Probably this schematic:
https://goughlui.com/wp-content/uploads ... rev_d3.png
Says this in the manual:
DC power connector: Standard power connector to supply +5V (rev. B board) or +7 to +9V (rev. C board and later; will internally be transformed to +5V) DC to the board (if desired). Useful when powering a 3.5” drive through the board, as these usually don’t need +12V. The PSU must deliver a minimum of 1A, tip is hot, shield is ground.
I get no 5V on neither connector unless USB is hooked up, position right on the three pin connector (FDD connector to the right).
According to the schematic the middle pin goes to the 5V rail, you can connect the 5V rail directly to the floppy/hdd connectors or via the 5V regulator which is connected only to the external barrel connector.
So... how would (as described in the manual) you be able to power a 3.5" drive - unless connecting all three pins together? (If my Rosalie Rev D is according to the schematic).
My measurements confirm that part of the schematic.
I guess it might be easier to just power the drive directly with it's own PSU...