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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Super TWiT on May 20, 2010, 04:58:27 PM

Title: HD Disks as DD Disks?
Post by: Super TWiT on May 20, 2010, 04:58:27 PM
I have to admit that I use hd floppies on my amiga 500. Is it okay to do? Some people say no others say yes. I have had no major problems so far.
Title: Re: HD Disks as DD Disks?
Post by: jj on May 20, 2010, 04:59:18 PM
I never had any problems either.  But apparently it can cause issues.
Title: Re: HD Disks as DD Disks?
Post by: Super TWiT on May 20, 2010, 05:00:17 PM
To be honest, data loss isn't that big of a deal for me because I have adf backups.
Title: Re: HD Disks as DD Disks?
Post by: save2600 on May 20, 2010, 05:08:50 PM
Only recently have I noticed some funkiness using HD disks as DD. Seems some drives are more sensitive than others, but for the most part - I've had great luck using HD disks as well.
Title: Re: HD Disks as DD Disks?
Post by: Super TWiT on May 20, 2010, 05:10:20 PM
Is it damaging to the drive at all?
Title: Re: HD Disks as DD Disks?
Post by: runequester on May 20, 2010, 05:23:40 PM
Back in the day, I used HD disks for my 1200, and never once had a problem.

A friend of mine used them to, but his 500 wouldnt format them, so he'd give them to me to format,then they'd work fine
Title: Re: HD Disks as DD Disks?
Post by: Ilwrath on May 20, 2010, 08:09:52 PM
Quote
Is it damaging to the drive at all?
Not that I know of.  I suppose if you let a drive excessively grind/retry reads and writes, it could cause additional wear to the unit, but not beyond that of trying to the same actions to a faulty DD disk.

I have had occasional problems with writing and data retention on HD disks, but really, with everything being on ADF and just written to floppy for temporary use, it shouldn't be an issue.

(Oh, also, remember if you later try to use that DD formatted disk on an Amiga 3000/4000, cover the hole with tape or it'll try to interpret the disk as an HD disk and tell you it's unformatted.  ;)  )
Title: Re: HD Disks as DD Disks?
Post by: joekster on May 20, 2010, 09:15:12 PM
Never, ever had a problem with HD floppies used as DD. However, I have had some HD drives require the HD hole to be closed in order to work with these floppies. Makes sense since you wouldn't want a HD drive to misdetect a DD floppy as HD...
Title: Re: HD Disks as DD Disks?
Post by: Colani1200 on May 21, 2010, 07:18:14 PM
Quote from: joekster;559793
I have had some HD drives require the HD hole to be closed in order to work with these floppies.


My A1200 requires that although it is actually a DD drive. But I think an Escom one... I guess it would be possible to desolder the HD sensor of the drive to get rid of this.
Title: Re: HD Disks as DD Disks?
Post by: zipper on May 21, 2010, 07:36:22 PM
Escom ones are modified HD drives AFAIK.
Title: Re: HD Disks as DD Disks?
Post by: chris on May 21, 2010, 09:26:29 PM
Quote from: Super TWiT;559750
I have to admit that I use hd floppies on my amiga 500. Is it okay to do? Some people say no others say yes. I have had no major problems so far.


I found them quite unreliable at times, but generally they worked OK.  May have just been cheap quality disks though.

I also used to use DD floppies formatted as HD in the Acorn RiscPCs, never had a problem with them either (RISC OS didn't care whether the HD hole was present or not IIRC).

Chris
Title: Re: HD Disks as DD Disks?
Post by: kvasir on May 21, 2010, 09:47:35 PM
I've had a few problems, though only long-term. The data seems to "bitrot" quicker, probably an alignment issues that would go otherwise un-noticed. But for transferring data from windows machines to my Amiga, it worked well. The quickest I've noticed any problems was a week, and that particular disk was subjected to environments most jungle animals would find too humid. Only real issue was formatting the disk to DD, PC-side you of course need to scotch-tape the second hole, and I've yet to find an XP install that can format it via the GUI. Plus I can never remember the command line for formatting a 720k.. (format /? is usually my first call to said command). Also, found CrossDOS can actually format 720k better than XP can. But for just temporary Amiga storage/transfers they work fine.
Title: Re: HD Disks as DD Disks?
Post by: rkauer on May 22, 2010, 03:25:33 AM
Problem is hysteresis and coercivity of the HD magnetic coat, which is totally different (or at least different enough) to keep the data.
Title: Re: HD Disks as DD Disks?
Post by: gertsy on May 22, 2010, 09:31:18 AM
I've used Verbatim HD disks(taped) for 15 or so years.  rarely have a problem.  If I do its usually the disk media itself. Sometimes used other disks but always go back.
Hard to get tme now, but I have a nice store.

Gertsy
Title: Re: HD Disks as DD Disks?
Post by: lauri.lotvonen on May 22, 2010, 11:35:26 AM
I have some issues using HD disks in my 1200... When I format the HD disk in WB, seems that theres no problem, but when trying to write an adf back to it using AExplorer, always gives me a 'error reading track'.
My external drive works with HD disks flawlessly, reading/writing.