Yeah at this point pop it open, unlock the heads (the white cam down at
the base there, trip it) and get the heads to move. They should smoothly
move with a bit of effort. Then fire it up and see if anything works.
I'm going to run this one for a bit in the backup pdp11 here, see if it
runs if you fire it up every month or two. Once again what do I have to
lose :-)
I should probably install a TK50 for backups.
C
On 2/3/2023 11:34 PM, Zane Healy wrote:
I’d just like to say that 25 years ago, RD53’s were *EVIL*. I do have one that
I should try taking apart. I failed to back it up the first time I powered it
on. It didn’t boot the second time.
ESDI or SCSI is the way to go, at least that was true 20-25 years ago. Today
I’d be inclined to say SCSI is the way to go.
Zane
On Feb 3, 2023, at 7:48 PM, Chris Zach via cctalk <[email protected]> wrote:
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
