Tuesday, May 23, 2023

Entrex/Nixdorf "Trapezoid" Terminal theories of operation & Testing

;0x40 INPUT        read from ram expansion card (tbd)
;0x40 OUTPUT       poke at FDC (tbd)
;0x48 INPUT        read the key modifier bits (i assume) from keyboard, and the key pressed latch bit
;0x48 OUTPUT       (unused in ROM) alternate poke at FDC
;0x50 INPUT        read the keyboard state and clear they key ready latch

;0x50 OUTPUT       tough to see from the schematic, seems to toggle an unconnected port, could be a feature we dont have?

;0x58 OUTPUT       write to interface card register high
;0x60 OUTPUT       write to interface card register low

;0x68 INPUT        read from interface card buffer
;0x68 OUTPUT       something to do with transmit (previously predicted this as transmit byte)

;0x70 INPUT        read the interface card "printer status" register
;0x70 OUTPUT       something to do with transmit (tbd)
;0x78 INPUT        read the interface card status register
;0x78 OUTPUT       write status to interface card

Monday, April 17, 2023

Cortron 35-500179 80-350253 Keyboard for the Entrex Trapezoid Terminal

Notice that the build date on the ID tag of this keyboard says 1986, even though that is a full 7-8 years after the build of the rest of the terminal (1978-79).  The IC chip dates all seem to back this up on the keyboard (84-85 dates) and the terminal (78-79 dates) This is curious, but not unheard of.
Since only 5 of these terminals are documented to survive in the world so far, what are the dates of the other 4 keyboards?  We shall find out...because we have 3 of them, and we hope to get dates from the other two!    

Saturday, April 1, 2023

Entrex Software Inc. - In the Days of Knights & Kings ©1989

(my archive on Google Drive)

All of my analysis brings me to the conclusion that this software company (if it is a software company) had NOTHING to do with the Entrex 480 systems that this website is about.  Perhaps by 1989, the trademark on the original Entrex name had expired, and this small software development company took it over, and repackaged some existing games by Softech Microsystems and maybe added some of their own features?

Perhaps enthusiasts in the DOS game genre can speak to this...

There's a LOT of other copyright holders in these files.  For example:

Name:In the Days of Knights & Kings
Publisher:Softech Microsystems

Entrex is only mentioned in 1 file:  KNISM.VOL

Here are excerpts:

For the exclusive use of:' The program disk must have an original
          Entrex label on it.

#Copyright 1989 Entrex Software Inc.

 0 157 25 98 47blow-up
 {copyright 1987, 1988 Entrex Software Inc. **  }
 {design by Michael Byrne  **  }
 {program by Johan Van Imschoot and Steve Hughes  **  }
 {research by Ellen Rose  **  }
 {graphics by Reva Hargreaves  **  }


Wednesday, March 8, 2023

Nixdorf Mini Computer SIEMENS Rare Collectible 16-bit System 480 Front Panel (Brief eBay "flash")

Interesting item from the same seller as this removable front panel:

(while the eBay ID is different, it is the same seller, Dick Dubois, former Entrex engineer)

In one day, the listing was created, then removed, and not yet relisted.  Interesting, since he has another one nearly identical, that has been listed steadily for 3.5 years or more.  What happened to this one?
Original eBay Auction                       eBay Auction Archive

Monday, March 6, 2023

Nixdorf 600/55 "Trapezoid" terminals in use at Brooksville, FL courthouse September 1982

Nixdorf 600/ 55 computer system improved record keeping at the Hernado County Circuit Court, where thousands of pieces of information are processed and stored 

September 20, 1982

The new Nixdorf 600 / 55 computer system has improved record keeping at the courthouse to the point where a person using one of the terminals will be able to locate a document delivered to the building as recently as 15 minutes earlier.

Hernando Times Staff Writer

BROOKSVILLE -- It almost has become passe to marvel at the wonderful things computers can do to make our lives easier.

But perhaps nowhere are the benefits of "computer age" more apparent than in an office like that of the cleark of the Hernando County Circuit Court, where thousands of pieces of information are processed and stored each day.

The clerk's office got its first computer in 1974, but that machine was mainly to produce "hard copy" -- computer printouts that simplified the process of finding any of the many records stored at the courthouse, according to Harold Brown, the circuit court....

We just bought this photo, and the moment we did, the original page disappeared.


Entrex/Nixdorf "Trapezoid" Backplane Maps

Sunday, February 5, 2023

Entrex "Redifon Seecheck" system located on web page from 2003 - scrapped long ago unfortunately

Original page at http://www.lupinek.com/pocitace/redifon/redifon.htm
Translated from Czech:

Many of you can't imagine life without computers, it would be hard for an accountant today to calculate wages without a payroll program, the youth would probably be bored without Doom or Unreal Tournaments. Even the price of regular PCs is getting lower and lower and so these are now commonly available to members of households. 

It wasn't always that simple. The proof is in these photographs of the now scrapped Redifon system, which was used until 1996 to prepare the payroll and cost accounting for the company. The whole thing consisted of about 30 terminals, two tape drives, one hard drive (and a heavy one at that), three high-speed cylinder-head printers, and one central unit (if memory serves, it was run by an 8080 CPU and had 128kB of RAM).
Terminals (or Redifon "Workstation")
External memory drive with an incredible 40MB (very decent for the time)
Control computer with i8080 CPU (Redifon "Server") + tape
High speed printer (speed 800 characters per second - that's a page in 1,5 sec !!! )
That's how it was back then !!!

Original web page said "Last edit was 02.12.2003 10:30"  
My last edit of this "repost" is reported here by blogspot/blogger