RX50 checkouts, different firmware?

[Chris Zach]

I've been working through my old RX50 drives figuring out what works, 
what needs cleaning, and what destroys disks.

Using some scratch floppies I have found a couple of them were dirty, 
one had a head with something embedded (that I managed to get out), and 
one RX50 drive totally flunks the diagnostics on my Pro/380 (but does 
sort of work on the Rainbow).

However I have noticed something: As part of my tests I am creating two 
floppies with two 350 block files on them. At first I was testing each 
floppy by writing the files, then doing a diff to compare them with the 
disk. Then I realized I can just have one floppy read and another write 
at the same time with a copy dz1:(file) dz2: and doing a diff both ways.

Two of the RX50's do the Diff silently and quickly. The third however 
clicks the head pad load each track, each disk. I was wondering if this 
is because of firmware differences. When I do a compare to disk there is 
one smooth read from the floppy, but when going from floppy to floppy it 
seems to want to do the head pad each time it switches floppy disks.

Thoughts? Good news is after cleaning and testing I have three RX50's 
which can read from each other, write the disks, and don't leave any 
track marks in the disk oxide. Now I can do a bit of reading of some old 
disks and go from there...

Chris