This is probably a long shot here but…! I’m either trying to source one of these cables or build one. Basically it allows the software to control the TBC’s levels. On the A4000 you need the cable to connect to the external DB-25 port. In the A2000 you can use a three wire connector to connect to the internal serial pins on the MB.
So either a source for one of these (someone here?) or a little explanation of the included diagram. I can build one from the schematic and it’s a no brainer for pins 2,3 and 7 from the DB-25 to pins 6, 2 and ground (shell) on the DIN-9. I even have cables here I can hack. But what of the additional Pinots shown? At first I thought they were just looped to ground but now it seems they may be a seperate connection to another piece of equipment?? Not too likely since an internal connection would just be 3 wires. But the schematic shows an interesting Pinot to a GPI trigger. Not so sure how to make this now. Anyone??