Getting 360K 5.25 floppy Panasonic JU-455-7 working on an AMPRO LittleBoard

[Ragnarock]

I'm trying to get a Panasonic JU-455-7 5.25 floppy drive to work on an AMPRO Z80 Littleboard.

The Littleboard works with both DS and SS drives, so minimal unknowns here.

The JU455 works as a single sided drive but not as double sided.
I've got 2 of them and they act the same way, so I don't think it's the drives, I think it's the jumper settings.
I harvested these drives from a piece of test equipment so they might have some weird configuration.

There is not a document online that describes all of the jumpers on the JU455-7.

Does anyone know what these these A, B jumpers do?
Could it be something with how side-select operates?

 

[Chuck(G)]

Is PDF page 2 here any use?

 

[ldkraemer]

For your Ampro Little Board Z80 the last Floppy Drive on the Cable needs the Terminator (installed
or enabled). Here is a Photo of the conductors used in the Floppy Cable. Since everything works
except for Double Sided, I'd start with Pin 32 on the Floppy and chase that signal across the PCB
to see exactly where it goes. There may be a Jumper or something on the PCB that isn't shown
in the Jumper Table Chuck(G) referenced.

Conductor for Pin 2 is SPARE not Connector Clamp (leftover from my TRS-80 Info).


Larry

 

[Gary C]

Assuming your drive uses the same FQL0008 chip as the -4 model, the side select just goes straight into the chip but is pulled up by RP1 so it probably needs it fitting on this drive.