New subject: [SPAM] RQDX3's: Lessons learned.

4 Feb 2023

Some thoughts on this day of working on MFM drives:

1) MFM drives are just going bad. They were always kind of meh in terms 
of reliability, but I think even since 2019 (the last time I checked 
these drives) things have gotten worse. Drives which were readable and 
good then are now either shot or throwing errors and they have had an 
easy 3+ years in my upstairs room.

2) There are at least two RQDX3 ROM sets. The earlier one does not 
support the RX33 floppy and doesn't give any info during formatting. The 
later version (Version 4) does support the RX33 and is a lot nicer.

3) Seagate drives seem to be pretty good, especially the 20mb ones. They 
have no problems, work well, and are pretty right-sized for an RT11 system.

4) RD53 drives are weird. Their main failure is the drive head 
positioner just gets stuck and needs to be worked loose. Unfortunately 
that requires removing the lid. Fortunately there is a good filter in 
the drive along with an air handler that runs air from inside the drive 
body through the filter, then into the spindle where it is blown over 
the heads. Result is a pretty clean drive on the inside and so far 
opening the lid doesn't seem to be a recipe for instant destruction. Go 
figure.

I may try an RD53 in one of my Pro/380's. It's about time I loaded up 
the final version of P/OS, as I can use the Gotek floppy to load 
everything instead of screwing with the RX50's. Or can I do that and 
switch disks on the fly with a single Gotek... Hm.

5) For anything bigger, it's time to retire the MFM drives. Unlike 
RL02's these things just were not that reliable when new and at this 
point are kind of falling apart. I have not had any trouble with the 
ESDI disks, but it might just be a matter of time. Perhaps I should look 
into duplexing my 330mb CDC drive in the 11/84....

CZ