XE1541 Extended or XM1541 Multitasking Cable Construction


List of Materials:
  • One D-SUB DB25 male connector with housing
  • Four 1N5819 or BAT85 diodes
  • One 6-pin standard circular DIN plug
  • 5 feet six-wire (or more) cable
kit



1.- First we must mechanize the diodes as shown in the next picture, for proper soldering:

diodes

Once mechanized, you will have something like this:

mechanized

If you look at the DB25 connector (front view, looking at the pins), we can see little numbers on each pin as follows:

db25

So from the soldering side, the numbers are like:

db25_solder

Diodes have two pins, called the anode and the cathode.  A cathode is identified with a mark on the diode body.

diode

We start by wiring pins 13 through 25 together, keeping a good solder.  You can use one of the wires cut from the diodes during the mechanizing step:

ground

First diode: Anode to pin 10 and cathode to pin 16:

step2

Second diode: Anode to pin 11 and cathode to pin 17:

step3

Third diode: Anode to pin 12 and cathode to pin 14:

step4

Finally, the fourth diode:  Anode to pin 13 and cathode to pin 1:

step5

A top view of the DB25 connector after all four diodes are solded.  You can have a different soldering option for the fourth diode, like installing it over the pins, which result in a shorter plug to insert in the housing (a picture of this configuration can be seen later, with the picture of the cable with all 5 wires solded):

step6

Connector wiring starts.  Below, you can see the association of colors commonly used by me in the construction of this cable.  I will show you two connection schemas: one for the XE1541 cable and the other one for the XM1541 cable.  Before doing the wiring, you need to decide if you are going to make the XE1541 or the XM1541 cable:

xe1541

xm1541

So I use the following color schemes at the DB25 end:
Wire Color XE1541 XM1541
Blue pin 13 pin 13
Brown pin 12 pin 12
Orange pin 10 pin 11
Light Blue or Green pin 11 pin 10
White with brown stripes pin 18-25 pin 18-25

Here are some pictures of the DB25 connector after the wiring:

xe1541open
XE1541

xm1541open
XM1541 (Here I am using BAT85, which are substitutes for the 1N5819 diodes, shown in the XE1541 above)

We can now close the housing , without damaging the wires.

Next step is to solder the wires in the other end of the cable: the DIN plug.  I use the following coloring scheme:

din
This is the 6-pin DIN plug.  This is the solder side of the plug.

Wire Color PIN
Blue pin 3
Brown pin 4
Orange pin 6 (center)
Light Blue or Green pin 5
White with brown stripes pin 2

And here is the picture of the DIN plug with the wires solded:

din_open

And finally, the cable completely assembled and ready to use:

final

I recommed that you test all connections and wiring before use.  I also recommend powering everything down before connecting / disconnecting the cable.  A good starting point is to use the xctest program to see how the cable is responding.

You can find original schematics and more info about the XCables here.  Any questions, please contact me at nkc_store@yahoo.com

You can also buy the cable already built and ready to use in my amazon store. I use a PCB to build the cables I sell, as you can see in the following pictures:

xcablepcbXA1541

©2010 Vintage Computer Cables from original work by Nicolas Welte, Wolfgang Moser and Michael Klein.  Thanks also to vteramos@yahoo.es.