More on my econet blues.
I've now got a stable econet running with two Model Bs and two Master 128s. Wahay!
It seems that the network socket boxes I made myself some 25+ years ago were misbehaving. There was no strain relief on the cables, so some of the messing about recently tugged the cables, and introduced a short inside one of them. I guess all the dried out sellotape inside wasn't enough to insulate them any more!
So, one problem down. I've got a working econet between the Beebs. But the lot still goes down as soon as I plug the a5000 into it. Station not listening. Sigh.
Interesingly, with the A5000 powered off, the econet runs fine. If I set *Stations running repeatedly and power up the A5000, I get a valid reply from it, briefly, before it actually starts booting up, but as soon as it does, the econet dies.
I've also tried running netmonitor as I connect the A5000, and it seems that it's throwing all sorts of junk onto the lines. It doesn't look like valid packets, just garbage, enough to crash netmonitor, but it's something to investigate. Since I've now tried multiple econet modules, and the only thing between the module and the econet cabling is L8, I'm going to try bypassing that (the Masters don't have this, so it can't be essential, since they use the same econet modules) and see what happens...
Wish me luck!
Edit: 30th July. I made a little adapter to plug onto the pins on the bottom of the econet module rather than allowing it to mate with the motherboard, bringing out the connections to a DIN, so bypassing L8. Made no difference. Damn.