Seeking To Preserve Entrex 180, 280, 380, 480, 580 & Nixdorf 620 Systems & Data/Scope Keystation Terminals

Friday, June 5, 2020

Nixdorf CEAG Dominit 820 Power Supply

This power supply bears a resemblance to the Nixdorf 620 power supply shown here, but is likely for a different system...possibly Nixdorf's 820?  Seems logical, given that the power supply numbers match the Nixdorf-assigned system numbers.  I'm just archiving it here for reference...
eBay Auction                                        Auction Archive


Sunday, November 3, 2019

Recognition Equipment's Input 80 OCR

Computerworld - May 9, 1973 - page 9-10
A company (not very creatively called) Recognition Equipment...NOT Entrex, but they are certainly using Entrex Data/Scopes there.
But it looks like Recognition Equipment put a sticker over the "Entrex Data/Scope" on the plexiglass screen cover...

club-nixdorf.org archives & The last 620

Does anyone know the original author of this site?  Is he/she still out there?

José A. Margolles Rodríguez  or José Mesa

There are some fantastic promotional images of the Nixdorf 620 (Entrex 480) system and Data/Scope Keystations (terminals) on here...

Where did he get these?

And then there's 
The Last 620


Tuesday, October 29, 2019

Entrex Data/Scope Key Tronic 065-01380 PCB-002D Keyboard preserved as refrigerator magnets!

My friend Cprossu has found this instructables.com post for me.

I left a comment for the author, complimenting him on saving this keyboard from the trash, and being so creative with it.  It is [mostly] preserved, even though the reed switches are now removed completely.  But one of the reasons I like this system is because of the terminals, and the keyboards are always one of the best parts of that!


Entrex Data/Scope CRT Replacements - GTE Sylvania 9VADP4

Well, the CRT has "gone to air", with the back neck seal broken off...

Monday, October 28, 2019

The MM5240: Understanding the operation of the Entrex/Nixdorf Data/Scope Keystation

The best description I've come across for how these terminals work:

RaymondHng   [Reformatted by me for ease of understanding]

This is not a dumb terminal. It is dumber than a dumb terminal. It is a data entry key station as part of a key-to-disk system. 

I use to work on a competing product, the UNIVAC 1900 CADE (Computer-Assisted Data Entry) system. 

Unlike dumb terminals that have some logic of encoding key strokes into ASCII characters, sending the ASCII characters to the computer, receiving ASCII characters from the computer, storing the ASCII characters in its internal RAM, and displaying the ASCII character on the screen, data entry key stations have no ASCII encoding ability and no internal RAM storage. 

A portion of RAM on the central computer serves as storage for each key station's display. 

Sunday, October 27, 2019

Reading AM2708DC EPROMs on the Scanner Board

On the Nixdorf 620 system owned by the Heinz Nixdorf MuseumsForum in Paderborn, Germany, the Scanner board in slot #5 contains two AM2708DC EPROMs.

Of course, we must read these EPROMs!

According to: https://museo.freaknet.org/en/eprom-2708/

[Translated from Italian to English] To read the EPROM 2708, power it with -5V to the VBB pin (21), +12 V to the VDD pin (19), + 5V to the VCC pin (24) and placing the VSS pin (12) to ground. Then the Not Chip Select pin (20) and the programming pin (18) must be connected to ground. At this point it is sufficient to write the memory address to be read into the indexing bus (A0 ... A9), wait for the output signal to settle (according to the datasheet at most 450 ns) and read in the data bus (Q0… .Q7) the data read.

Everybody else talks about using 2716s in systems that are designed to use 2708s, which is in essence the opposite of what I want to do right now, yet still different.  I just want to accurately and safely read a 2708.

Could it be as simple as building a chip socket adapter, and applying constant +5v, -5v and +12v to the pins 24, 21 and 19 respectively, then setting the MiniPro TL866 to read an AM2716 chip, and click go?

Maybe I should lift/isolate pin 18 as well, so programming can't accidentally happen?

Also reference http://www.jrtwine.com/jtwine/arcade/EPROMRef.htm
Other threads about using 2716s in systems designed for 2708s:
(which is roughly the opposite of what I wish to do...)




Entrex Data/Scope turned Commodore C116

On 18/10/2019 09:55, Andreas wrote:

I found your page

with the help of Philipp Maier. -www.diskettenschlitz.de-  in my
collection I've an old 620 Terminal. In the 1980 I used this monitor
with an enbedded commodore c116. I through out the keyboard and build
in the commodore. Now I tried to restore this system, but the terminal
has a problem with the vertical distraction. Do you have the wiring
diagram for the Terminal?

If your are interested I'll send you some photos.

Best regards

Andreas Stamer
Wolfenbüttel, Lower Saxony

Entrex Datascope PS Serial # 325625
UPDATE 2019-10-27:  After having a lovely conversation with Andreas over Skype, I was able to confirm that, alas, decades ago he did indeed discard the terminal motherboard and keyboard from this Entrex Data/Scope - Nixdorf terminal.  As we can see in the first picture, he replaced both, in a VERY creative fashion, with the full Commodore C116 computer.  But I'm glad to know that he has at least preserved the items shown above.

Andreas also provided a picture of the box of Nixdorf floppy disks below, and even though I haven't been able to receive full confirmation, I believe that he included these only because they are branded "Nixdorf", and not because they had any connection with the original Entrex 480/Nixdorf 620 system, or any components thereof.

Monday, October 14, 2019

diskettenschlitz.de & runningserver.com Entrex / Nixdorf Data Scope Terminal

[Translated from German to English] This is one of the legendary Nixdorf terminals for Nixdorf mainframes. The terminal dates back to the time when Nixdorf was still an independent company. It has a 9-inch black and white picture tube which is covered with a yellow color filter and a thin wire mesh. This is a terminal from the 70s where computers were still huge expensive machines. The purpose of such terminals was to bring the computing power of the mainframe computer to the user's desktop. The terminal thus served as a remote control for the mainframe computer. Today, where personal computers have become small and cheap, the terminal mainframe concept has gone out of fashion. Central mainframe (nowadays, rather, the term "server") 

Unfortunately, this terminal is a wreck, on the one hand, the electronics are incompatible with today's Linux / Unix servers and probably have problems with the memory, as it outputs only a par confused characters. On the other hand, the chassis of the monitor is heavily rusted and the electronics of the monitor is no longer working properly.During the last test I noticed that the picture tube at the back glows blue. A sure sign that it has drawn air.  Since the whole thing is in the bucket, I will I think about what I will do. You could equip the keyboard with a microcontroller and replace the monitor with something new.


This image appears at the bottom of this page on runningserver.com

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.  image.google.com 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 ? Rarit?t

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:
L?se mein privates Computermuseum Stück für Stück auf.....

Schauen Sie vorbei, es kommen noch Rarit?ten bis ins Jahr 1974

Sie bieten auf eine Rarit?t von Nixdorf Computer.
Es ist eine 1-fach Magnetplatte ( Platter ) mit einer Kapazit?t 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 Gew?hrleistung 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 erkl?ren Sie sich ausdrücklich damit einverstanden, auf die Ihnen gesetzlich zustehende Garantie und Gew?hrleistung bei Gebrauchtwaren v?llig zu verzichten." Kaufen Sie den Artikel bitte nicht, wenn Sie mit diesen Regeln nicht einverstanden sind.

Keine Garantie, keine Gew?hrleistung, keine Rücknahme 

Versicherter Versand
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