
12. GND
13. GND
Power OK (pin 1) is an open-collector (actually open-drain, for some
reason hte switchign component in the PSU is an FET) output.
Mains comes in via the IEC plug/filter module, then via a circuit breaker
to a 3 pin conenctector that goes to the switch/fan assembly. A 4 pin
connecotr (only 2 pins used [1]) then takes mains from the swithc to the
PSU. There is a 6 pin connecotr (4 pins used) that carries 12V from the
PSU to power the fan and also a ujumper in series with the live side of
the maisn so tht the PSU can't run unless this conenctor is in place (i.e
unless the fan is pwoered).
So unless yuo have the switch/fliter unit fro mthe case poweri nup thsi
supply may not be trivial. If you do want to do this, I cam provide
details of all the connectors.
[1] The other 2 pins are a 115V feed from the pimrary side of the PSU
presuambly to allow the use of an AC fan.
BTW, is the Rainbow printset online anywhere? I've not found it.
-tony
3:39 p.m.
On Fri, Sep 5, 2014 at 9:56 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
BTW, is the Rainbow printset online anywhere? I've
not found it.
Yes. Somewhere on bitsavers.
http://bitsavers.trailing-edge.com/pdf/dec/rainbow/
--
Alex.
11:02 p.m.
Rainbow Printset? http://bitsavers.trailing-edge.com/pdf/dec/rainbow/
* MP01722_PC100*-*B_Rainbow_Schematic_Jul84*.*pdf*, 2013-11-20 14:54,
3.3M
Also:
https://archive.org/details/bitsavers_decrainbowwSchematicJul84_3508632
Up to the usual DEC standards; no PSU schematic, however.
On Fri, Sep 5, 2014 at 3:56 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
The power supply of the Rainbow is, according to the print set, also a
H7841-A (120/240V) or H7841-B (120V only), so Tony would be right. It
seems
the same case (BA-25).
Some yeara ago I reverse-engioeered the complete Rainbow (including PSU,
all the option bords I have, etc).The SPU is vert conventioan (f0or DEC)
with a little lienar PSU to start it going.
I don't have the schematics or print set of the powersupply, but of
course
the power connector is also on the mainboard.
So the pinout is:
1. ACOK H
2. IOWR4 L (connected via a jumper)
On my diagramss (not havign the benefit of the DEC printset), that's the
12V supply to the chopper control circuitry.
3. key
4. -12V
5. +12V
6. +12V
7. +5V
8. +5V
9. +5V
10. GND
11. GND
12. GND
13. GND
Power OK (pin 1) is an open-collector (actually open-drain, for some
reason hte switchign component in the PSU is an FET) output.
Mains comes in via the IEC plug/filter module, then via a circuit breaker
to a 3 pin conenctector that goes to the switch/fan assembly. A 4 pin
connecotr (only 2 pins used [1]) then takes mains from the swithc to the
PSU. There is a 6 pin connecotr (4 pins used) that carries 12V from the
PSU to power the fan and also a ujumper in series with the live side of
the maisn so tht the PSU can't run unless this conenctor is in place (i.e
unless the fan is pwoered).
So unless yuo have the switch/fliter unit fro mthe case poweri nup thsi
supply may not be trivial. If you do want to do this, I cam provide
details of all the connectors.
[1] The other 2 pins are a 115V feed from the pimrary side of the PSU
presuambly to allow the use of an AC fan.
BTW, is the Rainbow printset online anywhere? I've not found it.
-tony
6 Sep
6 Sep
1:06 p.m.
Rainbow Printset? http://bitsavers.trailing-edge.com/pdf/dec/rainbow/
* MP01722_PC100*-*B_Rainbow_Schematic_Jul84*.*pdf*, 2013-11-20 14:54,
3.3M
Also:
https://archive.org/details/bitsavers_decrainbowwSchematicJul84_3508632
Up to the usual DEC standards; no PSU schematic, however.
And no RMA board, grpahis board, keybaord, monitors, drives.
For all my diarams are my typcially hand-drawn scribble, I'll stick to
them....
My whole set of diagrams is over 100 sheets. I could be convinced to get
the PSU sheets scanend if somebody needs them or something like that...
-tony
11:45 p.m.
Well, DEC did have a habit of "parceling out" their documentation a bit.
Point taken that not everything is there.
If you do (or ever) catch the scanning-bug I'd certainly be interested in
the output :->.
On Sat, Sep 6, 2014 at 4:06 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Rainbow Printset? http://bitsavers.trailing-edge.com/pdf/dec/rainbow/
* MP01722_PC100*-*B_Rainbow_Schematic_Jul84*.*pdf*, 2013-11-20 14:54,
3.3M
Also:
https://archive.org/details/bitsavers_decrainbowwSchematicJul84_3508632
Up to the usual DEC standards; no PSU schematic, however.
And no RMA board, grpahis board, keybaord, monitors, drives.
For all my diarams are my typcially hand-drawn scribble, I'll stick to
them....
My whole set of diagrams is over 100 sheets. I could be convinced to get
the PSU sheets scanend if somebody needs them or something like that...
-tony
7 Sep
7 Sep
12:30 p.m.
Well, DEC did have a habit of "parceling out" their documentation a bit.
Point taken that not everything is there.
Sometimes they did. SOmetiems they didn't. The VT240 printset includes
the VR201 monitor and LK201 keyboard, for example.
I asusme there were otehr pritnsets for the extra bits of the Rainbow,
like the graphicvs board.
If you do (or ever) catch the scanning-bug I'd
certainly be interested in
the output :->.
I think I would do it a board/module at a time. Probably not worth doign
the CPU board the RX50 controller, VR201 or LK021, sinceofficial prints
for those exist. But the other add-on boards (had disk, RAM, graphics),
the RX50 drive (I have never seen a print for that [1]), the PSU and the
VR241 [2] would be worth getting scanned..
[1] The physical design of that drive is IMHO ridiculous. You can't get
to the stepper motor screws wit hall the PCBs in place. So you need a set
of extdenr cables (which AFAIK were never supplied) to do a head
alignment. ARGH!
[2] This is a Hitachi chassis. The PSU is even worse than most. It is
drive -- once the thing gets going, by a widnign on the flyback
transformer. So the PSU runs at the horizontal scan frequency, which
means ripple of nteh supply liens will be less noticeable (slight
shaddowing is a lot less of a problem if it doesn't drift across the screen).
There si a seaprate osicalltor to get it going, which is disabled when a
capacitor cahrges druing startup.
So for the PSU to run and stay running not only must the chopper, etc, be
OK, but slo the deflecion IC (on a thick film hybrid module, as is
typical of Hitachi), the orizontal output stage, the flyabck transfomrer,
etc. Sorting this montiro out is a right pain. Don't ask...
-tony
3759
days inactive
3762
days old
10 comments
6 participants
participants (6)
-
alex.van.denzel＠gmail.com -
ard＠p850ug1.demon.co.uk -
bobvines00＠gmail.com -
pbirkel＠gmail.com -
simski＠dds.nl -
tsg＠bonedaddy.net