Worn 1050 drive belt damaged floppies

[BillC]

This is a warning!

 

I recently started making flux dumps of some floppies for a8preservation.com, 4 original SpartaDOS were damaged in the process, I found the damage was caused when I used a Happy 1050 to identify the release on the floppies before dumping them.

 

The drive belt was loose enough that the floppy would spin up when closing the latch, but the head friction would quickly stop the rotation. Where the rotation stopped the head made visible divots is the magnetic media layer. 

 

Anyone who has a floppy drive where the motor runs non-stop could have the same thing happen, the motor not stopping is caused by the floppy not rotating due to a loose belt.

Edited July 14, 2021 by BillC

[archeocomp]

I have a loose belt (that I have no replacement for) in my 1050 and it boots fine from some floppies. RPM check shows it is exactly set. The belt causes only few floppies to be not bootable/readable and RPM check shows no meaningful value. But it is not head friction that makes the difference. It is the sleeve friction. I can feel that those reluctant floppies are considerably harder to turn inside jacket when I try to by hand (outside of 1050 drive). I experienced no head/floppy damage so far.

[BillC]

1 hour ago, archeocomp said:

I have a loose belt (that I have no replacement for) in my 1050 and it boots fine from some floppies. RPM check shows it is exactly set. The belt causes only few floppies to be not bootable/readable and RPM check shows no meaningful value. But it is not head friction that makes the difference. It is the sleeve friction. I can feel that those reluctant floppies are considerably harder to turn inside jacket when I try to by hand (outside of 1050 drive). I experienced no head/floppy damage so far.

Just thought I would warn people that it can happen, these were 4 original SpartaDOS floppies that were damaged.  a8preservation.com was able to recover the data from 2 of them, I don't have much hope for the other 2 I just submitted flux dumps of. They were SpartaDOS V2.3C and V3.2C which are fairly rare, a8preservation.com has no dumps of either, the later 3.2D release is the most common and is preserved(verified by a duplicate).

Edited July 14, 2021 by BillC

[gilsaluki]

Where can one find new belts for these drives.  My drives are really old.

[_The Doctor__]

a worn belt should not cause damage,

a bad head would cause damage

a dirty head would cause damage

not completely dry disk or head could cause damage

a bio film on the disk would cause damage

a fungus/mold/paper lice etc. on the disk would cause damage...

failing disk media coating could cause damage...

 

a careful and practiced cleaning of the head (if not physically damaged) and of the DISK surface/inner lining and jacket might restore the disk to working condition if the material is just pushed in a pile where the head stopped... if the material is scraped completely from the disk it of course can not be restored. Only a minute amount is still needed if the drive is sensitive enough though. You could still recover them or even use them. I've posted a disk that was nearly see through that was recovered with pictures of the damage and arrows showing the areas involved etc. You might find this stuff using a forum search...

 

a loose belt should only cause rpm fluctuations, our drive use flywheel weight to even the rpm's as well as regulation and tachometer... it should never cause damage to the disk surface or every spin up and spin down would clobber all disks... it could only cause 'damage' when writing to a disk in the sense that the data would end up compressed on a sector... you can write that sector again using a good drive in that event, since the 'damage' would not be physical, it would have been data only damage. No damage would occur from a read operation at all!

Edited July 14, 2021 by _The Doctor__

[+bob1200xl]

Some of my SpartaDOS disks went bad on me. Hundreds of other disk used in my 1050s had no problems. Inspecting the ICD disks showed the oxide completely missing - scraped right off..

 

This was maybe 30 years ago, so it isn't old age disks, just bad media from ICD.

 

XF551s have different heads than 1050s, so they may work better.

 

Bob

[MEtalGuy66]

I'm with Bob. The oxide coating on the disk is what I suspect. 

 

however, it may be relevant to note that FYI, xf551s have direct drive spindles, no belts... 

[BillC]

5 hours ago, MEtalGuy66 said:

I'm with Bob. The oxide coating on the disk is what I suspect. 

 

however, it may be relevant to note that FYI, xf551s have direct drive spindles, no belts... 

Quite a bit of the oxide coating came off the v1.1 floppies that failed first. Even with being able to see through the base layer of a quite a bit of a SpartaDOS v1.1 floppy most of the DATA was captured before the coating separated, there were less than 20 missing/corrupted sectors only 2 of which were in use. I was part of a DOS file which was on other floppies, the other had corruption that had been seen before and they were able to restore it and recover the last file. 

 

I have been incorrectly blaming the Happy 1050, I have had another failure that hasn't been in any drive for >9.5 years until I tried making a flux dump.

Below is an image of the opening of the latest failed floppy, a non-original copy of OS/A+, most of the surface is dull except for a few darker areas where some of the coating has likely rubbed off. Quite a bit of oxide around the center drive hole rubbed off where I was rotating the media to view more of the surface as well.

 

Edited July 18, 2021 by BillC

[_The Doctor__]

If you ever see light / dark spots, discolored splotches or white dots on the disk surface, clean it first.... that's the biofilm (mold, disk binding agent that separated, fungus, lice) etc I was talking about. Buggy eggs are bad... it talk little time to clean it gently first and then your usually okay for archiving after that. That sticky stuff pulls the coating off the disks as that binds contaminants to the head and digs trenches...

Edited July 19, 2021 by _The Doctor__