Did 5.25" floppies undergo a change in magnetic coating?Only “Drive A:” detected with two floppy disk...
Pronunciation of powers
Replacement ford fiesta radiator has extra hose
Auto Insert date into Notepad
What are these green text/line displays shown during the livestream of Crew Dragon's approach to dock with the ISS?
How can atoms be electrically neutral when there is a difference in the positions of the charges?
I am on the US no-fly list. What can I do in order to be allowed on flights which go through US airspace?
Is there a low-level alternative to Animate Objects?
What if I store 10TB on azure servers and then keep the vm powered off?
Linear regression when Y is bounded and discrete
Where is this triangular-shaped space station from?
If a druid in Wild Shape swallows a creature whole, then turns back to her normal form, what happens?
How to tighten battery clamp?
What is a term for a function that when called repeatedly, has the same effect as calling once?
Why does Starman/Roadster have radial acceleration?
Do authors have to be politically correct in article-writing?
I can't die. Who am I?
What type of postprocessing gives the effect of people standing out
If nine coins are tossed, what is the probability that the number of heads is even?
Called into a meeting and told we are being made redundant (laid off) and "not to share outside". Can I tell my partner?
What am I? I am in theaters and computer programs
Contradiction with Banach Fixed Point Theorem
"Murder!" The knight said
Is my plan for fixing my water heater leak bad?
Why does the 31P{1H} NMR spectrum of cis-[Mo(CO)2(dppe)2] show two signals?
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 9 hours ago
rwallacerwallace
9,390446137
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 9 hours ago
rwallacerwallace
9,390446137
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 9 hours ago
rwallacerwallace
9,390446137
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 9 hours ago
rwallacerwallace
9,390446137
asked 9 hours ago
rwallacerwallace
9,390446137
asked 9 hours ago
rwallacerwallace
9,390446137
asked 9 hours ago
rwallacerwallace
9,390446137
asked 9 hours ago
rwallacerwallace
9,390446137
9,390446137
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
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 7 hours ago
tofrotofro
15.7k33190
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "648"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fretrocomputing.stackexchange.com%2fquestions%2f9300%2fdid-5-25-floppies-undergo-a-change-in-magnetic-coating%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
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 7 hours ago
tofrotofro
15.7k33190
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
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 7 hours ago
tofrotofro
15.7k33190
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
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 7 hours ago
tofrotofro
15.7k33190
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 7 hours ago
tofrotofro
15.7k33190
edited 6 hours ago
answered 7 hours ago
tofrotofro
15.7k33190
answered 7 hours ago
tofrotofro
15.7k33190
answered 7 hours ago
tofrotofro
15.7k33190
15.7k33190
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
add a comment |
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
Do you have any idea why the difference in 3.5" was smaller? Is it because DD had already a higher than needed coercivity (by the way, you have a typo there) from the beginning? Does that also mean that they could have produced DD-compatible drives with higher capacity instead of introducing a slightly different coating?
– Selcuk
1 hour ago
add a comment |
Thanks for contributing an answer to Retrocomputing Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fretrocomputing.stackexchange.com%2fquestions%2f9300%2fdid-5-25-floppies-undergo-a-change-in-magnetic-coating%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
