1 Apr
2017
1 Apr
'17
12:33 p.m.
Hi guys !
My name is Dominique, 43 , from Belgium (I apologize in advance for my
approximate English). I join this forum under the recommendations of
Curious Marc. It seems there are people here who can help me to get back
to life the venerable machine that I have just recovered.
Some pictures of the beast :
http://www.actingmachines.com/classiccmp_forum/overview01.jpg
<http://www.zeltrax.com/classiccmp_forum/overview01.jpg>
http://www.actingmachines.com/classiccmp_forum/terminal.jpg
<http://www.zeltrax.com/classiccmp_forum/terminal.jpg>
http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg
<http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg>
It is a "Nixdor 600 series" (Apparently a Nixdorf 620/35), upgraded
several times until 1980, the CPU board is dated from this year. So I do
not know exactly what machine it is today the equivalent.
Anyway, the Nixdorf 620 is actually built by "Digital Computer Controls"
and after some researches it seems that it is a "DCC-116 E", the 17 slot
version of the "DCC-116" which Is a clone of the "Data General Nova
2/10".
http://www.actingmachines.com/classiccmp_forum/DCC.jpg
<http://www.zeltrax.com/classiccmp_forum/DCC.jpg>
The machine has five Key-stations (ENTREX DATA/SCOPE), a Mag-tape Pertec
8840A - A Disk Cartridge Diablo Model 40 and a big line drum printer
(Data Products model 2230), strange machine, there is a tape reader
inside the printer.
Here is the list of the boards I have with the references written on
them and their position in the machine:
*17 HEX 0 ? 15 ENTREX INC 62 00 01842 002 REV A*
*16 HEX 16 30 31 ENTREX INC 62 00 01842 002 REV A**
15 OPTION 2 Empty**
14 OPTION 1 Empty**
13 PRINTER ENTREX INC SN598**
12 TAPE 556/800 BPI 2433 LFI 213**
11 TAPE 1600 BPI Empty**
10 DISK 2456 00 MP-Kontroller D44an620
6393500215 2456 7 0 1577**
09 COMMO Empty**
08 SCANNER Scanner BD 2431 NCAG 54147.1.15 2431 02394**
07 MEM 1609 0 7 02616**
06 MEM Empty**
05 MEM 1609 0 8 02367**
04 MEM 1615 01 9 5596**
03 TTY Empty**
02 DO NOT USE Empty**
01 C.P. 1509 05 4 04436*
Concerning this I also ask a few questions:
*
What are the boards in slots 16 and 17 for?
*
I do not have a COM card, does that mean that I could not attempt a
serial transmission (type rs232) with this actual setup ?
*
I have no idea how many kilobytes are present, apparently there are
two core memory cards (8kb each? 16Kb each?), And non-core RAM board.
I first solved a problem with the power supply of the disk pack (bad HF
filter, short-circuited with the chassis, then it is also dead HF filter
in the "multi-plug" of the chassis that start to burn, once these
problems were solved, I cleaned the machine thoroughly, cleaning the
heads of readings with isopropyl alcohol, I Not yet cleaned the disc
himself which at first glance looks extremely clean, it has not left the
machine for 30 years.
http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg
<http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg>
I cleaned all the guides and the heads of the nine track tape Pertec
8840A. There was also a false contact in the ON-LINE button. I did a
first cleanup. I think there is always a problem with the HI-DEN button
used to set the magtape to 800BPI. It is currently ineffective, but I
have a doubt about the contacts of the lamp socket).
http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg
<http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg>
I then cleaned all the sockets and contacts at the boards of the
computer (logic and PSU)
http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg
<http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg>
Unfortunately, after a couple of hours, the "POWER FAIL" light has
started to light up. The problem here is that I have no schematics, it
is a modular power supply consisting of two elements:
http://www.actingmachines.com/classiccmp_forum/psus.jpg
<http://www.zeltrax.com/classiccmp_forum/psus.jpg>
One seems to be dedicated to the 15 VDC regulated, the second module is
in charge of the regulated 5VDC. Both elements have a "Power fail
module". When the machine is completely populated I now observe that the
+ 5VDC collapses at +1,9VDC.
Here what I measured out, you will also see what the boards of these
power supply look like.
http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg
<http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg>
http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg
<http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg>
Another thing I noted during my measurements, where I should (I think)
measure 15V, I have 18V, looking at the documentation on the NOVA 2 (4
slots), I observed according to the diagrams below That there is 18V but
before a zener diode and not at the level of connectors where there must
be 15VDC, should I warn me ? Would the diode be dead ?
I tried to join temporarily a secondary regulated power supply to
reinforce the + 5VDC so as to be sure that the problem did not come from
the logical part of the computer which checks these voltages and
triggers the Power Fail status. By coupling this external regulated
power supply, the computer restarts again, thus it is definitively the
power supply (or the comparator component(s) of the power fail module)
If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get again
the 5VDC, so the power has become "too weak" to power the computer when
it is fully populated.
Despite the temporary (and dangerous) look of my assembly with secondary
power supply, I could not stop myself and attempt a boot procedure via
the Cold Start button of the machine from the Disk Pack, and it works! :-)
http://www.zeltrax.com/classiccmp_forum/first_boot.jpg
It seems that I still have problems with the magtape, I had errors
trying to read a backup, but it may be simply because I still cannot get
the machine in 800BPI because of the capricious buttons of the front
panel. I also wrote a tape mark via a "WRITE TAPE MARK AND REWIND"
function, the mark seems to be written but does not do the Rewind,
however if I launch a REWIND only function, it executes the action
appropriately. In short, still things to investigate on this side.
Notes that the Operating system I used to make these tests is a very
limited OS named DIDOS which was distributed by Nixdorf for his 620
Serie. As the machine is a clone of DG NOVA 2/10, I wonder if the
computer is compatible with programs for the NOVA series of Data
General? So I wonder if the DCC-116 was compatible with the software for
NOVAs?
The other questions I ask myself at this point are the ways to transfer
softwares or bootable OS on this machine? I have no other disk pack on
another system but I have a nine track tape TU81 + connected to a VAX
4000-605A under OpenVMS 6.2, and I can put this computer on my network.
Do you think there's a way to make a bootable tape for my NOVA 2 clone
with the Pertec 8840A from a VAX 4000 with a TU81+ ?
Well, to continue, I have to repair this PSU, all information is
welcome, schematics would be ideal of course.
Finally, note that I am not a professional electronics technician, I
fixed a lot of machines basic knowledge, intuition, researches,
comparisons and logic, it is effective but full of limitations too, so
forgive me in advance If I do not always understand the possible answers
of electronics in "high engineering" mode ;-)
As a bonus, the V1 of a small video mounted with a few clips captured
during a session of my nocturnal repairs, during the first boot of the
machine since 3 decades ! (on my music, yes, I'm also a composer ;-) )
https://youtu.be/5jWOUtLKRIU
Thanks a lot to all in advance ;-)
Dominique
3:04 p.m.
On 04/01/2017 01:45 PM, Al Kossow via cctalk wrote:
On 4/1/17 12:33 PM, Dominique Carlier via cctalk wrote:
...and whatever you do, don't lose the tape. There will be
"interesting" consequences the moment some program does a form feed
(skip on channel 1)...
--Chuck
strange machine, there is a tape reader inside
the printer.
it is used to program vertical forms postioning. the format tape is
in a loop 
6:47 p.m.
Typically not, since with no tape it should act like all the holes are punched, yes?
Sent from my iPad
On Apr 1, 2017, at 18:04, Chuck Guzis via cctech
<cctech at classiccmp.org> wrote:
On 04/01/2017 01:45 PM, Al Kossow via cctalk
wrote:
...and whatever you do, don't lose the tape. There will be
"interesting" consequences the moment some program does a form feed
(skip on channel 1)...
--Chuck On 4/1/17 12:33 PM, Dominique Carlier via cctalk
wrote:
strange machine, there is a tape reader inside the printer.
it is used to program vertical forms postioning. the format tape is
in a loop 
17 May
17 May
9:32 p.m.
On 4/1/2017 6:47 PM, Jay Jaeger via cctech wrote:
Typically not, since with no tape it should act like
all the holes are punched, yes?
with no tape, the Data Products servo ran open loop.
You'd think what
you said was true, but IIRC, you didn't run them with no tape.
Later the 2230/60/90s had solid state and it wasn't a problem any more.
I don't know about this printer, but in the 80's a lot of the printers
worked similarly to the Data Products.
thanks
Jim
Sent from my iPad
On Apr 1, 2017, at 18:04, Chuck Guzis via cctech
<cctech at classiccmp.org> wrote:
On 04/01/2017 01:45 PM, Al Kossow via cctalk
wrote:
...and whatever you do, don't lose the tape. There will be
"interesting" consequences the moment some program does a form feed
(skip on channel 1)...
--Chuck On 4/1/17 12:33 PM, Dominique Carlier via cctalk
wrote:
strange machine, there is a tape reader inside the printer.
it is used to program
vertical forms postioning. the format tape is
in a loop 
1 Apr
1 Apr
8:28 p.m.
I do not have anything useful to say, but I liked your pictures and video. Congratulations
on a successful first boot!
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
2 Apr
2 Apr
5:11 p.m.
After the mess, ...
http://actingmachines.com/classiccmp_forum/mess01.jpg
... it was time to reorganize a cool place to continue this restoration :-)
http://actingmachines.com/classiccmp_forum/calm01.jpg
http://actingmachines.com/classiccmp_forum/calm02.jpg
Without the schematics of the two power supplies, I decided to follow
the tracks on the printed circuits boards from the area where I measured
the collapsed regulated 5vdc, I start to check the components and try to
understand the problem alone, I decided to check the 5 big capacitors
this one is a little bit high but OK
http://actingmachines.com/classiccmp_forum/capacheck2.jpg
YES ! I finally found a dead one, hourra!! :-)
http://actingmachines.com/classiccmp_forum/capacheck1.jpg
A 23000?f 15VDC used in the filtering of the regulated 5vdc, but...
finally no, unfortunately ... it was not the source of the power fail :-/
Tomorrow I continue my investigation and I will check the big capacitors
of the other power supply in charge of the 15V which is monitored and
possibly also the cause of the error message.
Dominique
3 Apr
3 Apr
1:05 p.m.
On 4/1/17 12:33 PM, Dominique Carlier via cctalk wrote:
[snip]
Anyway, the Nixdorf 620 is actually built by
"Digital Computer Controls"
and after some researches it seems that it is a "DCC-116 E", the 17 slot
version of the "DCC-116" which Is a clone of the "Data General Nova
2/10".
Er. My DCC-116 is more a clone of the mapped Nova 840 than the Nova 2,
with the DCC/Keronix "64Kword" hack that gives up more than one level of
indirect memory reference in exchange for having 16, rather than 15,
bits of logical memory reference.
[snip]
Here is the list of the boards I have with the
references written on
them and their position in the machine:
*17 HEX 0 ? 15 ENTREX INC 62 00 01842 002 REV A*
*16 HEX 16 30 31 ENTREX INC 62 00 01842 002 REV A**
15 OPTION 2 Empty**
14 OPTION 1 Empty**
13 PRINTER ENTREX INC SN598**
12 TAPE 556/800 BPI 2433 LFI 213**
11 TAPE 1600 BPI Empty**
10 DISK 2456 00 MP-Kontroller D44an620
6393500215 2456 7 0 1577**
09 COMMO Empty**
08 SCANNER Scanner BD 2431 NCAG 54147.1.15 2431 02394**
07 MEM 1609 0 7 02616**
06 MEM Empty**
05 MEM 1609 0 8 02367**
04 MEM 1615 01 9 5596**
03 TTY Empty**
02 DO NOT USE Empty**
01 C.P. 1509 05 4 04436*
Concerning this I also ask a few questions:
*
What are the boards in slots 16 and 17 for?
Packaging aside, this looks a lot like an Entrex 480 system, which was a
key-to-disk/tape system:
https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/ReportsAndViewer/…
My guess is you're looking at bespoke 16-port multiplexers for talking
to their terminals.
I do not have a COM card, does that mean that I
could not attempt a
serial transmission (type rs232) with this actual setup ?
IIRC the functionality of the basic I/O board normally found in slot
three is subsumed into the CPU card of the DCC116, so you should be fine
as long as you can find the signals on the back of the machine.
*
I have no idea how many kilobytes are present, apparently there are
two core memory cards (8kb each? 16Kb each?), And non-core RAM board.
It's a word oriented machine, so memory is sized in KW, not KB. You can
probably tell how big the boards are by looking at the physical address
jumpers; core boards were typically 8KW, MOS boards were typically 16 or
32KW, depending on vintage. Hint: The more jumpers, the smaller the board.
Unfortunately, after a couple of hours, the
"POWER FAIL" light has
started to light up. The problem here is that I have no schematics, it
is a modular power supply consisting of two elements:
http://www.actingmachines.com/classiccmp_forum/psus.jpg
<http://www.zeltrax.com/classiccmp_forum/psus.jpg>
I have no idea how this machine packages things, but in jumbo-chassis
Novas the lower PS generates five and 15 volt supplies, the top PS
generates only five. The reason for this is that the 15 volt supply is
only used by core memory boards and the memory bus is only available in
the lower chassis.
One seems to be dedicated to the 15 VDC regulated, the
second module is
in charge of the regulated 5VDC. Both elements have a "Power fail
module". When the machine is completely populated I now observe that the
+ 5VDC collapses at +1,9VDC.
Sounds like one of the +5V switchers is having issues.
[snip]
Another thing I noted during my measurements, where I should (I think)
measure 15V, I have 18V, looking at the documentation on the NOVA 2 (4
slots), I observed according to the diagrams below That there is 18V but
before a zener diode and not at the level of connectors where there must
be 15VDC, should I warn me ? Would the diode be dead ?
+/-5V and +15V but not -15V should be regulated. In the original DG
power supply both five and 15 volt supplies were derived from a common
+30V unregulated supply, but it's not clear that DCC followed that
model. It may be helpful to know that the +15V supply is not regulated
to 15V but temperature compensated downward with increasing temperature,
such that at 55C it's closer to 14.4V; this is done to maintain margins
on the core planes. The consequence is that you're probably looking at
something having drifted in the voltage divider that feeds the voltage
comparator or something having drifted in the temperature compensation
stuff (if it's actually there) rather than a simple zener gone bad.
I tried to join temporarily a secondary regulated power supply to
reinforce the + 5VDC so as to be sure that the problem did not come from
the logical part of the computer which checks these voltages and
triggers the Power Fail status. By coupling this external regulated
power supply, the computer restarts again, thus it is definitively the
power supply (or the comparator component(s) of the power fail module)
/POWER FAIL is asserted by the power supply itself, as is MEM OK.
If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get again
the 5VDC, so the power has become "too weak" to power the computer when
it is fully populated.
It's a switcher; look at the caps in the LC filter (downstream of the
series pass transistor) that, together with the inductor, form the
energy storage mechanism of the power supply; check the source supply as
well. The fact that it eventually comes back suggests that the
reference, comparator and pass device are probably functioning.
[snip]
Notes that the Operating system I used to make these
tests is a very
limited OS named DIDOS which was distributed by Nixdorf for his 620
Serie. As the machine is a clone of DG NOVA 2/10, I wonder if the
computer is compatible with programs for the NOVA series of Data
General? So I wonder if the DCC-116 was compatible with the software for
NOVAs?
Should be, as long as the machine isn't running in extended logical
address mode (my DCC has a front panel switch to enable/disable this
feature).
The other questions I ask myself at this point are the
ways to transfer
softwares or bootable OS on this machine? I have no other disk pack on
another system but I have a nine track tape TU81 + connected to a VAX
4000-605A under OpenVMS 6.2, and I can put this computer on my network.
Do you think there's a way to make a bootable tape for my NOVA 2 clone
with the Pertec 8840A from a VAX 4000 with a TU81+ ?
Probably. There's nothing magic about DG tape images.
Nice job on getting the machine to boot!
Cheers,
Chris
--
Christian Kennedy, Ph.D.
chris at mainecoon.com AF6AP | DB00000692 | PG00029419
http://www.mainecoon.com PGP KeyID 108DAB97
PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97
"Mr. McKittrick, after careful consideration?"
4 Apr
4 Apr
7:09 a.m.
Many thanks for these detailed answers ! :)
Indeed, I finally do not know exactly what Nova my DCC is the clone.
Another specialist suggested that it was rather a clone of NOVA 1200?
Note that in Nixdorf contracts for the 600 series, these machines were
sometimes updated with a new CPU over the years of service.
In the doubt here are pictures of the board in slot 01 dedicated to the CPU:
http://www.actingmachines.com/classiccmp_forum/cpu01.jpg
http://www.actingmachines.com/classiccmp_forum/cpu02.jpg
http://www.actingmachines.com/classiccmp_forum/cpu03.jpg
Do you have any idea what that is?
Concerning the PSU I will analyze your suggestions.
Concerning the memory, I analyzed more in detail, I think finally that
all the memory is core type, 1 X 16KW (it is marked on it) and 2 X 8KW
(according to the size of the core package in comparison with the 16KW
board). Thus a total of 32KW.
For transmission via serial port, unfortunately I do not have this
"basic board" in slot 3 (TTY), it's empty. Can we still find board like
this?
Dominique
Er. My DCC-116 is more a clone of the mapped Nova 840
than the Nova 2,
with the DCC/Keronix "64Kword" hack that gives up more than one level of
indirect memory reference in exchange for having 16, rather than 15,
bits of logical memory reference.
IIRC the functionality of the basic I/O board normally found in slot
three is subsumed into the CPU card of the DCC116, so you should be fine
as long as you can find the signals on the back of the machine.
It's a word oriented machine, so memory is sized in KW, not KB. You can
probably tell how big the boards are by looking at the physical address
jumpers; core boards were typically 8KW, MOS boards were typically 16 or
32KW, depending on vintage. Hint: The more jumpers, the smaller the board.
I have no idea how this machine packages things, but in jumbo-chassis
Novas the lower PS generates five and 15 volt supplies, the top PS
generates only five. The reason for this is that the 15 volt supply is
only used by core memory boards and the memory bus is only available in
the lower chassis.
Sounds like one of the +5V switchers is having issues.
+/-5V and +15V but not -15V should be regulated. In the original DG
power supply both five and 15 volt supplies were derived from a common
+30V unregulated supply, but it's not clear that DCC followed that
model. It may be helpful to know that the +15V supply is not regulated
to 15V but temperature compensated downward with increasing temperature,
such that at 55C it's closer to 14.4V; this is done to maintain margins
on the core planes. The consequence is that you're probably looking at
something having drifted in the voltage divider that feeds the voltage
comparator or something having drifted in the temperature compensation
stuff (if it's actually there) rather than a simple zener gone bad.
/POWER FAIL is asserted by the power supply itself, as is MEM OK.
It's a switcher; look at the caps in the LC filter (downstream of the
series pass transistor) that, together with the inductor, form the
energy storage mechanism of the power supply; check the source supply as
well. The fact that it eventually comes back suggests that the
reference, comparator and pass device are probably functioning.
Should be, as long as the machine isn't running in extended logical
address mode (my DCC has a front panel switch to enable/disable this
feature).
Nice job on getting the machine to boot!
Cheers,
Chris
7:38 a.m.
On 4/4/2017 7:09 AM, Dominique Carlier via cctalk wrote:
Concerning the PSU I will analyze your suggestions.
Concerning the memory, I analyzed more in detail, I think finally that
all the memory is core type, 1 X 16KW (it is marked on it) and 2 X 8KW
(according to the size of the core package in comparison with the 16KW
board). Thus a total of 32KW.
For transmission via serial port, unfortunately I do not have this
"basic board" in slot 3 (TTY), it's empty. Can we still find board
like this?
The design is 4 x 74181, which is potentially a 16 bit processor. The
74181 is a common ALU for systems, can the number of bits of 74181
adders are frequently an indicator of the width of the CPU.
The Serial port may be elsewhere. I'd look for RS232 level shifters
(probably 1488 and 1489s) and a UART on other boards. You may be out of
luck, but sometimes the serial may be in another area in systems.
Another sign to follow are the silver cans with oscillators, as they can
be for the system themselves, or for serial I/O.
thanks
Jim
12:47 p.m.
On 4/4/2017 7:09 AM, Dominique Carlier via cctalk
wrote:
> Concerning the memory, I analyzed more in detail,
I think finally that
> all the memory is core type, 1 X 16KW (it is marked on it) and 2 X 8KW
> (according to the size of the core package in comparison with the 16KW
> board). Thus a total of 32KW.
Yes, that would be a reasonable maximum configuration for this machine.
I yanked the CPU board out of my DCC 116 literally for the
first time, ever, which sent me down a rabbit hole.
Yes, it's a 1200 clone, which surprised me -- but the 1980 date on
the etch of your CPU is quite interesting. Turns out DCC literally
stole the prints for the 1200 and used it as the basis of the D-116 (the
also apparently ripped off the PDP-8 and PDP-11). At least in the case
of the D-116 it was literally a case of building to DG's prints, so much
so that the judge in the infringement case told DCC that had they
actually reverse engineered the 1200 they would have prevailed, but that
it was so obvious that they'd just done a punch of the machine that they
had to hand the injunction to DG.
Where this gets interesting is the timing. DG won the injunction in
September 1975, and it so crippled DCC that DG ended up acquiring DCC
and their product line in 1977 and eventually putting a stake in the
heart of the product line at the end of the 70s.
Does your CPU board have a DCC or DG copyright on it?
Making it stranger is the prohibition on putting anything in slot two
(mine has the same restriction). I'd have to look closely, but that
suggests that while the design ripped off the 1200 CPU it ripped off the
800 backplane (the 800 CPU takes two slots, the 1200 only one, and
thanks to the way the backplane is wired it's possible to run a 1200 CPU
in an 800 chassis).
Finding a basic I/O board shouldn't be difficult; you only need TTY (not
reader or punch controls), and while it would be nice you probably don't
need the RTC, either. Still, given the date of your machine the TTY
functionality /may/ be on the CPU card itself.
Is there a DB-9 connector somewhere on the rear bulkhead of the machine?
--
Christian Kennedy, Ph.D.
chris at mainecoon.com AF6AP | DB00000692 | PG00029419
http://www.mainecoon.com PGP KeyID 108DAB97
PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97
"Mr. McKittrick, after careful consideration?"
17 May
17 May
8:29 p.m.
Dominique,
I'm quite interested in seeing your Entrex/Nixdorf system restored. Please
keep us updated here. Nice work saving these rare items!
I've done some of my own work restoring a DG Nova-type system. (
http://Point4iris.com ). I'd love to see if there's any way I could help.
I'll read Christian Kennedy's response here, as he seems FAR more familiar
and knowledgeable than I am here, but if I can add value in any way, I
would love to.
Best,
-AJ
On Sat, Apr 1, 2017 at 12:33 PM, Dominique Carlier via cctalk <
cctalk at classiccmp.org> wrote:
Hi guys !
My name is Dominique, 43 , from Belgium (I apologize in advance for my
approximate English). I join this forum under the recommendations of
Curious Marc. It seems there are people here who can help me to get back to
life the venerable machine that I have just recovered.
Some pictures of the beast :
http://www.actingmachines.com/classiccmp_forum/overview01.jpg <
http://www.zeltrax.com/classiccmp_forum/overview01.jpg>
http://www.actingmachines.com/classiccmp_forum/terminal.jpg <
http://www.zeltrax.com/classiccmp_forum/terminal.jpg>
http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg <
http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg>
It is a "Nixdor 600 series" (Apparently a Nixdorf 620/35), upgraded
several times until 1980, the CPU board is dated from this year. So I do
not know exactly what machine it is today the equivalent.
Anyway, the Nixdorf 620 is actually built by "Digital Computer Controls"
and after some researches it seems that it is a "DCC-116 E", the 17 slot
version of the "DCC-116" which Is a clone of the "Data General Nova
2/10".
http://www.actingmachines.com/classiccmp_forum/DCC.jpg <
http://www.zeltrax.com/classiccmp_forum/DCC.jpg>
The machine has five Key-stations (ENTREX DATA/SCOPE), a Mag-tape Pertec
8840A - A Disk Cartridge Diablo Model 40 and a big line drum printer (Data
Products model 2230), strange machine, there is a tape reader inside the
printer.
Here is the list of the boards I have with the references written on them
and their position in the machine:
*17 HEX 0 ? 15 ENTREX INC 62 00 01842 002 REV A*
*16 HEX 16 30 31 ENTREX INC 62 00 01842 002 REV A**
15 OPTION 2 Empty**
14 OPTION 1 Empty**
13 PRINTER ENTREX INC SN598**
12 TAPE 556/800 BPI 2433 LFI 213**
11 TAPE 1600 BPI Empty**
10 DISK 2456 00 MP-Kontroller D44an620
6393500215 2456 7 0 1577**
09 COMMO Empty**
08 SCANNER Scanner BD 2431 NCAG 54147.1.15 2431 02394**
07 MEM 1609 0 7 02616**
06 MEM Empty**
05 MEM 1609 0 8 02367**
04 MEM 1615 01 9 5596**
03 TTY Empty**
02 DO NOT USE Empty**
01 C.P. 1509 05 4 04436*
Concerning this I also ask a few questions:
*
What are the boards in slots 16 and 17 for?
*
I do not have a COM card, does that mean that I could not attempt a
serial transmission (type rs232) with this actual setup ?
*
I have no idea how many kilobytes are present, apparently there are
two core memory cards (8kb each? 16Kb each?), And non-core RAM board.
I first solved a problem with the power supply of the disk pack (bad HF
filter, short-circuited with the chassis, then it is also dead HF filter in
the "multi-plug" of the chassis that start to burn, once these problems
were solved, I cleaned the machine thoroughly, cleaning the heads of
readings with isopropyl alcohol, I Not yet cleaned the disc himself which
at first glance looks extremely clean, it has not left the machine for 30
years.
http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg <
http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg>
I cleaned all the guides and the heads of the nine track tape Pertec
8840A. There was also a false contact in the ON-LINE button. I did a first
cleanup. I think there is always a problem with the HI-DEN button used to
set the magtape to 800BPI. It is currently ineffective, but I have a doubt
about the contacts of the lamp socket).
http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg <
http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg>
I then cleaned all the sockets and contacts at the boards of the computer
(logic and PSU)
http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg <
http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg>
Unfortunately, after a couple of hours, the "POWER FAIL" light has started
to light up. The problem here is that I have no schematics, it is a modular
power supply consisting of two elements:
http://www.actingmachines.com/classiccmp_forum/psus.jpg <
http://www.zeltrax.com/classiccmp_forum/psus.jpg>
One seems to be dedicated to the 15 VDC regulated, the second module is in
charge of the regulated 5VDC. Both elements have a "Power fail module".
When the machine is completely populated I now observe that the + 5VDC
collapses at +1,9VDC.
Here what I measured out, you will also see what the boards of these power
supply look like.
http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg <
http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg>
http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg <
http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg>
Another thing I noted during my measurements, where I should (I think)
measure 15V, I have 18V, looking at the documentation on the NOVA 2 (4
slots), I observed according to the diagrams below That there is 18V but
before a zener diode and not at the level of connectors where there must be
15VDC, should I warn me ? Would the diode be dead ?
I tried to join temporarily a secondary regulated power supply to
reinforce the + 5VDC so as to be sure that the problem did not come from
the logical part of the computer which checks these voltages and triggers
the Power Fail status. By coupling this external regulated power supply,
the computer restarts again, thus it is definitively the power supply (or
the comparator component(s) of the power fail module)
If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get again
the 5VDC, so the power has become "too weak" to power the computer when it
is fully populated.
Despite the temporary (and dangerous) look of my assembly with secondary
power supply, I could not stop myself and attempt a boot procedure via the
Cold Start button of the machine from the Disk Pack, and it works! :-)
http://www.zeltrax.com/classiccmp_forum/first_boot.jpg
It seems that I still have problems with the magtape, I had errors trying
to read a backup, but it may be simply because I still cannot get the
machine in 800BPI because of the capricious buttons of the front panel. I
also wrote a tape mark via a "WRITE TAPE MARK AND REWIND" function, the
mark seems to be written but does not do the Rewind, however if I launch a
REWIND only function, it executes the action appropriately. In short, still
things to investigate on this side.
Notes that the Operating system I used to make these tests is a very
limited OS named DIDOS which was distributed by Nixdorf for his 620 Serie.
As the machine is a clone of DG NOVA 2/10, I wonder if the computer is
compatible with programs for the NOVA series of Data General? So I wonder
if the DCC-116 was compatible with the software for NOVAs?
The other questions I ask myself at this point are the ways to transfer
softwares or bootable OS on this machine? I have no other disk pack on
another system but I have a nine track tape TU81 + connected to a VAX
4000-605A under OpenVMS 6.2, and I can put this computer on my network. Do
you think there's a way to make a bootable tape for my NOVA 2 clone with
the Pertec 8840A from a VAX 4000 with a TU81+ ?
Well, to continue, I have to repair this PSU, all information is welcome,
schematics would be ideal of course.
Finally, note that I am not a professional electronics technician, I fixed
a lot of machines basic knowledge, intuition, researches, comparisons and
logic, it is effective but full of limitations too, so forgive me in
advance If I do not always understand the possible answers of electronics
in "high engineering" mode ;-)
As a bonus, the V1 of a small video mounted with a few clips captured
during a session of my nocturnal repairs, during the first boot of the
machine since 3 decades ! (on my music, yes, I'm also a composer ;-) )
https://youtu.be/5jWOUtLKRIU
Thanks a lot to all in advance ;-)
Dominique
--
Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
https://www.linkedin.com/in/aj-palmgren-4a085516/
9:05 p.m.
My search for this was prompted by my seeing one on eBay:
http://www.ebay.com/itm/282462822861
Did anyone here purchase it, or know who did? Just curious, since these
seem so rare and interesting.
Best,
-AJ
On Wed, May 17, 2017 at 8:29 PM, AJ Palmgren <microtechdart at gmail.com>
wrote:
Dominique,
I'm quite interested in seeing your Entrex/Nixdorf system restored.
Please keep us updated here. Nice work saving these rare items!
I've done some of my own work restoring a DG Nova-type system. (
http://Point4iris.com ). I'd love to see if there's any way I could help.
I'll read Christian Kennedy's response here, as he seems FAR more familiar
and knowledgeable than I am here, but if I can add value in any way, I
would love to.
Best,
-AJ
On Sat, Apr 1, 2017 at 12:33 PM, Dominique Carlier via cctalk <
cctalk at classiccmp.org> wrote:
--
Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
https://www.linkedin.com/in/aj-palmgren-4a085516/
Hi guys !
My name is Dominique, 43 , from Belgium (I apologize in advance for my
approximate English). I join this forum under the recommendations of
Curious Marc. It seems there are people here who can help me to get back to
life the venerable machine that I have just recovered.
Some pictures of the beast :
http://www.actingmachines.com/classiccmp_forum/overview01.jpg <
http://www.zeltrax.com/classiccmp_forum/overview01.jpg>
http://www.actingmachines.com/classiccmp_forum/terminal.jpg <
http://www.zeltrax.com/classiccmp_forum/terminal.jpg>
http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg <
http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg>
It is a "Nixdor 600 series" (Apparently a Nixdorf 620/35), upgraded
several times until 1980, the CPU board is dated from this year. So I do
not know exactly what machine it is today the equivalent.
Anyway, the Nixdorf 620 is actually built by "Digital Computer Controls"
and after some researches it seems that it is a "DCC-116 E", the 17 slot
version of the "DCC-116" which Is a clone of the "Data General Nova
2/10".
http://www.actingmachines.com/classiccmp_forum/DCC.jpg <
http://www.zeltrax.com/classiccmp_forum/DCC.jpg>
The machine has five Key-stations (ENTREX DATA/SCOPE), a Mag-tape Pertec
8840A - A Disk Cartridge Diablo Model 40 and a big line drum printer (Data
Products model 2230), strange machine, there is a tape reader inside the
printer.
Here is the list of the boards I have with the references written on them
and their position in the machine:
*17 HEX 0 ? 15 ENTREX INC 62 00 01842 002 REV A*
*16 HEX 16 30 31 ENTREX INC 62 00 01842 002 REV A**
15 OPTION 2 Empty**
14 OPTION 1 Empty**
13 PRINTER ENTREX INC SN598**
12 TAPE 556/800 BPI 2433 LFI 213**
11 TAPE 1600 BPI Empty**
10 DISK 2456 00 MP-Kontroller D44an620
6393500215 2456 7 0 1577**
09 COMMO Empty**
08 SCANNER Scanner BD 2431 NCAG 54147.1.15 2431
02394**
07 MEM 1609 0 7 02616**
06 MEM Empty**
05 MEM 1609 0 8 02367**
04 MEM 1615 01 9 5596**
03 TTY Empty**
02 DO NOT USE Empty**
01 C.P. 1509 05 4 04436*
Concerning this I also ask a few questions:
*
What are the boards in slots 16 and 17 for?
*
I do not have a COM card, does that mean that I could not attempt a
serial transmission (type rs232) with this actual setup ?
*
I have no idea how many kilobytes are present, apparently there are
two core memory cards (8kb each? 16Kb each?), And non-core RAM board.
I first solved a problem with the power supply of the disk pack (bad HF
filter, short-circuited with the chassis, then it is also dead HF filter in
the "multi-plug" of the chassis that start to burn, once these problems
were solved, I cleaned the machine thoroughly, cleaning the heads of
readings with isopropyl alcohol, I Not yet cleaned the disc himself which
at first glance looks extremely clean, it has not left the machine for 30
years.
http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg <
http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg>
I cleaned all the guides and the heads of the nine track tape Pertec
8840A. There was also a false contact in the ON-LINE button. I did a first
cleanup. I think there is always a problem with the HI-DEN button used to
set the magtape to 800BPI. It is currently ineffective, but I have a doubt
about the contacts of the lamp socket).
http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg <
http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg>
I then cleaned all the sockets and contacts at the boards of the computer
(logic and PSU)
http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg <
http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg>
Unfortunately, after a couple of hours, the "POWER FAIL" light has
started to light up. The problem here is that I have no schematics, it is a
modular power supply consisting of two elements:
http://www.actingmachines.com/classiccmp_forum/psus.jpg <
http://www.zeltrax.com/classiccmp_forum/psus.jpg>
One seems to be dedicated to the 15 VDC regulated, the second module is
in charge of the regulated 5VDC. Both elements have a "Power fail module".
When the machine is completely populated I now observe that the + 5VDC
collapses at +1,9VDC.
Here what I measured out, you will also see what the boards of these
power supply look like.
http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg <
http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg>
http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg <
http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg>
Another thing I noted during my measurements, where I should (I think)
measure 15V, I have 18V, looking at the documentation on the NOVA 2 (4
slots), I observed according to the diagrams below That there is 18V but
before a zener diode and not at the level of connectors where there must be
15VDC, should I warn me ? Would the diode be dead ?
I tried to join temporarily a secondary regulated power supply to
reinforce the + 5VDC so as to be sure that the problem did not come from
the logical part of the computer which checks these voltages and triggers
the Power Fail status. By coupling this external regulated power supply,
the computer restarts again, thus it is definitively the power supply (or
the comparator component(s) of the power fail module)
If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get again
the 5VDC, so the power has become "too weak" to power the computer when it
is fully populated.
Despite the temporary (and dangerous) look of my assembly with secondary
power supply, I could not stop myself and attempt a boot procedure via the
Cold Start button of the machine from the Disk Pack, and it works! :-)
http://www.zeltrax.com/classiccmp_forum/first_boot.jpg
It seems that I still have problems with the magtape, I had errors trying
to read a backup, but it may be simply because I still cannot get the
machine in 800BPI because of the capricious buttons of the front panel. I
also wrote a tape mark via a "WRITE TAPE MARK AND REWIND" function, the
mark seems to be written but does not do the Rewind, however if I launch a
REWIND only function, it executes the action appropriately. In short, still
things to investigate on this side.
Notes that the Operating system I used to make these tests is a very
limited OS named DIDOS which was distributed by Nixdorf for his 620 Serie.
As the machine is a clone of DG NOVA 2/10, I wonder if the computer is
compatible with programs for the NOVA series of Data General? So I wonder
if the DCC-116 was compatible with the software for NOVAs?
The other questions I ask myself at this point are the ways to transfer
softwares or bootable OS on this machine? I have no other disk pack on
another system but I have a nine track tape TU81 + connected to a VAX
4000-605A under OpenVMS 6.2, and I can put this computer on my network. Do
you think there's a way to make a bootable tape for my NOVA 2 clone with
the Pertec 8840A from a VAX 4000 with a TU81+ ?
Well, to continue, I have to repair this PSU, all information is welcome,
schematics would be ideal of course.
Finally, note that I am not a professional electronics technician, I
fixed a lot of machines basic knowledge, intuition, researches, comparisons
and logic, it is effective but full of limitations too, so forgive me in
advance If I do not always understand the possible answers of electronics
in "high engineering" mode ;-)
As a bonus, the V1 of a small video mounted with a few clips captured
during a session of my nocturnal repairs, during the first boot of the
machine since 3 decades ! (on my music, yes, I'm also a composer ;-) )
https://youtu.be/5jWOUtLKRIU
Thanks a lot to all in advance ;-)
Dominique
--
Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
https://www.linkedin.com/in/aj-palmgren-4a085516/
18 May
18 May
6:08 a.m.
Hi,
I saw this ad but the shipping costs until Belgium decided me to react
as if I had not seen anything ^^
It's a pity, I would have taken a few boards.
On 18/05/2017 06:05, AJ Palmgren wrote:
My search for this was prompted by my seeing one on
eBay:
http://www.ebay.com/itm/282462822861
Did anyone here purchase it, or know who did? Just curious, since
these seem so rare and interesting.
Best,
-AJ
On Wed, May 17, 2017 at 8:29 PM, AJ Palmgren <microtechdart at gmail.com
<mailto:microtechdart at gmail.com>> wrote:
Dominique,
I'm quite interested in seeing your Entrex/Nixdorf system
restored. Please keep us updated here. Nice work saving these
rare items!
I've done some of my own work restoring a DG Nova-type system. (
http://Point4iris.com ). I'd love to see if there's any way I
could help.
I'll read Christian Kennedy's response here, as he seems FAR more
familiar and knowledgeable than I am here, but if I can add value
in any way, I would love to.
Best,
-AJ
On Sat, Apr 1, 2017 at 12:33 PM, Dominique Carlier via cctalk
<cctalk at classiccmp.org <mailto:cctalk at classiccmp.org>> wrote:
Hi guys !
My name is Dominique, 43 , from Belgium (I apologize in
advance for my approximate English). I join this forum under
the recommendations of Curious Marc. It seems there are people
here who can help me to get back to life the venerable machine
that I have just recovered.
Some pictures of the beast :
http://www.actingmachines.com/classiccmp_forum/overview01.jpg
<http://www.actingmachines.com/classiccmp_forum/overview01.jpg>
<http://www.zeltrax.com/classiccmp_forum/overview01.jpg
<http://www.zeltrax.com/classiccmp_forum/overview01.jpg>>
http://www.actingmachines.com/classiccmp_forum/terminal.jpg
<http://www.actingmachines.com/classiccmp_forum/terminal.jpg>
<http://www.zeltrax.com/classiccmp_forum/terminal.jpg
<http://www.zeltrax.com/classiccmp_forum/terminal.jpg>>
http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg
<http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg>
<http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg
<http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg>>
It is a "Nixdor 600 series" (Apparently a Nixdorf 620/35),
upgraded several times until 1980, the CPU board is dated from
this year. So I do not know exactly what machine it is today
the equivalent.
Anyway, the Nixdorf 620 is actually built by "Digital Computer
Controls" and after some researches it seems that it is a
"DCC-116 E", the 17 slot version of the "DCC-116" which Is a
clone of the "Data General Nova 2/10".
http://www.actingmachines.com/classiccmp_forum/DCC.jpg
<http://www.actingmachines.com/classiccmp_forum/DCC.jpg>
<http://www.zeltrax.com/classiccmp_forum/DCC.jpg
<http://www.zeltrax.com/classiccmp_forum/DCC.jpg>>
The machine has five Key-stations (ENTREX DATA/SCOPE), a
Mag-tape Pertec 8840A - A Disk Cartridge Diablo Model 40 and a
big line drum printer (Data Products model 2230), strange
machine, there is a tape reader inside the printer.
Here is the list of the boards I have with the references
written on them and their position in the machine:
*17 HEX 0 ? 15 ENTREX INC 62 00 01842 002
REV A*
*16 HEX 16 30 31 ENTREX INC 62 00 01842 002 REV A**
15 OPTION 2 Empty**
14 OPTION 1 Empty**
13 PRINTER ENTREX INC SN598**
12 TAPE 556/800 BPI 2433 LFI 213**
11 TAPE 1600 BPI Empty**
10 DISK 2456 00 MP-Kontroller
D44an620 6393500215 <tel:6393500215> 2456 7 0 1577**
09 COMMO Empty**
08 SCANNER Scanner BD 2431 NCAG 54147.1.15
2431 02394**
07 MEM 1609 0 7 02616**
06 MEM Empty**
05 MEM 1609 0 8 02367**
04 MEM 1615 01 9 5596**
03 TTY Empty**
02 DO NOT USE Empty**
01 C.P. 1509 05 4 04436*
Concerning this I also ask a few questions:
*
What are the boards in slots 16 and 17 for?
*
I do not have a COM card, does that mean that I could not
attempt a
serial transmission (type rs232) with this actual setup ?
*
I have no idea how many kilobytes are present, apparently
there are
two core memory cards (8kb each? 16Kb each?), And non-core
RAM board.
I first solved a problem with the power supply of the disk
pack (bad HF filter, short-circuited with the chassis, then it
is also dead HF filter in the "multi-plug" of the chassis that
start to burn, once these problems were solved, I cleaned the
machine thoroughly, cleaning the heads of readings with
isopropyl alcohol, I Not yet cleaned the disc himself which at
first glance looks extremely clean, it has not left the
machine for 30 years.
http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg
<http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg>
<http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg
<http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg>>
I cleaned all the guides and the heads of the nine track tape
Pertec 8840A. There was also a false contact in the ON-LINE
button. I did a first cleanup. I think there is always a
problem with the HI-DEN button used to set the magtape to
800BPI. It is currently ineffective, but I have a doubt about
the contacts of the lamp socket).
http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg
<http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg>
<http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg
<http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg>>
I then cleaned all the sockets and contacts at the boards of
the computer (logic and PSU)
http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg
<http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg>
<http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg
<http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg>>
Unfortunately, after a couple of hours, the "POWER FAIL" light
has started to light up. The problem here is that I have no
schematics, it is a modular power supply consisting of two
elements:
http://www.actingmachines.com/classiccmp_forum/psus.jpg
<http://www.actingmachines.com/classiccmp_forum/psus.jpg>
<http://www.zeltrax.com/classiccmp_forum/psus.jpg
<http://www.zeltrax.com/classiccmp_forum/psus.jpg>>
One seems to be dedicated to the 15 VDC regulated, the second
module is in charge of the regulated 5VDC. Both elements have
a "Power fail module". When the machine is completely
populated I now observe that the + 5VDC collapses at +1,9VDC.
Here what I measured out, you will also see what the boards of
these power supply look like.
http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg
<http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg>
<http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg
<http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg>>
http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg
<http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg>
<http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg
<http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg>>
Another thing I noted during my measurements, where I should
(I think) measure 15V, I have 18V, looking at the
documentation on the NOVA 2 (4 slots), I observed according to
the diagrams below That there is 18V but before a zener diode
and not at the level of connectors where there must be 15VDC,
should I warn me ? Would the diode be dead ?
I tried to join temporarily a secondary regulated power supply
to reinforce the + 5VDC so as to be sure that the problem did
not come from the logical part of the computer which checks
these voltages and triggers the Power Fail status. By coupling
this external regulated power supply, the computer restarts
again, thus it is definitively the power supply (or the
comparator component(s) of the power fail module)
If I removes all the boards (printer, core memory, scanner,
disk controller, etc.), the Power Fail light eventually goes
out, I get again the 5VDC, so the power has become "too weak"
to power the computer when it is fully populated.
Despite the temporary (and dangerous) look of my assembly with
secondary power supply, I could not stop myself and attempt a
boot procedure via the Cold Start button of the machine from
the Disk Pack, and it works! :-)
http://www.zeltrax.com/classiccmp_forum/first_boot.jpg
<http://www.zeltrax.com/classiccmp_forum/first_boot.jpg>
It seems that I still have problems with the magtape, I had
errors trying to read a backup, but it may be simply because I
still cannot get the machine in 800BPI because of the
capricious buttons of the front panel. I also wrote a tape
mark via a "WRITE TAPE MARK AND REWIND" function, the mark
seems to be written but does not do the Rewind, however if I
launch a REWIND only function, it executes the action
appropriately. In short, still things to investigate on this side.
Notes that the Operating system I used to make these tests is
a very limited OS named DIDOS which was distributed by Nixdorf
for his 620 Serie. As the machine is a clone of DG NOVA 2/10,
I wonder if the computer is compatible with programs for the
NOVA series of Data General? So I wonder if the DCC-116 was
compatible with the software for NOVAs?
The other questions I ask myself at this point are the ways to
transfer softwares or bootable OS on this machine? I have no
other disk pack on another system but I have a nine track tape
TU81 + connected to a VAX 4000-605A under OpenVMS 6.2, and I
can put this computer on my network. Do you think there's a
way to make a bootable tape for my NOVA 2 clone with the
Pertec 8840A from a VAX 4000 with a TU81+ ?
Well, to continue, I have to repair this PSU, all information
is welcome, schematics would be ideal of course.
Finally, note that I am not a professional electronics
technician, I fixed a lot of machines basic knowledge,
intuition, researches, comparisons and logic, it is effective
but full of limitations too, so forgive me in advance If I do
not always understand the possible answers of electronics in
"high engineering" mode ;-)
As a bonus, the V1 of a small video mounted with a few clips
captured during a session of my nocturnal repairs, during the
first boot of the machine since 3 decades ! (on my music, yes,
I'm also a composer ;-) )
https://youtu.be/5jWOUtLKRIU
Thanks a lot to all in advance ;-)
Dominique
--
Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
<https://www.facebook.com/profile.php?id=100010931314283>
https://www.linkedin.com/in/aj-palmgren-4a085516/
<https://www.linkedin.com/in/aj-palmgren-4a085516/>
--
Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
https://www.linkedin.com/in/aj-palmgren-4a085516/
6:21 a.m.
Hi all,
Sorry for this long wait. Because of some family problems combined with
a big professional project I had to put this project on hold. However I
intend to continue this restoration with detailed photos and all the
continuation of the adventure with a lot of informations ;-)
Since my lasts posts on cctalk I received the schematics of a DG Nova
1200, all the information I needed to repair the power supply are in
this documentation. However it is a very complex system of voltage
regulation and because I am not a professional electronics technician, I
have not yet found the origin of the power loss that results in the
state of "Power Fail" (To be precise : it is when the computer is
populated with more than 2 or 3 boards. Any board).
It is also because i have not currently enough time to search the
problem in "blind mode" : De-solder all the transistors to search and
evaluate a possible leaking, replace all the suspect capacitor (just to
replace the big ones it cost more than 200$) etc..
But be patient ;-) I'm determined to continue the adventure soon as
possible.
Thanks for your interest !
Dominique
On 18/05/2017 05:29, AJ Palmgren wrote:
Dominique,
I'm quite interested in seeing your Entrex/Nixdorf system restored.
Please keep us updated here. Nice work saving these rare items!
I've done some of my own work restoring a DG Nova-type system. (
http://Point4iris.com ). I'd love to see if there's any way I could help.
I'll read Christian Kennedy's response here, as he seems FAR more
familiar and knowledgeable than I am here, but if I can add value in
any way, I would love to.
Best,
-AJ
On Sat, Apr 1, 2017 at 12:33 PM, Dominique Carlier via cctalk
<cctalk at classiccmp.org <mailto:cctalk at classiccmp.org>> wrote:
Hi guys !
My name is Dominique, 43 , from Belgium (I apologize in advance
for my approximate English). I join this forum under the
recommendations of Curious Marc. It seems there are people here
who can help me to get back to life the venerable machine that I
have just recovered.
Some pictures of the beast :
http://www.actingmachines.com/classiccmp_forum/overview01.jpg
<http://www.actingmachines.com/classiccmp_forum/overview01.jpg>
<http://www.zeltrax.com/classiccmp_forum/overview01.jpg
<http://www.zeltrax.com/classiccmp_forum/overview01.jpg>>
http://www.actingmachines.com/classiccmp_forum/terminal.jpg
<http://www.actingmachines.com/classiccmp_forum/terminal.jpg>
<http://www.zeltrax.com/classiccmp_forum/terminal.jpg
<http://www.zeltrax.com/classiccmp_forum/terminal.jpg>>
http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg
<http://www.actingmachines.com/classiccmp_forum/comrack_closeup.jpg>
<http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg
<http://www.zeltrax.com/classiccmp_forum/comrack_closeup.jpg>>
It is a "Nixdor 600 series" (Apparently a Nixdorf 620/35),
upgraded several times until 1980, the CPU board is dated from
this year. So I do not know exactly what machine it is today the
equivalent.
Anyway, the Nixdorf 620 is actually built by "Digital Computer
Controls" and after some researches it seems that it is a "DCC-116
E", the 17 slot version of the "DCC-116" which Is a clone of the
"Data General Nova 2/10".
http://www.actingmachines.com/classiccmp_forum/DCC.jpg
<http://www.actingmachines.com/classiccmp_forum/DCC.jpg>
<http://www.zeltrax.com/classiccmp_forum/DCC.jpg
<http://www.zeltrax.com/classiccmp_forum/DCC.jpg>>
The machine has five Key-stations (ENTREX DATA/SCOPE), a Mag-tape
Pertec 8840A - A Disk Cartridge Diablo Model 40 and a big line
drum printer (Data Products model 2230), strange machine, there is
a tape reader inside the printer.
Here is the list of the boards I have with the references written
on them and their position in the machine:
*17 HEX 0 ? 15 ENTREX INC 62 00 01842 002 REV A*
*16 HEX 16 30 31 ENTREX INC 62 00 01842 002 REV A**
15 OPTION 2 Empty**
14 OPTION 1 Empty**
13 PRINTER ENTREX INC SN598**
12 TAPE 556/800 BPI 2433 LFI 213**
11 TAPE 1600 BPI Empty**
10 DISK 2456 00 MP-Kontroller
D44an620 6393500215 <tel:6393500215> 2456 7 0 1577**
09 COMMO Empty**
08 SCANNER Scanner BD 2431 NCAG 54147.1.15
2431 02394**
07 MEM 1609 0 7 02616**
06 MEM Empty**
05 MEM 1609 0 8 02367**
04 MEM 1615 01 9 5596**
03 TTY Empty**
02 DO NOT USE Empty**
01 C.P. 1509 05 4 04436*
Concerning this I also ask a few questions:
*
What are the boards in slots 16 and 17 for?
*
I do not have a COM card, does that mean that I could not attempt a
serial transmission (type rs232) with this actual setup ?
*
I have no idea how many kilobytes are present, apparently there are
two core memory cards (8kb each? 16Kb each?), And non-core RAM
board.
I first solved a problem with the power supply of the disk pack
(bad HF filter, short-circuited with the chassis, then it is also
dead HF filter in the "multi-plug" of the chassis that start to
burn, once these problems were solved, I cleaned the machine
thoroughly, cleaning the heads of readings with isopropyl alcohol,
I Not yet cleaned the disc himself which at first glance looks
extremely clean, it has not left the machine for 30 years.
http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg
<http://www.actingmachines.com/classiccmp_forum/disckpack01.jpg>
<http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg
<http://www.zeltrax.com/classiccmp_forum/disckpack01.jpg>>
I cleaned all the guides and the heads of the nine track tape
Pertec 8840A. There was also a false contact in the ON-LINE
button. I did a first cleanup. I think there is always a problem
with the HI-DEN button used to set the magtape to 800BPI. It is
currently ineffective, but I have a doubt about the contacts of
the lamp socket).
http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg
<http://www.actingmachines.com/classiccmp_forum/ninetrack.jpg>
<http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg
<http://www.zeltrax.com/classiccmp_forum/ninetrack.jpg>>
I then cleaned all the sockets and contacts at the boards of the
computer (logic and PSU)
http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg
<http://www.actingmachines.com/classiccmp_forum/clean_contact.jpg>
<http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg
<http://www.zeltrax.com/classiccmp_forum/clean_contact.jpg>>
Unfortunately, after a couple of hours, the "POWER FAIL" light has
started to light up. The problem here is that I have no
schematics, it is a modular power supply consisting of two elements:
http://www.actingmachines.com/classiccmp_forum/psus.jpg
<http://www.actingmachines.com/classiccmp_forum/psus.jpg>
<http://www.zeltrax.com/classiccmp_forum/psus.jpg
<http://www.zeltrax.com/classiccmp_forum/psus.jpg>>
One seems to be dedicated to the 15 VDC regulated, the second
module is in charge of the regulated 5VDC. Both elements have a
"Power fail module". When the machine is completely populated I
now observe that the + 5VDC collapses at +1,9VDC.
Here what I measured out, you will also see what the boards of
these power supply look like.
http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg
<http://www.actingmachines.com/classiccmp_forum/psu_module_1.jpg>
<http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg
<http://www.zeltrax.com/classiccmp_forum/psu_module_1.jpg>>
http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg
<http://www.actingmachines.com/classiccmp_forum/psu_module_2.jpg>
<http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg
<http://www.zeltrax.com/classiccmp_forum/psu_module_2.jpg>>
Another thing I noted during my measurements, where I should (I
think) measure 15V, I have 18V, looking at the documentation on
the NOVA 2 (4 slots), I observed according to the diagrams below
That there is 18V but before a zener diode and not at the level of
connectors where there must be 15VDC, should I warn me ? Would the
diode be dead ?
I tried to join temporarily a secondary regulated power supply to
reinforce the + 5VDC so as to be sure that the problem did not
come from the logical part of the computer which checks these
voltages and triggers the Power Fail status. By coupling this
external regulated power supply, the computer restarts again, thus
it is definitively the power supply (or the comparator
component(s) of the power fail module)
If I removes all the boards (printer, core memory, scanner, disk
controller, etc.), the Power Fail light eventually goes out, I get
again the 5VDC, so the power has become "too weak" to power the
computer when it is fully populated.
Despite the temporary (and dangerous) look of my assembly with
secondary power supply, I could not stop myself and attempt a boot
procedure via the Cold Start button of the machine from the Disk
Pack, and it works! :-)
http://www.zeltrax.com/classiccmp_forum/first_boot.jpg
<http://www.zeltrax.com/classiccmp_forum/first_boot.jpg>
It seems that I still have problems with the magtape, I had errors
trying to read a backup, but it may be simply because I still
cannot get the machine in 800BPI because of the capricious buttons
of the front panel. I also wrote a tape mark via a "WRITE TAPE
MARK AND REWIND" function, the mark seems to be written but does
not do the Rewind, however if I launch a REWIND only function, it
executes the action appropriately. In short, still things to
investigate on this side.
Notes that the Operating system I used to make these tests is a
very limited OS named DIDOS which was distributed by Nixdorf for
his 620 Serie. As the machine is a clone of DG NOVA 2/10, I wonder
if the computer is compatible with programs for the NOVA series of
Data General? So I wonder if the DCC-116 was compatible with the
software for NOVAs?
The other questions I ask myself at this point are the ways to
transfer softwares or bootable OS on this machine? I have no other
disk pack on another system but I have a nine track tape TU81 +
connected to a VAX 4000-605A under OpenVMS 6.2, and I can put this
computer on my network. Do you think there's a way to make a
bootable tape for my NOVA 2 clone with the Pertec 8840A from a VAX
4000 with a TU81+ ?
Well, to continue, I have to repair this PSU, all information is
welcome, schematics would be ideal of course.
Finally, note that I am not a professional electronics technician,
I fixed a lot of machines basic knowledge, intuition, researches,
comparisons and logic, it is effective but full of limitations
too, so forgive me in advance If I do not always understand the
possible answers of electronics in "high engineering" mode ;-)
As a bonus, the V1 of a small video mounted with a few clips
captured during a session of my nocturnal repairs, during the
first boot of the machine since 3 decades ! (on my music, yes, I'm
also a composer ;-) )
https://youtu.be/5jWOUtLKRIU
Thanks a lot to all in advance ;-)
Dominique
--
Thanks,
AJ Palmgren
http://fb.me/SelmaTrainWreck
https://www.facebook.com/profile.php?id=100010931314283
https://www.linkedin.com/in/aj-palmgren-4a085516/
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