Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: mikeymike on November 01, 2011, 02:19:11 PM
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This question just occurred to me, and I'm just asking to challenge my opinion on this topic - it's been a long time since I did much with floppy disks, but I always had the feeling that HD floppy disks didn't seem to last very long when used in Amiga (DD) floppy drives. Is this a complete load of rubbish?
Of course I understand that the full capacity of a HD floppy disk can't be used in a DD drive, my question is just about reliability/longevity.
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Actually not.
While the same coating was used for the longest period of DD floppy production, there's a problem with the way of writing. Once a disk has been written to just a single time with a HD drive (e.g. factory formatting) the 'harder' magnetic imprint cannot be completely wiped out by a 'softer' DD head. (This is valid for DD disks used in HD drives, too!) Over time, the HD bits can creep back, wiping out the newer but softer DD bits.
So, for longevity - as most Amiga disks tend to be used - it's not advisable to use HD disks. One way to get around this is to use a HD drive even for DD media - but don't mix them with multiple drives. Probably the best way to store important data is on harddisk and backup to quality CD/DVD.
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Also look up "coercivity." There are a metric shyte tonne of discussions around dar Interwebs about this topic as they crop up from time-to-time in various "retro" forums like ours. Interesting stuff out there once you start digging.
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In theory, yes, they may not last as long.
In practice, I've never had any issues with it, both back in the day, when I used floppies for everything, and nowadays, when I just use them for games.
I guess I'd be hesitant keeping very vital data, but even if you do use your amiga for anything important, odds are you have a hard drive and can take multiple backups anyway.
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HD floppy disks didn't seem to last very long when used in Amiga (DD) floppy drives. Is this a complete load of rubbish?
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it's a complete load of rubbish
hd floppies can last as long as dd floppies
in fact there are not technical differences between them ..only a hole
to store the floppies of course a sealed box away from moisture
otherwise they can get fungus like cd and dvds
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This question just occurred to me, and I'm just asking to challenge my opinion on this topic - it's been a long time since I did much with floppy disks, but I always had the feeling that HD floppy disks didn't seem to last very long when used in Amiga (DD) floppy drives. Is this a complete load of rubbish?
Of course I understand that the full capacity of a HD floppy disk can't be used in a DD drive, my question is just about reliability/longevity.
I always found pre-formatted 1.44MB disks would frequently failed to format right away on track 0. What I would do is DMS a disk image to it. After that it would reformat just fine. I have no idea about the longevity.
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it's a complete load of rubbish
hd floppies can last as long as dd floppies
in fact there are not technical differences between them ..only a hole
to store the floppies of course a sealed box away from moisture
otherwise they can get fungus like cd and dvds
They are very different technically. Lots of stuff here:
http://www.retrotechnology.com/herbs_stuff/guzis.html
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it's a complete load of rubbish
hd floppies can last as long as dd floppies
in fact there are not technical differences between them ..only a hole
to store the floppies of course a sealed box away from moisture
otherwise they can get fungus like cd and dvds
Longevity-wise, no, there's little to no difference, except that today the quality as a whole is quite a bit less in the manufacture due to their reduced popularity and sales. For instance, old micro-disks had a dust jacket through the entire internal surface, whereas now there's just a single patch -- arguably this is less effective than the full jacket.
However, there are technical differences between the two.
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Actually not.
While the same coating was used for the longest period of DD floppy production, there's a problem with the way of writing. Once a disk has been written to just a single time with a HD drive (e.g. factory formatting) the 'harder' magnetic imprint cannot be completely wiped out by a 'softer' DD head. (This is valid for DD disks used in HD drives, too!) Over time, the HD bits can creep back, wiping out the newer but softer DD bits.
So, for longevity - as most Amiga disks tend to be used - it's not advisable to use HD disks. One way to get around this is to use a HD drive even for DD media - but don't mix them with multiple drives. Probably the best way to store important data is on harddisk and backup to quality CD/DVD.
Ah, this explains why my disks corrupted so much back in the day!!! :furious:
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Longevity-wise, no, there's little to no difference, except that today the quality as a whole is quite a bit less in the manufacture due to their reduced popularity and sales. For instance, old micro-disks had a dust jacket through the entire internal surface, whereas now there's just a single patch -- arguably this is less effective than the full jacket.
However, there are technical differences between the two.
yep I agree
also today floppies quality is very lame...the plastic is bad and soft....and I imagine that the surface and oxide of the disk is bad quality as well
btw, in the link posted by psxphill says that there is a difference in the oxide coercivity ..660 vs 720 anyways this can be theory....in practice I never found differences...hd disks always worked fine in the amiga and last long......and nobody can affirm correctly which one last long
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I always found pre-formatted 1.44MB disks would frequently failed to format right away on track 0. What I would do is DMS a disk image to it. After that it would reformat just fine. I have no idea about the longevity.
another way to format those pre-formatted 1.44mb disks is format first with no verify then reformat with verify
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another way to format those pre-formatted 1.44mb disks is format first with no verify then reformat with verify
What's the point? Writing those disks several times may seem to solve the problem for the moment but doesn't really change anything longevity wise.