Nixdorf 620 in a September 1983 Datapro publication

September 1983 Datapro!  Archived by bitsavers in August 2016

http://www.bitsavers.org/pdf/datapro/programmable_terminals/Datapro_C21_Nixdorf.pdf

ANOTHER Entrex Data/Scope (Nixdorf Keystation) for sale in Frankfurt, Germany

Amazingly, within 2 weeks, ANOTHER one shows up on eBay!  €600 asking price this time. We're luck to see one of these on eBay ever, and for two to show up within 2 weeks of each other is simply unheard of...very unusual.
Did the first one cause the second one to be listed within the mysterious forces in the vintage computing universe?  We may never know!

This one has the rare 00 and 000 keys on the number pad.  I believe I saw this on reddit once, presumably in Australia.

Current Auction                                         Auction Archive

Seller warumnichtmalwasneues

Wangco Model 10 - Tape Transport of choice for early Data General & Entrex 480 systems?

HIGHEST Resolution

HIGHEST Resolution

Wangco_Mod_10_Brochure.pdf

P-108_Entrex_System_380_Description.pdf

Entrex Data/Scope (Nixdorf Keystation) for sale in Peine, Germany

Current Auction                                         Auction Archive

Seller emg_regler51

Besides the fact that it is extremely clean, I think the most interesting part of this listing is the original invoice provided for the device in German.  This gives an insight into how Nixdorf was selling these within the German or European market.  Besides that, however, with a price of  €1,000 , I'm just going to have to sit and watch what happens.

UPDATE:  This Sold March 12, 2025 for "best offer" after the price dropped to €700, so does anyone know who bought it?  We hope it goes to a good home, and we see it work again!  Please contact us if you have it!

More MERA 9150 hardware & manual resources found!

By Cordylus

System MERA 9150 Podręcznik Serwisowy Cz. 2

How the Entrex 480 / Nixdorf 620 Boots

Reference decoded tapes verbose files on GitHub Forgotten Machines

March 24, 2024 From Bruce Ray with Wild Hare Computer Systems / NovasAreForever.org:

The standard DG/DCC Data Channel device [DCH] tape/disk bootstrap program consists of only 3 instructions:

375/ 062677   IORST

376/ 0601<xx> NIOS <device code>

377/ 000377   JMP 

This is the program initiated by the PL switch on the 'standard' machines

DCH device controllers are designed to boot from record/sector zero of a tape/disk drive into location 0 onward, and therefore overwrites the JMP . instruction at location 377.  Any standard bootable DG/DCC tape/disk [and I would assume Entrex] successfully uses this model.  If a faithful image of a tape/disk is created and appropriately configured in an emulator, the system should be 'bootable'.  A correct SimH-compatible tape restoration works on all of the very-diverse systems I work with, and likewise for disk images and appropriate disk emulation configuration.

Therefore, if a known "bootable" tape is accurately recovered to SimH-compatible format, the resulting contents should behave exactly like the original hardware if the various parameters are met.    This is the basic approach successfully used over the decades for handling even the 'weirdest' client situation.

Once the controller is started [i.e. NIOS <device>] the controller will transfer words from the device to main memory automatically.  Even if an extreme custom hardware modification were made to the front console's program load logic, the examination of the tape/disk record/sector zero might reveal more information, faster, than trying to grok custom hardware modifications.  Knowing the exact [human] operator procedure to bootstrap the system would reinforce

the decision to attack the problem either bottom-down or bottom-up.  Top-down In this case would be to start with a known good accurate copy of the tape/disk media in question, bottom-up would be dissecting schematics to discern the forest from the trees... 

---------------------------------------------------------------------------------------

We provided Bruce with these two recovered SimH-format 9-track tape files:

Entrex_Nixdorf_620_Save_PRIX_22-01-87.tap

Entrex_Nixdorf_620_Master_Didos_1_genere_08-10-83.tap

to which Bruce replied with these glorious preliminary results:

Mera 7951 OM Terminal listed on eBay in Buk, Poland

I've never seen one of these come up for sale on ebay, and yet, since March 2024, it has been listed, on and off.  

It is now March 14, 2025, so it has been listed for one year without being sold.  

2,100.00 PLN ~= $550 USD as of now

Current Auction                                         Auction Archive

Seller waavia

Description translated to English:

Rarity

Condition as shown in photos 

Personal collection preferred

Shipping within Poland 70 zł

Original Polish Description:

Rarytas

Stan jak na zdjęciach 

Preferowany odbiór osobisty

Wysyłka na terenie Polska 70 zł

Nine-Track (9-track) 800bpi NRZI Format decoding

I really appreciate the confirmation of 0x13, because the ANSI documentation you shared is "clear as mud" on this topic for me. I don't know how this description translates to 0x13, BUT, I AM seeing 0x13 twice at the end of my tapes, so your real-world description overrides my confusion from this ANSI document.

I had no idea how `1 bits in tracks 2, 3 and 8` translates into binary `00010011`. tracks 2, 3, and 6, maybe if you start counting backwards where Parity is track 1, but not 2, 3 and 8....No matter how I arranged it, I got a totally different value from this.

You know, in typing that last message out, I think I just figured out why that ANSI document was SO confusing to me...they renumbered all of the tracks with their own 1-9 numbering system, starting from one of the tape edges, and never really gave a diagram like this saying how their numbering system "maps" to the real-life track names. I guess for ANSI documents, they need to add this additional layer of obfuscation to make their attorneys happy? Anyway, I think I'm getting it through my thick head now.  If I take their diagram and re-draw it like this:

Yeah, I see it now...from left to right

00010011  - 0x13 "TapeMark"
01234567P - real world tracks
765391824 - ANSI track order

OK, 3, 8 & 2, or 2,3 & 8... got it now! Anyway, the main point of my message was to say "Thank YOU" on this, and I know I went a bit overboard.

I really should put these last 2 messages into one of my blog posts. It could help the next less-technical person like myself who dares enter this territory...

-------------------------------------------------------------------------------

SimH .tap files:

larsbrinkhoff — March 14, 2024 at 2:50 AM

Your entire .tap should look like this:

17 of these: "FC 0F 00 00" <4092 bytes> "FC 0F 00 00"

(FC 0F 00 00 is little endian for 0xFFc which is 4092 in decimal)

1065 of these: "3C 0F 00 00" <3900 bytes> "3C 0F 00 00"

End of tape: "00 00 00 00  00 00 00 00"

-------------------------------------------------------------------------------

Link to my Lotus Notes database program decoding this:

Pertec 9-track Formatter "Key To Tape" device

This device is NOT part of the Entrex 480 system, 

but in order to understand a "Key-To-Disk" system like the Entrex 480, 

here is a "Key-To-Tape" stand-alone device to illustrate the differences.  

Notice the "029" keyboard layout?

Acquired from Orrill's Auctions, Los Angeles on March 12, 2024

IBM 029 Keypunch Keyboard vs Entrex Data/Scope

Compare this keyboard to the "029" keyboard option for the Entrex Data/Scopes (Keystations).  As the Entrex 480 advertisements state, this keyboard layout was a featured option on the Entrex Keystations so that operators who were used to the IBM 029 keypunch keyboard layout were able to transition to using the Entrex Data/Scope without any re-training on the keyboard layout.  How cool was that?!

Entrex 480 / Nixdordf 620 System Operation Exploration (a list of screen menu options)

 Recorded near Brussels Belgium November 2021:

See Full Playlist

And THIS is the tape that booted this system!

Original Early 1970s USA Entrex 480 Chassis Card Slots

 This chassis was from the July 2020 Frenchtown, NJ Auction

Digital Commputer Controls

Model No. D-116B

Serial No. 0293

Mera Christmass...

2023 Mera Xmas!

2022

So well done...
from MHKI's Facebook Post

Mera Christmas!

Snake from IKEA

Alan Warren's "in-desk" Entrex Data/Scope with DEC VT-05 and PDP-11 home setup

https://www.facebook.com/groups/40651613978/permalink/10161269378003979

posted by Alan Warren

https://www.facebook.com/groups/40651613978/user/1748734285

It should be noted that the PDP-11 is mounted into an Entrex 480/Nixdorf 620 Rack Chassis, so this is a "PDP Retrofit" into an Entrex 480 system chassis!

Too bad that all of this was scrapped many decades ago...but we thank Alan for the vintage picture!!!