Whilst hating to drag this thread up again I will do anyway because it's about the only thing I can find on the whoooooole internet about the Trigsoft cart (and thread isn't that old).
I used to have one, it was what took me from typing in asm as decimal data in a basic program to writing real machine code and that basically kicked off the Meanteam demos.
It was that base unit cart and then about 10 different odd shaped "modules" that you plugged in the back depending on what you wanted to use it for. Basically it was the forerunner of the Expert cart. There was a fast loader, a monitor, I think a "freezer" and God knows what else (I barely used most of them) and you STILL had to program them all from disk..