Use PC HD floppy disk in Amiga

rabidgerry · 20 February 2020, 19:33

Hello, I have been looking on line for evidence to suggest that this is possible, but I seem to have hit a brick wall with my research.

What i want to know, can I use a blank PC disk in my Amiga 1200 with classic workbench 3.1 installed? I read that if I cover the second hole on the pc disk that this was possible, however I don't seem to be able to format the disk. It wont allow me and keeps saying "not a dos disk".

Is possible to do this or am I beat?

amiman99 · 20 February 2020, 19:39

You need CrossDos to read DD 720k PC disks, or PC disk driver found in WB 3.1 Storage folder, but it will not boot.

Try to format to 720K on the PC first (Use Win 95 to Win XP), then read on Amiga.

th4t1guy · 20 February 2020, 19:49

I'm not sure how well DD Amiga drives write to those disks, but that tape trick at least works with an HD Amiga drive in an A4000.
But you may run into reliability issues later if you're doing more frequent writes.

torsti76 · 20 February 2020, 19:59

With the internal floppy drives used in the "small box" Amigas (e.g. A1200, A500), you don't even need to cover the HD detection hole. The drives are genuine DD drives that lack the switch that would be activated by that hole.

If the disk can't be formatted in workbench, try X-Copy. In the "Tools" menu it has a format option that can also tell you if your disk is physically bad...

AmigaHope · 20 February 2020, 20:02

Quote:

Originally Posted by amiman99

You need CrossDos to read DD 720k PC disks, or PC disk driver found in WB 3.1 Storage folder, but it will not boot.

Try to format to 720K on the PC first (Use Win 95 to Win XP), then read on Amiga.

Actually that's the exact opposite of what he should do.

HD floppies work at different flux levels than DD floppies. If an HD floppy is ever written to at all by an HD floppy drive, it will push the levels beyond what a DD floppy drive can deal with and it will become unreliable.

This includes preformatted HD floppies, they will work like crap in a DD drive.

The only way to use an HD floppy semi-reliably in a DD drive is to start from a completely blank unformatted state and only ever use it in a DD drive. Even then it is a bad idea.

torsti76 · 20 February 2020, 20:30

Quote:

Originally Posted by AmigaHope

Actually that's the exact opposite of what he should do.

HD floppies work at different flux levels than DD floppies. If an HD floppy is ever written to at all by an HD floppy drive, it will push the levels beyond what a DD floppy drive can deal with and it will become unreliable.

This includes preformatted HD floppies, they will work like crap in a DD drive.

The only way to use an HD floppy semi-reliably in a DD drive is to start from a completely blank unformatted state and only ever use it in a DD drive. Even then it is a bad idea.

But isn't the flux level initialized by (re-)formatting the disk? In the end, it's all only plastic foil impregnated with magnetic particles, or is it?

Retro1234 · 20 February 2020, 20:46

You can use a HD just normally as any Amiga Disk

If you want to use it on PC and Amiga you can only use it as a DD/DS 720K with crossdos and cover the hole for use on PC.

If you want to use it as a HD disk you need a HD drive for Amiga.

Solo Kazuki · 20 February 2020, 21:18

Quote:

Originally Posted by torsti76

But isn't the flux level initialized by (re-)formatting the disk? In the end, it's all only plastic foil impregnated with magnetic particles, or is it?

But it's different type of magnetic material. Usually for DD floppy is used magnetic iron oxide, for HD floppy cobalt-doped iron oxide. They have different magnetic properties and it's like mentioned before - it's not good idea to use HD as DD and vice-versa.

rabidgerry · 20 February 2020, 21:20

I actually will not need it for long, it just so happens I ran out of amiga blanks and I wanted to finish a test install of OS 3.1.4.

So I need cros dos or not? I will not be using in a pc at all. In fact I do not have a pc floppy drive.

Solo Kazuki · 20 February 2020, 21:27

In short time it's useful, problem is when using wrong type for longer time.
As i understand correctly You need use any blank floppy for Amiga? Some disk drives do not handle correctly floppies with uncovered additional hole even if not support HD disks. Just try to cover this hole with tape and then try to format.

rabidgerry · 20 February 2020, 21:31

Oh the hole is already covered, but it did not work. Yes so I only really need the disk to work for a short time and since I had pc disks lying around that had not been used I figured perhaps I could write to one or two of these disks just to complete the install and then not use again.

Retro1234 · 20 February 2020, 21:48

You have to Format it etc

rabidgerry · 20 February 2020, 21:52

Yes I tried that and got the error saying it was not a dos disk.

th4t1guy · 20 February 2020, 22:04

You could try a few other floppies to see if you can get one working. However, considering the age of drives and disks, doing this was already unreliable when they were new, it's not going to be any better now.

rabidgerry · 20 February 2020, 22:18

Weirdly I did what you said and it worked without issue. I inserted the disk, right clicked and full formatted. Then I used ADF2disk to write an ADF to the disk. Worked a treat.

So is this bad for my disk drive? It's only a temporary disk really anyways. I don't use floppies at all apart from the odd occasion such as this.

amiman99 · 20 February 2020, 22:26

Quote:

Originally Posted by rabidgerry

Weirdly I did what you said and it worked without issue. I inserted the disk, right clicked and full formatted. Then I used ADF2disk to write an ADF to the disk. Worked a treat.

So is this bad for my disk drive? It's only a temporary disk really anyways. I don't use floppies at all apart from the odd occasion such as this.

You'll be fine, I got bunch of HD disks formatted to DD, and my disk drives are fine.

torsti76 · 20 February 2020, 22:28

Quote:

Originally Posted by rabidgerry

Weirdly I did what you said and it worked without issue. I inserted the disk, right clicked and full formatted. Then I used ADF2disk to write an ADF to the disk. Worked a treat.

So is this bad for my disk drive? It's only a temporary disk really anyways. I don't use floppies at all apart from the odd occasion such as this.

Well, the floppy material ages and tends more to come loose and deposit on the drives head. However, floppies did this all the time even when they were state of the art. So, yes, it will leading to your drive wearing down a bit more, but no, I don't think that the type of disk matters much in this regard...

rabidgerry · 20 February 2020, 22:31

Excellent! It really was easy to do. I thought perhaps some black magic was involved. I guess that disk I tried is just screwed.

Do I need the hole covered up then or not?

th4t1guy · 20 February 2020, 22:34

You only need it covered if you use it in a drive that supports HD (a4000 for example, and possibly any modded PC drive that hasn't disabled that switch....not sure on that one tho).

Just don't put any data you want kept long term on there and you should be fine.

nobody · 21 February 2020, 07:58

It works if the floppy disk and the floppy drive are good. They don't hold data for long, i had converted some hd disks from adf 7-8 years ago and they don't boot (some of them).

20 February 2020, 19:33	#1
rabidgerry Registered User Join Date: Nov 2018 Location: Belfast Posts: 1,512	Use PC HD floppy disk in Amiga Hello, I have been looking on line for evidence to suggest that this is possible, but I seem to have hit a brick wall with my research. What i want to know, can I use a blank PC disk in my Amiga 1200 with classic workbench 3.1 installed? I read that if I cover the second hole on the pc disk that this was possible, however I don't seem to be able to format the disk. It wont allow me and keeps saying "not a dos disk". Is possible to do this or am I beat?

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20 February 2020, 19:39	#2
amiman99 Registered User Join Date: Sep 2009 Location: San Antonio, TX USA Age: 50 Posts: 1,184	You need CrossDos to read DD 720k PC disks, or PC disk driver found in WB 3.1 Storage folder, but it will not boot. Try to format to 720K on the PC first (Use Win 95 to Win XP), then read on Amiga.

20 February 2020, 19:49	#3
th4t1guy Registered User Join Date: Mar 2002 Location: Kansas City, MO, USA Posts: 683	I'm not sure how well DD Amiga drives write to those disks, but that tape trick at least works with an HD Amiga drive in an A4000. But you may run into reliability issues later if you're doing more frequent writes.

20 February 2020, 19:59	#4
torsti76 Registered User Join Date: May 2018 Location: Germany, Baden-Wuerttemberg Posts: 387	With the internal floppy drives used in the "small box" Amigas (e.g. A1200, A500), you don't even need to cover the HD detection hole. The drives are genuine DD drives that lack the switch that would be activated by that hole. If the disk can't be formatted in workbench, try X-Copy. In the "Tools" menu it has a format option that can also tell you if your disk is physically bad...

20 February 2020, 20:46	#7
Retro1234 Phone Homer Join Date: Jun 2006 Location: 5150 Posts: 5,773	You can use a HD just normally as any Amiga Disk If you want to use it on PC and Amiga you can only use it as a DD/DS 720K with crossdos and cover the hole for use on PC. If you want to use it as a HD disk you need a HD drive for Amiga.

20 February 2020, 21:20	#9
rabidgerry Registered User Join Date: Nov 2018 Location: Belfast Posts: 1,512	I actually will not need it for long, it just so happens I ran out of amiga blanks and I wanted to finish a test install of OS 3.1.4. So I need cros dos or not? I will not be using in a pc at all. In fact I do not have a pc floppy drive.

20 February 2020, 21:27	#10
Solo Kazuki Registered User Join Date: Sep 2004 Location: Poland Posts: 1,301	In short time it's useful, problem is when using wrong type for longer time. As i understand correctly You need use any blank floppy for Amiga? Some disk drives do not handle correctly floppies with uncovered additional hole even if not support HD disks. Just try to cover this hole with tape and then try to format.

20 February 2020, 21:31	#11
rabidgerry Registered User Join Date: Nov 2018 Location: Belfast Posts: 1,512	Oh the hole is already covered, but it did not work. Yes so I only really need the disk to work for a short time and since I had pc disks lying around that had not been used I figured perhaps I could write to one or two of these disks just to complete the install and then not use again.

20 February 2020, 21:48	#12
Retro1234 Phone Homer Join Date: Jun 2006 Location: 5150 Posts: 5,773	You have to Format it etc

20 February 2020, 21:52	#13
rabidgerry Registered User Join Date: Nov 2018 Location: Belfast Posts: 1,512	Yes I tried that and got the error saying it was not a dos disk.

20 February 2020, 22:04	#14
th4t1guy Registered User Join Date: Mar 2002 Location: Kansas City, MO, USA Posts: 683	You could try a few other floppies to see if you can get one working. However, considering the age of drives and disks, doing this was already unreliable when they were new, it's not going to be any better now.

20 February 2020, 22:18	#15
rabidgerry Registered User Join Date: Nov 2018 Location: Belfast Posts: 1,512	Weirdly I did what you said and it worked without issue. I inserted the disk, right clicked and full formatted. Then I used ADF2disk to write an ADF to the disk. Worked a treat. So is this bad for my disk drive? It's only a temporary disk really anyways. I don't use floppies at all apart from the odd occasion such as this.

20 February 2020, 22:31	#18
rabidgerry Registered User Join Date: Nov 2018 Location: Belfast Posts: 1,512	Excellent! It really was easy to do. I thought perhaps some black magic was involved. I guess that disk I tried is just screwed. Do I need the hole covered up then or not?

20 February 2020, 22:34	#19
th4t1guy Registered User Join Date: Mar 2002 Location: Kansas City, MO, USA Posts: 683	You only need it covered if you use it in a drive that supports HD (a4000 for example, and possibly any modded PC drive that hasn't disabled that switch....not sure on that one tho). Just don't put any data you want kept long term on there and you should be fine.

21 February 2020, 07:58	#20
nobody Registered User Join Date: Dec 2013 Location: GR Age: 46 Posts: 1,416	It works if the floppy disk and the floppy drive are good. They don't hold data for long, i had converted some hd disks from adf 7-8 years ago and they don't boot (some of them).

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