[CB_HK]

Some of the reading I’ve done states that the black cable is supposed to be an automated way the drive would have an ID assigned to it. I’m not sure how true that is, but it makes sense since the original hard drive made a point of saying that it had to be installed in the bottom slot, supposedly issuing an ID of 1. So if that’s true, it’s an interesting way they did it.

The Indigo and Indigo2 drive bays use "geographic addressing". The drive ID pins are connected to the backplane and wired differently at each slot. The same system is used on every SCSI disk with SCA connectors.

The straps and jumpers in the picture above are to configure the drive for the formatter board (the SCSI interface mounted below). The most important settings are how the drive handles density selection (1M/2M), and the ready/disk change signals. Drive Select is set to 0 with a solder bridge since that is the only floppy drive on the Shugart (34-pin) bus. There is no visible legend for the other jumpers, and I found no docs on this model (FD-235HF-710). But their definitions can be sussed out by following the traces from the jumper pins, particularly to Shugart interface pins 2 and 34.

The manual for a related model (FD-235HF-A529) is here: http://bitsavers.org/pdf/teac/
The straps are arranged differently, but their basic function will be the same.

Thank you! That is an excellent explanation and I very much appreciate knowing how the system works.