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...
Wednesday, January 1, 2020
Wednesday, December 18, 2019
Entrex/Nixdorf Terminals Upgraded
https://deskthority.net/viewtopic.php?f=2&t=23215&p=457390#p457390
not related, but still...it's there, I just had to throw it in!
Saturday, November 30, 2019
SEECHECK from REDIFON developed with Entrex
Equivalents: ENTREX 480 from ENTREX, DATENSAMMELSYSTEM 620 from NIXDORF.
https://pl.wikipedia.org/wiki/Rejestrator_danych
The connection comes from this page:
https://www.aldricharchive.co.uk/a-technical-history-of-rocc-computers
https://pl.wikipedia.org/wiki/Rejestrator_danych
The connection comes from this page:
https://www.aldricharchive.co.uk/a-technical-history-of-rocc-computers
Older web version
https://web.archive.org/web/20191103034213/http://www.aldricharchive.com/technical-history-rocc.html
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Seecheck (1972)
The technology for the Seecheck system was developed with the Entrex company in the US, Redifon having the rights to sell it in the UK, and also developed a market in Eastern Europe and the Middle East. It was based around the Nova 16-bit mini computer produced by Data General, and set the basic architecture of all the systems developed down to the 2885 in 1990.
The technology for the Seecheck system was developed with the Entrex company in the US, Redifon having the rights to sell it in the UK, and also developed a market in Eastern Europe and the Middle East. It was based around the Nova 16-bit mini computer produced by Data General, and set the basic architecture of all the systems developed down to the 2885 in 1990.
Seecheck Basic Control Groups (BCG) used a ‘Lowboy’ rack containing a 17 slot ‘DCC’ mini, tape drive, disk drives and necessary power supplies. The DCC mini computer had a 1200ns processor and 64KB of core store, and was also the only Nova based system supplied with programmers switches built in to the front panel, all subsequent systems having a detachable one for engineers’ use only.
One or two 2.5MB or 5MB DRI disc drives were supported, these utilising a single platter removable cartridge (although used as a fixed unit in Redifon systems) with a rack and pinion head actuator mechanism and optical sensor similar in principle to that subsequently used in floppy drives. The tape drive could be either a 7-track 556 bits per inch or a 9-track 800bpi.
Up to 32 Mk II terminals could theoretically be connected, each having its own I/F board in an auxiliary card cage, but eight was the normal limit. The terminals were normally the MK II type with the keyboard built in to the display unit, although the MK I was similar but with the base of the terminal integrated into the desk top. Both versions had a 480 character display. From the MK II onwards all Redifon terminals had a Cyrillic variant.
The Redicheck system was a cut-down version with only 48KB of core and a maximum of eight terminals.
The software was a pure key-to-disc application, although VDU orientated, and very flexible compared to the card or paper tape punching systems it was replacing. This software became known as ‘7’ series.
In 1974 Redifon signed a licensing agreement with Metronex/Meramat in Poland whereby Seecheck would be manufactured in Poland using Soviet-bloc hardware for sale in Soviet-bloc countries. Although peripherals were available in the Soviet-bloc there was not a suitable CPU so Redifon designed and developed a DG Nova compatible mini, called the P.1, for manufacture in Poland. This CPU complied with the then CoCom strategic embargo. Later Redifon would up-grade this design for the E.17 mini made in the UK.
So that would be a clone of a clone of a clone perhaps
And then somehow we get to this image, which shows the newer Entrex keystation "trapezoid" terminal?
So that would be a clone of a clone of a clone perhaps
And then somehow we get to this image, which shows the newer Entrex keystation "trapezoid" terminal?
More on Redifon:
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Metronex is the Polish foreign trade organization which trades in computers, automation equipment, and instruments; its turnover in 1973 was estimated at about $300 million. Computers and peripherals have been exported to all COMECON countries regularly for many years...
...and Redifon of the U.K. licensed MERA to manufacture the Seecheck key-to-disc systems which are· based on an original Entrex design from the U.S.
Sunday, November 24, 2019
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...
A company (not very creatively called) Recognition Equipment...NOT Entrex, but they are certainly using Entrex Data/Scopes there.
club-nixdorf.org archives & The last 620
Does anyone know the original author of this site? Is he/she still out there?
(backup at archive.org/web)
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
http://www.club-nixdorf.org/cn/web/anecdotas/ultimo620.htm
(backup at archive.org/web)
(backup at archive.org/web)
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
(backup at archive.org/web)
Friday, November 1, 2019
Scanner Board/Terminal Multiplexer Board
Clearly this is a very important component of the system, unique to Entrex! According to Barry King, who was an Area Field Engineering Manager for Entrex from 1977-1991 in Nashville, TN:
"The key to the Entrex system was the Scanner board and software developed by 2 or 3 guys at MIT as a project to complete their Master's.". Read more here.
Thursday, October 31, 2019
Hex PerTerm boards - Entrex 480/Nixdorf 620
This board is from Slot 17 of the Heinz Nixdorf MuseumsForum's Nixdorf 620 system on display, in Paderborn, Germany.
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!
https://www.instructables.com/id/Fridge-Magnet-Keyboard/
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!
https://www.instructables.com/id/Fridge-Magnet-Keyboard/
Entrex Data/Scope CRT Replacements - GTE Sylvania 9VADP4
Well, the CRT has indeed "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]
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.
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...)
http://www.vcfed.org/forum/showthread.php?23603-2716-to-2708-conversion&p=165483#post165483
and
http://compgroups.net/comp.os.cpm/question-on-eprom-programmers/945291
vs
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
(which is roughly the opposite of what I wish to do...)
http://www.vcfed.org/forum/showthread.php?23603-2716-to-2708-conversion&p=165483#post165483
and
http://compgroups.net/comp.os.cpm/question-on-eprom-programmers/945291
Entrex Data/Scope turned Commodore C116
On 18/10/2019 09:55, Andreas wrote:
Hello...,
I found your page
-https://entrex480.blogspot.com/p/nixdorf-620-restoration.html-
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.
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