HI,
I found this pack in a pile that I collected yesterday. It is a blue colour
(instead of the usual light grey), and has a label detailing expected read
voltages and times for inner and outer tracks on each surface.
Is it some sort of diagnostic disk?
This sounds like the 'amplitude test pack' that's mentioned in at least
one of the manuals. It's ueed, as you suspect, to check the head output
amplitdue.
Remember an RLxx doesn't need an alignment pack (it's an embedded servo
drive, you can align the heads on any pack).
-tony