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Did 5.25" floppies undergo a change in magnetic coating?
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Did 5.25" floppies undergo a change in magnetic coating?
Only “Drive A:” detected with two floppy disk drivesUsing a 360k (DD 5.25") floppy with Windows XP?Was there a special drive, that saved much more than 1.44MB on an HD floppy disk?Formatting a 720K floppy disk over USB fails with Windows 10Availability of 5.25" floppy emulators?Why did common floppies never advance past 1.4 MB in size?Did personal computers ever support 8" floppies?Why did 3.5" floppies win?Why not constant linear velocity floppies?Wanted: 5.25 floppy to usb adapter
3.5" floppy disks, in the transition from 720K to 1.44M, changed the actual coating to a different compound that was magnetically 'stiffer'. This was necessary to support the higher density, but meant the old disks could not support the new high-density format even if used in a new drive. A more subtle and much nastier problem: if you formatted a new disk in an old drive, everything would seem fine, but the information would not have been recorded strongly enough, and might fade over the next few days.
5.25" floppies made several format transitions that together accomplished an order of magnitude capacity increase until the final 1.2M format. Did any of these transitions involve a similar change in the actual coating? Or did the disks themselves stay interchangeable apart from issues of hard versus soft sectors?
history hardware floppy-disk
asked 2 hours ago
rwallacerwallace
9,355446137
add a comment |
3.5" floppy disks, in the transition from 720K to 1.44M, changed the actual coating to a different compound that was magnetically 'stiffer'. This was necessary to support the higher density, but meant the old disks could not support the new high-density format even if used in a new drive. A more subtle and much nastier problem: if you formatted a new disk in an old drive, everything would seem fine, but the information would not have been recorded strongly enough, and might fade over the next few days.
5.25" floppies made several format transitions that together accomplished an order of magnitude capacity increase until the final 1.2M format. Did any of these transitions involve a similar change in the actual coating? Or did the disks themselves stay interchangeable apart from issues of hard versus soft sectors?
history hardware floppy-disk
asked 2 hours ago
rwallacerwallace
9,355446137
add a comment |
3.5" floppy disks, in the transition from 720K to 1.44M, changed the actual coating to a different compound that was magnetically 'stiffer'. This was necessary to support the higher density, but meant the old disks could not support the new high-density format even if used in a new drive. A more subtle and much nastier problem: if you formatted a new disk in an old drive, everything would seem fine, but the information would not have been recorded strongly enough, and might fade over the next few days.
5.25" floppies made several format transitions that together accomplished an order of magnitude capacity increase until the final 1.2M format. Did any of these transitions involve a similar change in the actual coating? Or did the disks themselves stay interchangeable apart from issues of hard versus soft sectors?
history hardware floppy-disk
asked 2 hours ago
rwallacerwallace
9,355446137
3.5" floppy disks, in the transition from 720K to 1.44M, changed the actual coating to a different compound that was magnetically 'stiffer'. This was necessary to support the higher density, but meant the old disks could not support the new high-density format even if used in a new drive. A more subtle and much nastier problem: if you formatted a new disk in an old drive, everything would seem fine, but the information would not have been recorded strongly enough, and might fade over the next few days.
5.25" floppies made several format transitions that together accomplished an order of magnitude capacity increase until the final 1.2M format. Did any of these transitions involve a similar change in the actual coating? Or did the disks themselves stay interchangeable apart from issues of hard versus soft sectors?
history hardware floppy-disk
history hardware floppy-disk
asked 2 hours ago
rwallacerwallace
9,355446137
asked 2 hours ago
rwallacerwallace
9,355446137
asked 2 hours ago
rwallacerwallace
9,355446137
asked 2 hours ago
rwallacerwallace
9,355446137
asked 2 hours ago
rwallacerwallace
9,355446137
9,355446137
add a comment |
add a comment |
1 Answer
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The main technical parameter for a floppy disk's coating is its coercitiviy, i.e. the resistance of ferromagnetic matter to withstand demagnetization. Coercitivity is measured in Oersted, after Hans Christian Ørsted, a Danish physicist who discovered the magnetic impact of electrical current.
- 5 1/4" disks storing 360K and 720K (SD and DD) used a coating with a coercitivity of 300 Oersted.
- 5 1/4 disks storing 1.2M used a coating with a coercitivity of 600 Oersted.
So yes, the coating was changed to support the HD format.
The difference between 5 1/4" DD and HD coating is much larger than the same difference between 3 1/2" DD and HD media - which is 660 Oe an 720 Oe, respectively.
answered 50 mins ago
tofrotofro
15.6k33189
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The main technical parameter for a floppy disk's coating is its coercitiviy, i.e. the resistance of ferromagnetic matter to withstand demagnetization. Coercitivity is measured in Oersted, after Hans Christian Ørsted, a Danish physicist who discovered the magnetic impact of electrical current.
- 5 1/4" disks storing 360K and 720K (SD and DD) used a coating with a coercitivity of 300 Oersted.
- 5 1/4 disks storing 1.2M used a coating with a coercitivity of 600 Oersted.
So yes, the coating was changed to support the HD format.
The difference between 5 1/4" DD and HD coating is much larger than the same difference between 3 1/2" DD and HD media - which is 660 Oe an 720 Oe, respectively.
answered 50 mins ago
tofrotofro
15.6k33189
add a comment |
The main technical parameter for a floppy disk's coating is its coercitiviy, i.e. the resistance of ferromagnetic matter to withstand demagnetization. Coercitivity is measured in Oersted, after Hans Christian Ørsted, a Danish physicist who discovered the magnetic impact of electrical current.
- 5 1/4" disks storing 360K and 720K (SD and DD) used a coating with a coercitivity of 300 Oersted.
- 5 1/4 disks storing 1.2M used a coating with a coercitivity of 600 Oersted.
So yes, the coating was changed to support the HD format.
The difference between 5 1/4" DD and HD coating is much larger than the same difference between 3 1/2" DD and HD media - which is 660 Oe an 720 Oe, respectively.
answered 50 mins ago
tofrotofro
15.6k33189
add a comment |
The main technical parameter for a floppy disk's coating is its coercitiviy, i.e. the resistance of ferromagnetic matter to withstand demagnetization. Coercitivity is measured in Oersted, after Hans Christian Ørsted, a Danish physicist who discovered the magnetic impact of electrical current.
- 5 1/4" disks storing 360K and 720K (SD and DD) used a coating with a coercitivity of 300 Oersted.
- 5 1/4 disks storing 1.2M used a coating with a coercitivity of 600 Oersted.
So yes, the coating was changed to support the HD format.
The difference between 5 1/4" DD and HD coating is much larger than the same difference between 3 1/2" DD and HD media - which is 660 Oe an 720 Oe, respectively.
answered 50 mins ago
tofrotofro
15.6k33189
The main technical parameter for a floppy disk's coating is its coercitiviy, i.e. the resistance of ferromagnetic matter to withstand demagnetization. Coercitivity is measured in Oersted, after Hans Christian Ørsted, a Danish physicist who discovered the magnetic impact of electrical current.
- 5 1/4" disks storing 360K and 720K (SD and DD) used a coating with a coercitivity of 300 Oersted.
- 5 1/4 disks storing 1.2M used a coating with a coercitivity of 600 Oersted.
So yes, the coating was changed to support the HD format.
The difference between 5 1/4" DD and HD coating is much larger than the same difference between 3 1/2" DD and HD media - which is 660 Oe an 720 Oe, respectively.
answered 50 mins ago
tofrotofro
15.6k33189
edited 10 mins ago
answered 50 mins ago
tofrotofro
15.6k33189
answered 50 mins ago
tofrotofro
15.6k33189
answered 50 mins ago
tofrotofro
15.6k33189
15.6k33189
add a comment |
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