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[amiman99]

I have another idea,
Go here http://bootdisk.com/bootdisk.htm get win95 or dos bootdisk.
Boot with one of those disks, then use the command to format for 720K disks.

Some Amiga drives don't like to format HD disks, maybe that's the problem.

[Piru]

Originally Posted by motrucker

The high density disks have more tracks

No they don't. They have exactly the same 80 tracks.

[Thorham]

Originally Posted by amiman99

I have another idea,
Go here http://bootdisk.com/bootdisk.htm get win95 or dos bootdisk.
Boot with one of those disks, then use the command to format for 720K disks.

Some Amiga drives don't like to format HD disks, maybe that's the problem.

The OP wants Amiga formatted disks, so this won't work.

[spirantho]

If you want to use a floppy disk on an Amiga, first you need to make sure your floppy drive is working, so test with a known good disk.
Second, don't bother trying to use a PC unless you have a Catweasel. Use an Amiga; a PC can do it but it's very complicated and you need two disk drives.
Thirdly, use Double Density disks, not High Density. It may work on certain HD disks but don't be surprised if it fails to format; even if it does format, expect to lose data. Sometimes you get lucky, and an HD disk will work for a while, but never trust data to one. HD disks require a stronger magnetic field than DD disks, so your old A500 drive probably can't magnetise the surface enough.

You shouldn't have any trouble if you follow that. There's nothing special about Amiga disks or Amiga drives, it's the controller that's special.

[motrucker]

Originally Posted by Piru

No they don't. They have exactly the same 80 tracks.

I'll be damned. I guess I must have look at the 135 tpi years ago, and misread that as the number of tracks. Thank you for pointing that out.
That makes this question all the confusing for me then. Why are HD disks so hard to use on (some?) Amigas? After reading the DD and HD disks specs, it does not look there should be any problem.

[spirantho]

They use a different magnetic material for the disk surface....

[smerf]

Originally Posted by sim085

Hello, I have a few new PC floppy disks which work fine on PC. I would like to format these in such a way that I can use them as Amiga floppy disks (not to transfer files between PC and Amiga, but to use them as if Amiga floppy disks).

I had a similar thread in the past but what was suggested then is not working. I have Windows7. I insert the floppy disk and then from command promt I enter the following command:

FORMAT A: /T:80 /N:9

However I get the following output

H:\>FORMAT A: /T:80 /N:9
Insert new disk for drive A:
and press ENTER when ready...
The type of the file system is RAW.

Hi,

Windows does not have a flexible system, by that I mean on formatting disks it can only format 1.44 megs. Even to format 720K disks for the PC platform you have to jump through hoops today. Most PC's today don't even have a floppy disk attachment on them, I have to use a usb floppy on mine.

So you can not in any manner shape or form format an Amiga floppy on a PC.

EXCEPT

If you buy a cat weasel, and are intelligent enough to read the instructions and use it. (sorry I had to put that in since intelligence runs rampant on amiga.org)

So

1. Formating an Amiga disk on a PC machine without added hardware -- not possible.
2. Using added hardware like Cat Weasel -- possible, if you have an IQ for it.
3. Formatting any size PC disk on an Amiga if you have a high density drive (1.44 meg) -- possible.


The new file system is FAT.
Formatting 720K
Invalid media or Track 0 bad - disk unusable.

Does anyone know if I can format a PC disk to use it as an Amiga disk? or this is not possible?

Yes, but only Amiga makes it possible. (880k drive = 720k pc, HD drive = 1.44 & 720k)

smerf

hope you loonies can understand this, if not I will try to make it simpler.
Please read whole blocked paragraph above, my answers to each question is answered within.

[motrucker]

Originally Posted by smerf

Yes, but only Amiga makes it possible. (880k drive = 720k pc, HD drive = 1.44 & 720k)

smerf

hope you loonies can understand this, if not I will try to make it simpler.
Please read whole blocked paragraph above, my answers to each question is answered within.

Another sexual intellectual, huh?

[amiman99]

Originally Posted by Thorham

The OP wants Amiga formatted disks, so this won't work.

Sometimes Amiga does not like HD disks formatted in DD (I have seen that), maybe if you format them to 720k first then you may be able to format to 880k in Amiga.

[Thorham]

Originally Posted by smerf

Yes, but only Amiga makes it possible. (880k drive = 720k pc, HD drive = 1.44 & 720k)

Drive mechanisms aren't 880K. As far as I know Amigas can format double density floppies as 1MB (MFM). The controller on the computer's side determines this. Using GCR, you can fit even more on a DD floppy.

[zipper]

diskspare.device lets you to format 960/984k disks on Amiga.

[Piru]

Originally Posted by spirantho

Thirdly, use Double Density disks, not High Density.

This is a fair point, even though the disks are similar and you might get lucky, it much depends on the specific media and the health of the drive. For instance when things start to get out of calibration the first thing to fail are the "borderline" media.

HD disks require a stronger magnetic field than DD disks, so your old A500 drive probably can't magnetise the surface enough.

Actually it's the other way around: DD recording strength is higher than HD.

There are ton of information regarding why it may or may not fail. Here's some good discussion with some great information:

http://www.retrotechnology.com/herbs_stuff/guzis.html

In short: If only possible use genuine DD media. Or if not possible make sure to properly erase the floppies before use.

[zipper]

A short clip:
3.5" DS2D and DSHD media are very close in terms of the magnetic properties of the coating. DS2D media generally is coated with an oxide coating with a coercivity of about 660 Oersteds (Oe); DSHD media uses a coating with coercivity of 720 Oe, so it's only a bit "stiffer" magnetically speaking. DSHD also generally uses a smaller particle size, which isn't bad for DS2D use.

So far, so good--it looks as if the HD media will serve passably even if the write current in double-density mode isn't quite as high (lower-coercivity = lower write current needed to "flip" the domains). By the same token, a 2D diskette should work passably in an HD application (bring up any memories of the "puncher" accessories that used to be popular?). [These punches were sold for people to convert then-popular DD diskettes into "looking" like then-rare and expensive HD diskettes, with mixed results. - Herb]

Where things start to get interesting is in the coating thickness. DS2D coats the cookie with a layer about 1.9 microns (um) thick. By comparison the average fine human hair is about 25-30 um thick. (Hair diameter depends on the person and the type of hair, the range is pretty wide; from about 12 to over 100 um for a single hair diameter).

However, the problem arises that DSHD media uses a coating about half that thickness (0.9 um). This is why the cookie in a DSHD 3.5" diskette seems almost transparent if you hold it up to a strong light, while the DS2D variety is opaque

[sim085]

Thanks to everyone for the replies. As I said the relative new "amiga" floppy disks format fine. The very old "amiga" floppy disks (which data is also corrupt) don't format. Then I found some "amiga" floppy disks which when format give an error on some cylinder and then when I format again give an error on another cylinder and the previous cylinder is formatted successfully. The “pc” floppy disks never work and format always fail on cylinder zero.

I understand this might be a problem with the age and amount of dust in the drive … therefore I was wondering; does anyone know how to clean the floppy drive?? need to use any special liquid??

[amiman99]

Originally Posted by Thorham

The OP wants Amiga formatted disks, so this won't work.

Originally Posted by sim085

Thanks to everyone for the replies. As I said the relative new "amiga" floppy disks format fine. The very old "amiga" floppy disks (which data is also corrupt) don't format. Then I found some "amiga" floppy disks which when format give an error on some cylinder and then when I format again give an error on another cylinder and the previous cylinder is formatted successfully. The “pc” floppy disks never work and format always fail on cylinder zero.

I understand this might be a problem with the age and amount of dust in the drive … therefore I was wondering; does anyone know how to clean the floppy drive?? need to use any special liquid??

If you are not affraid to open you floppy drive then you can use cotton swabs and 91% isopropyl alcohol. Just swab both heads clean.