35 replies to this topic

[birdie3]

I found a sealed box of double sided, double density floppy disks at a thift store the other day. Are these compatible with the Atari 810, 1050, XF551 etc.. ? Hopefully someone can answer this for me. Thanks!!

[deathtrappomegranate]

Yup, you should be OK with them.

[birdie3]

I don't need to notch them or anything funky like that?

[remowilliams]

birdie3, on Fri Dec 2, 2005 8:28 PM, said:

I don't need to notch them or anything funky like that?

You can notch the left side if you want to write on the "back" of the floppies. Otherwise, no.

[DonutCity]

Interesting - so the DSDD disk will work in the 810 drive?

[AlmostRice]

DonutCity, on Sat Dec 3, 2005 9:41 AM, said:

Interesting - so the DSDD disk will work in the 810 drive?

yes, the 810 is sssd. The disks are backwards compatible. They should have only one notch if they are new. If you notch the opposite side, you can turn them flip them to use both sides. Hence, they are sometimes called flippies instead of floppies.

Edited by AlmostRice, Sat Dec 3, 2005 10:01 AM.

[Plastron]

hehehehe

i assume they are 5 1/4 disks then as you did not say.

There were bigger and smaller floppies

[birdie3]

Yes. They are 5.25 floppies. Now I need a disk drive... Atari 8-bit that is,

[LYNXGUY]

My best friend Chris told me than any 5.25 floppy can be formatted by an 8bit Atari computer and used without any problems.

[Sikor]

LYNXGUY, on Tue Dec 20, 2005 3:21 PM, said:

My best friend Chris told me than any 5.25 floppy can be formatted by an 8bit Atari computer and used without any problems.

Wrong!!! With HD disk may be some problems - sometimes data losts. It is beacouse DSHD disk are other magnetic fields form then DSDD (96DPI for HD, 48DPI for DD and SD disks). Of course simetimes disk drives read and write HD disk without any problems, but only for your own risk, and are some problems with read it in other drive. O.K. - I use sometimes HD disk, but only for backup storage...

[Rybags]

I've even heard of "hard sectored" floppies being fine with a 1050.

Modern (OK, 15 year-old) HD disks might pose a problem. Since they are used in higher density configurations, they tend to have a thinner oxide coating, since HD floppy drives use a weaker field.

[Fröhn]

Rybags, on Wed Dec 21, 2005 3:40 PM, said:

Modern (OK, 15 year-old) HD disks might pose a problem.  Since they are used in higher density configurations, they tend to have a thinner oxide coating, since HD floppy drives use a weaker field.

I think it is the other way round: HD drives use a stronger magnetic field. I had formatted some DD disks in a HD drive and could not reformat them in a DD drive anymore. Also, if you write data to a HD disk with a DD drive the data is usually not stable, it will get weaker and weaker. A strong hint that the DD drive did not pass the minimum magnetization level.

[javiero]

You can work with HD disks on the XF551, at least i can with mine. I can format, re-format with no problems at all... Anyway just go and get those disks, if you don´t want them sell them on e-bay so we all have a chance to get them...

[ijor]

5.25 high density disks use a completely different magnetic coating. They have a bigger coercivity. Coercivity measures the resistance of the media to magnetic fields. Hence these disks require a much stronger magnetic field to be written or erased.

In magnetic recording, magnetic field is usually measured in units called Oersted (Oe). The Oe magnetic used with 5.25 high density disks is usually about 2.5 times stronger than the one used in DD (or SD) ones. Contrast this with 3.5 disks, where HD ones use only about 10% stronger magnetic field than 3.5 DD ones.

For this reason you normally cannot use HD disks on DD drives (or on HD drives in DD mode for that matter).

[remowilliams]

Fröhn, on Wed Dec 21, 2005 11:18 AM, said:

I think it is the other way round: HD drives use a stronger magnetic field. I had formatted some DD disks in a HD drive and could not reformat them in a DD drive anymore. Also, if you write data to a HD disk with a DD drive the data is usually not stable, it will get weaker and weaker. A strong hint that the DD drive did not pass the minimum magnetization level.

Yup, hence the "here today, gone tomorrow" data problem of writing HD 5.25s in a DD drive.

[jaybird3rd]

The XF551 is actually capable of using DSDD diskettes in their full 360K capacity (assuming you're using the correct DOS), so it is not necessary to notch these if you're using them for simple data storage or to store game binaries. A lot of larger programs that require the older 90K format of the 810, however, are configured to read data from both sides of the disk and will ask you to switch to one or the other as needed. If you're interested in making backups of these, you may find it necessary to notch your disks. I'd recommend getting a proper disk notcher for this; it's a lot easier (and safer) than measuring and punching out the holes and B&C ComputerVisions sells them for only a few dollars.

Does anyone happen to know whether the XF551 is capable of reading/writing to flippies as easily as the 810 and 1050 could? I know it uses a standard IBM-compatible drive mech, and from what I remember, those aren't nearly as compatible with flippies. I'd test it with my XF551, but I'm using it with a 3.5-inch drive mech at the moment.

[Gunstar]

Plastron, on Sat Dec 3, 2005 4:46 PM, said:

hehehehe

i assume they are 5 1/4 disks then as you did not say.

There were bigger and smaller floppies

I remember when I was in grade school, just before the Apple II's made theire way into the nation's schools, we had an old computer with 8" disks! Anyway, I found 3 packs of radioshack/tandy 5 1/4" floppies that were still shrink-wrapped at my local thrift shop! I'm set for a while now, but I grab any 5 1/4 or 3.5 inch DD and HD now whenever I see them at the thrift/goodwill, becuase they are getting rarer and even HD floppies will probably be discontinued completely,soon now. I need a supply of them to last me as long as I and my computers live.

[ijor]

jaybird3rd, on Tue Dec 27, 2005 4:59 PM, said:

Does anyone happen to know whether the XF551 is capable of reading/writing to flippies as easily as the 810 and 1050 could?  I know it uses a standard IBM-compatible drive mech, and from what I remember, those aren't nearly as compatible with flippies.

It depends on the specific drive mechanism. Some XF-551 have mechanism that cannot access the flippy side at all, some others can. But in no case you can format the flippy side with an XF-551 without some hardware mod.

Btw, I don't think there is any need to panic about floppy supplies. Dealers have a lot of stock. You can even buy brand new boxes of 8" floppies if you want.

[birdie3]

Here's another question.

Can I reformat IBM formatted DS/DD 5.25 disks to work with the Atari 8 bit computers?

I haven't picked up an Atari DOS yet and I have a few sealed boxes of IBM formatted DS/DD disks that I would like to reformat for use with Atari if possible.

[Famicoman]

I think it is possible. All Disks are the same (basically).

"The situation was even more complex with 5¼-inch diskettes. The head gap of a 1200 KB drive is shorter than that of a 360 KB drive, but will format, read and write 360 KB diskettes with apparent success. A blank 360 KB disk formatted and written on a 1200 KB drive can be taken to a 360 KB drive without problems, similarly a disk formatted on a 360 KB drive can be used on a 1200 KB drive. But a disk written on a 360 KB drive and updated on a 1200 KB drive becomes permanently unreadable on any 360 KB drive, owing to the incompatibility of the track widths. There are several other 'bad' scenarios.

Prior to the problems with head and track size, there was a period when just trying to figure out which side of a "single sided" diskette was the right side was a problem. Both Radio Shack and Apple used 360 KB single sided 5¼-inch disks, and both sold disks labeled "single sided" were certified for use on only one side, even though they in fact were coated in magnetic material on both sides. The irony was that the disks would work on both Radio Shack and Apple machines, yet the Radio Shack TRS-80 Model I computers used one side and the Apple II machines used the other, regardless of whether there was software available which could make sense of the other format."

-Wikipedia

Edited by Famicoman, Thu Jan 5, 2006 9:39 PM.

[Artlover]

Famicoman, on Thu Jan 5, 2006 9:35 PM, said:

-Wikipedia

'nuff said.

[Bruce Tomlin]

birdie3, on Thu Jan 5, 2006 10:29 PM, said:

Here's another question.

Can I reformat IBM formatted DS/DD 5.25 disks to work with the Atari 8 bit computers?

Yes, but not HD disks.

In fact, I've even found disks where the front side was Atari formatted, and the back side still had the original IBM (9x512) formatting from when the disks were new.

[Rybags]

I could be wrong here, but I think Atari SS drives actually write to what would be called Side 2 of DS disks.

[Almost Rice]

Rybags, on Thu Jan 5, 2006 11:26 PM, said:

I could be wrong here, but I think Atari SS drives actually write to what would be called Side 2 of DS disks.

I noticed this too, but I just thought thats how SS disk drives worked.

[ijor]

Rybags, on Thu Jan 5, 2006 11:26 PM, said:

I could be wrong here, but I think Atari SS drives actually write to what would be called Side 2 of DS disks.

No, most SS drives, including Atari ones write to side 0 (or 1 if you want) of a DS drive.

What might be confusing you is that the first (or only) side, is actually the back one. That is, SS drives have only a head assembly at the bottom, which correspond to the first head of a DD drive. So that, i.e., in an Atari/C64 flippy disk, the side labeled Atari has actually the C64 data and vice versa.

The reason for this was in first place, that it is much simpler to produce the bottom head than the top one that it’s “floating”. And when DS drives were designed, the goal was to maintain backwards compatibility with SS drives.