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 <microtechd...@gmail.com
<mailto:microtechd...@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@classiccmp.org <mailto:cctalk@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/
