Can't read A drive

  • Thread starter Thread starter Helixal
  • Start date Start date
H

Helixal

I just installed Windows xp sp3 on an older Compaq workstation. When I try
to read a file on the A drive I can get the list of files on the floppy but
I cant read any of the files even .txt files. I get messages like "cannot
read theA:readme.txt file or in another case "the folder is invalid or
corrupted" I can use notepad to write a file and then write it to the
floppy and I can read the file back My objective in all this is to load
windows 3.1 into the virtual machine Sun virtual Box. When I try to load
the boot disk using virtual box I have the same problem.
 
I think the key here is OLDER workstation, try replacing the floppy drive,
it's possible that either the drive is out of alignment and not finding the
proper bits to locate the file(s), and or the floppy discs have gotten
corrupted, since new floppy drives are really cheap, just get a new one.
 
Helixal said:
I just installed Windows xp sp3 on an older Compaq workstation. When I try
to read a file on the A drive I can get the list of files on the floppy but
I cant read any of the files even .txt files. I get messages like "cannot
read theA:readme.txt file or in another case "the folder is invalid or
corrupted" I can use notepad to write a file and then write it to the
floppy and I can read the file back My objective in all this is to load
windows 3.1 into the virtual machine Sun virtual Box. When I try to load
the boot disk using virtual box I have the same problem.
Click to expand...

Did you use a cleaner diskette (the wet type) to clean the heads? Although
the floppy drive has a spring-loaded coverplate to hide the slot, the vacuum
from the case fans pushing air out the back of the case will draw air past
the floppy's coverplate. The result is you get dust inside your floppy
unless the intake path elsewhere (front cover, side panel) are so
unrestricted that all the intake airflow comes through them.

Did you format the floppy in the diskette drive that is in this old Compaq
host or on some other host? If not, the alignment for tracks in the
diskette drive in one host might be sufficiently different than the
alignment for the diskette drive in the old host.

You sure the diskette drive types are compatible? You might have formatted
the floppy in a 2.88MB 3-1/2" ED diskette drive but perhaps the old Compaq
host only has a 1.44MB 3-1/2" HD diskette drive. Also, is HD or ED printed
on the floppy itself? See http://en.wikipedia.org/wiki/Floppy_disk.

Floppies are known to lose bits over time (i.e., they lose retentivity due
to magnetic dipole stress - they want to realign over time to reduce stress
from differing polarities and this "softens" the recorded data), especially
because of the physical contact of the heads scraping against the flexible
media. Have you ever refreshed that floppy to ensure to realign the dipoles
to strengthen detection of the bits read from that floppy? When was the
last time you wrote to the floppy? How long have the files been sitting on
that floppy without ever getting rewritten (not read but rewritten)?
Floppies are supposed to have up to a few years of data retention but the
data often starts going "soft" before that which generates read errors
unless the data on the floppy gets refreshed (by getting rewritten).
Because there is no shielding inside the soft shell for a floppy, they are
also susceptible to stray magnetic fields, like from a magnet or old
mechanical telephone bell ringers, which can soften the magnetic recording
(even sufficiently to make the sectors unreadable). There are utilities,
like SpinRite with its Level 3 refresh function, that will rewrite all
sectors of the magnetic media to realign the dipoles to strengthen the
signal and detection of the data on the floppy or disk. You'll need to
decide if the value of the data on the floppy is worth the cost of getting
SpinRite to refresh that floppy or attempt to recover unreadable data.
 
VanguardLH said:
Did you use a cleaner diskette (the wet type) to clean the heads?
Although
the floppy drive has a spring-loaded coverplate to hide the slot, the
vacuum
from the case fans pushing air out the back of the case will draw air past
the floppy's coverplate. The result is you get dust inside your floppy
unless the intake path elsewhere (front cover, side panel) are so
unrestricted that all the intake airflow comes through them.

Did you format the floppy in the diskette drive that is in this old Compaq
host or on some other host? If not, the alignment for tracks in the
diskette drive in one host might be sufficiently different than the
alignment for the diskette drive in the old host.

You sure the diskette drive types are compatible? You might have
formatted
the floppy in a 2.88MB 3-1/2" ED diskette drive but perhaps the old Compaq
host only has a 1.44MB 3-1/2" HD diskette drive. Also, is HD or ED
printed
on the floppy itself? See http://en.wikipedia.org/wiki/Floppy_disk.

Floppies are known to lose bits over time (i.e., they lose retentivity due
to magnetic dipole stress - they want to realign over time to reduce
stress
from differing polarities and this "softens" the recorded data),
especially
because of the physical contact of the heads scraping against the flexible
media. Have you ever refreshed that floppy to ensure to realign the
dipoles
to strengthen detection of the bits read from that floppy? When was the
last time you wrote to the floppy? How long have the files been sitting
on
that floppy without ever getting rewritten (not read but rewritten)?
Floppies are supposed to have up to a few years of data retention but the
data often starts going "soft" before that which generates read errors
unless the data on the floppy gets refreshed (by getting rewritten).
Click to expand...

Vanguard, do you know of any cite that talks about this floppy data
retention issue? It would be an interesting read.
 
Bill said:
Vanguard, do you know of any cite that talks about this floppy data
retention issue? It would be an interesting read.
Click to expand...

Basically I came across the information and issue when I had hard disks that
were increasingly errored with read errors. When I started using SpinRite,
and when, as I recall, there was more technical details available, I
realized just what was dipole stress (my layman's term for why there is a
natural tendency for magnetic dipoles to realign, or I adopted the term long
ago after reading something about it) and why retention wanes with any
magnetically encoded data. I'm sure there are articles out there that
discuss more in depth regarding the physics involved. Just imagine you have
2 bar magnets. When they are oppositely oriented, they tend to push on each
other. When attracted, they pull. There is a natural tendency to realign.
Magnetic dipoles is the due to the moment of the electron. Electrons move
(or their cloud changes). Material is elastic. It moves. Reversed
oriented dipoles don't want to stay that way. Their magnetic force wants to
have them realign.

http://en.wikipedia.org/wiki/Dipole
 
It could be that your floppy drive has sat so long the head mechanism is
sticky and not tracking properly. When I have this issue I just take an
empty or expendable diskette and then format it several times. Do not
use Quick Format as that only deletes the directory area. You want the
system to run the heads back and forth over the entire head travel area.
If the drive doesn't want to reformat the disk because it's already
formatted, just get a magnet and stroke the surface of the disk case.
This will scramble any signatures on the disk and then the system will
reformat it. Just remember the idea is to drive the heads back and forth
over the full range of travel.
 
Back
Top