how Disk Management scans/registers Drives?

friends this relates to a challenging 'dead' drive I'm needing data from.
I've worked on many before and as you know most of the time you can force a drive to spinup and cough up at least sOME data.... every now and then I get a harder case.

dealing with this caused a question in my mind:
I have the bad drive [PATA notebook drive -seagate momentus] attached to a usb bridge device that I use for all such issues. in this case, when I do a fresh start, with the external bridge powered up before cold boot, once 7 Ultimate gets coherent I run disk Management - the scan will popup the box saying "this disk needs to be initialized" and I give it the go - it gives "device not ready". that does not surprise me since the drive seems to only spin [motor runs] sporadically.
What I'd like to know is: what is the applet "seeing" - what is it in disk management that recognizes there is something akin to a Disk out there on one of the device ports?

the followon question would then be: what low-level tool can I use that can attempt communication with the drive's firmware to try to get a spinup command or something to give me a chance???

I have seen an old macintosh drive - WD if I recall - that was in similar state. sometimes I could get a read via the usb bridge, but no data. finally after days of trying I gradually was able to start reading - it would spin very slowly and erratically, taking literally days to complete the forensic tool's scan....