With the information about the veclink cables I was given a couple of binaries.
One of the binaries ("vl_test.bin") is a test program for the veclink V1 cable. The program was most likely written by Alex Herbert.
I disassembled the program and commented it.
It is by now a very well documented example on how to use veclink V1.
It can be found in the directory:
codelib/Snippets/Alex Herbert/VecLinkV1/vlink1.asm
The program can be assembled and run in vide.
If you want you can look at it and rip it apart, but keep in mind, that my documentation says that VecLink V2 is much more stable.
For more information look at the source to the example and possibly at the "Emulation: VecLink V1 + V2" section.
Let me remind you, that there is no way to "automatically" configure vide to run two vecx instances, you have to start two instances manually:
Manually meaning:
go to the main menu and start a vecx
select the veclink binary you would like to play
press start
select for port 0 the input device you would like to use
select for port 1 the veclink cable you would like to use, start with the "left" side (although it does not really matter which side is plugged in first)
repeat the above process for a second vecx instance,
for port 1 select the "other side" (right?) of the same veclink cable

VecLink example