Saturday, September 21, 2019

Another version of the DSS620 from Nixdorf & Power Supply

Dominique shared these with me today, saying he found these pictures a long time ago. finds no matches.
To see the power supply current/recent auction, open this post.

Monday, September 9, 2019

Building a Power Supply for a DG Nova / DSS-116 from "scratch"

To keep costs down, I'm going to attempt to start with a modern ATX power supply (and likely 2 or 3 laptop power supplies), and attempt to adapt it/them, simply because I have such a surplus of all of these.

The DG Nova power supply apparently consists of these voltages:

+11v (Front panel lamps only?)
-15v (Optional for customers only?  What does that mean?)
+/-15v Oscilating at 60hz/50hz from the source AC power line input, 30v peak-to-peak
+5V OK   7-8vdc?
PWR FAIL 3-4vdc?
MEM OK   3-4vdc?

Here's some golden information in the 1969 DG Nova Maintence Manual on power signals.
And yet more, somewhat differing information on some/all of the same power supply outputs, in the Technical Manual for the Nova 800 Volume I, page 4-47 (starts at the bottom of 4-46 and goes all the way through 4-50.  Almost all of this seems relevant for creating a power supply from scratch)
The "P2" "lower power supply" connector on this backplane is mapping out as follows:

Well, it ALL depends on how you number the pins on this connector. Are all of the even pins on one side, where all the odd pins are on the other?  Like all of the board backplane connectors? NO.  Turns out that there's inconsistency with the numbering scheme on the backplane.  Some connectors are the all-even side and all-odd side, and others are sequential each side, and then back to the top on the other side where the sequence continues...Talk about confusing!

P2, the main (lower) power connector to the backplane, where the resistor board connects the power supply to the backplane:
01-05 +5v 
06    A9  on Slots 2-12 RINH
07    A11 on Slots 2-12 RINH
08    A15 on Slots 2-12 RINH
09    A13 on Slots 2-12 RINH
10    A19 on Slots 2-12 RINH
11    A24 on Slots 2-12 RINH
12    A28 on Slots 2-12 RINH
13    A25 on Slots 2-12 RINH

14    A27 on Slots 2-12 RINH

15    A29 on Slots 2-12 RINH

16    A23 on Slots 2-12 RINH

17    A21 on Slots 2-12 RINH

18    A17 on Slots 2-12 RINH

19    A18 on Slots 2-12 RINH

20    A7  on Slots 2-12 RINH
21    A5  on Slots 2-12 RINH
22&48 +15v to A10, B46, B84 on Slots 2-12  )
23    POWER FAIL to A5 on Slot 1
24    MEM OK to A9 on Slot 1
25    +/-60Hz AC to B6 on slot 3 
26    Lamp Ground (to P1 pin 40)
27-31 +5v
32-47 Ground
48&22 +15v to A10, B46, B84 on Slots 2-12   
49    -15v "available as a customer option..."
50    +5v OK to A8 on Slot 1 (so is this high or low in an OK state?)
51    -5v unreg. to A6, B81 on Slots 2-9   
52    +15v unreg. LAMP (to P1 pin 33)

There's nothing on the backplane other than a "1" by pin 1, so unless you figure it out through trial and error, you'd never know which way the pins are numbered!  Thus my numbered image above.

From my video below, I mention missing power supply connector "resistor" boards also.

I MAY have found one of those here on bitsavers...
And then, for schematics for these power supplies, first, from my own site right here, I've posted 2 books full of schematics, and here's 12 schematic excerpts that may be relevant  (warning, 11Mb file)

And more continued below.....

Sunday, September 8, 2019

14" Magnetic Plate * Hard Disk Drive Platter Nixdorf Computer * VINTAGE * Rarity

The original eBay title in German is:
14" Magnetplatte • Hard Disk Drive Platter Nixdorf Computer • Vintage • Rarität

So, what does this disk have on it?  Could it be Entrex system OS of information?  What does that handwritten label say, exactly? I see that it is similar to the disk packs that Dominique has on his system, which are taken by the Diablo Model 40 disk drive.

Original eBay Auction                                      eBay Auction Archive
Google Translation:
Uninstall my private computer museum piece by piece .....

Stop by, there are still rarities until the year 1974

They offer a rarity of Nixdorf computer.
It is a 1-fold magnetic disk (platter) with a capacity of about 5 MB.

Condition see pictures

Due to the current case law on product liability and the new provision of the law of obligations in the Civil Code, I am obliged to point out that the item is sold as used to the exclusion of any warranty private by me. Please ask your questions before buying. The item is sold "as is" by Privat. This means: "With the purchase, you expressly agree to waive the statutory warranty and warranty for second-hand goods completely." Please do not buy the item if you disagree with these rules.

private sale
No warranty, no warranty, no return

Insured shipping

Original German:
Löse mein privates Computermuseum Stück für Stück auf.....

Schauen Sie vorbei, es kommen noch Raritäten bis ins Jahr 1974

Sie bieten auf eine Rarität von Nixdorf Computer.
Es ist eine 1-fach Magnetplatte ( Platter ) mit einer Kapazität von ca. 5 MB.

Zustand siehe Bilder

Aufgrund der aktuellen Rechtsprechung zur Produkthaftung und der Neuregelung des Schuldrechts im BGB bin ich gehalten, Sie darauf hinzuweisen, dass der Artikel als gebraucht unter Ausschluss jeglicher Gewährleistung von mir Privat verkauft wird. Bitte stellen Sie Ihre Fragen vor dem Kauf. Der Artikel wird "so wie er ist" von Privat verkauft. Dies bedeutet: "Mit dem Kauf erklären Sie sich ausdrücklich damit einverstanden, auf die Ihnen gesetzlich zustehende Garantie und Gewährleistung bei Gebrauchtwaren völlig zu verzichten." Kaufen Sie den Artikel bitte nicht, wenn Sie mit diesen Regeln nicht einverstanden sind.

Keine Garantie, keine Gewährleistung, keine Rücknahme 

Versicherter Versand

Wednesday, September 4, 2019

Nixdorf Dumb Terminal 1970's and 1979 Nixdorf modem (Bray, Wicklow, Ireland)


My closer photo analysis leads me to believe that this is indeed
which means that the person who posted this ad 3 years ago is likely the one who bought it from Matteo on eBay in 2008-2009 

From seller PSFan
Member since: November 22, 2012
Location:         Baldonnell, Dublin
Sold items  
Active items



I'm selling my beloved Nixdorf Terminal and modem. The terminal came all the way from Italy - Rome to be precise - where it was found in a Barn! I've owned it for 7 years. It cost around €110 alone to ship at the time!

It powers on and the fan kicks up, but the display is garbled. Who knows, it may be a loose connection somewhere or a chip issue. Not bad given it's age and history I guess! It's time to pass this on to someone who can investigate it further. As is, it's a fascinating slice of history being as it is over 40 years old.

The Modem came from the U.S., and was bought around the same time. It was manufactured in 1979. These are unique items that I'm selling reasonably priced as I'd like the space they're taking up. Needless to say, these are for collection, Bray area.

Thanks for looking!

I am hoping that we can find the seller of this, since the ad was withdrawn 3 years ago, but the seller still seems somewhat active.  We will try.  If you are the owner of this terminal, please contact us here!  Thank you!