OLD floppy problem (5 1/4)

zombor · n00b Joined: 05 Nov 2004 Posts: 54

OK, I got these very old 5 1/4 floppies someone needs info from (dont ask why, i dont know). So i ebayed a drive and hooked it up to my windows machine, and when i click on the drive, it give me some crazy error message, so i decided to try it out in gentoo.

I booted off the liveCD and

Nijinski · Posted: Wed Aug 10, 2005 9:23 pm Post subject:

You did remember to go into the BIOS and tell your machine it was a 1.2 drive ?
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NeddySeagoon · Posted: Wed Aug 10, 2005 9:29 pm Post subject:

zombor,

There are two different interfaces for 5 1/4" drives. They look the same but one will not work in a PC.
I forget the details now, something to do with the media change signal I think. If you have a non PC drive. It cannot be made to work.

To add to the fun, 5 1/4" drives came in 360km 720k and 1.2Mb.
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

zombor · n00b Joined: 05 Nov 2004 Posts: 54

Yes, it is recognised in BIOS as a 1.2Mb 5 1/4 drive.

I got a special floppy cable for it that has both the old "card" interface for 5 1/4 drives, and regular 3 1/2 drives as well.

Do the disks have to match the capacity of the drive?!? I am old-school, but I havent even seen a 5 1/4 in like 15 years...

pilla · Posted: Wed Aug 10, 2005 10:55 pm Post subject:

A 1.2 MB 5 1/4 drive? I don't remember having heard of one of these.......
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zombor · n00b Joined: 05 Nov 2004 Posts: 54

NeddySeagoon · Posted: Wed Aug 10, 2005 11:42 pm Post subject:

zombor,

You can read any of the lower capacity 5 1/4" floppies in a 1.2Mb drive.
Writing lower capacity disks is a bit involved and depends on where they were formatted and where you want to read them afterwards.

1.2Mb drives have half the track width of the lower densities. When you write a 720kb floppy, that was formatted in a 720kb drive, it writes down the middle of the wider track. This track now has old data at the outside and new data in the centre. Your 720kb drive can no longer read that part of the floppy ...
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

AaronPPC · Guru Joined: 29 May 2005 Posts: 522 Location: Tucson, AZ

If you get it to work you have to tell us how sloooow it seems.

The nice thing about 5 1/4" disks was that you never had to explain to anyboday why their called floppies.
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--Aaron

zombor · n00b Joined: 05 Nov 2004 Posts: 54

NeddySeagoon · Posted: Thu Aug 11, 2005 10:07 am Post subject:

AaronPPC,

1.2 Mb 5 1/4 floppies are the same speed as 1.44Mb 3 1/2
So you know how slow it is.
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

DaveArb · Guru Joined: 29 Apr 2004 Posts: 510 Location: Texas, USA

pilla · Posted: Thu Aug 11, 2005 2:25 pm Post subject:

zombor · n00b Joined: 05 Nov 2004 Posts: 54

DaveArb · Guru Joined: 29 Apr 2004 Posts: 510 Location: Texas, USA

I think 500K are double-sided double-density (360K formatted), not high density 1.2MB formatted/2MB unformatted. Back when I worked with floppies, SCO UNIX required different /dev/ files for each different format. I'm afraid I don't know how they work in Linux.

Dave

jschellhaass · Guru Joined: 20 Jan 2004 Posts: 341

The good ole days

SSSD - Single Sided Single Density 90k - Atari 800 - Anyone remember Elephant disks and notching'em with a paper punch for double sided use?
SSDD - Single Sided Double Density 180k
DSDD - Double Sided Double Density - 360k

I'll have to see if I still have a 5.25 drive laying around and see if works under Gentoo.

jeff

NeddySeagoon · Posted: Thu Aug 11, 2005 9:25 pm Post subject:

DaveArb,

Linux required different /dev/ entries for formatting floppies but they should all read and write on same one provided they use standard formats. Linux supports other block sizes than 512b and up to 82 tracks, which some floppies can do too.
Reading and writing to such nonstandard formats is the users problem.

I still have a 5 1/4" 1.2 Mb drive and some blank media to play with. 've not used it for about 5 years.

I was wrong about the 720kb being a 5 1/4" format. It was 180kb, 360kb and 1.2 Mb
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

zombor · n00b Joined: 05 Nov 2004 Posts: 54

NeddySeagoon · Posted: Thu Aug 11, 2005 9:48 pm Post subject:

zombor,

500k is the unformatted size, (1.44Mb disks are marked 2Mb) It sounds like they are 360kb (formatted) disks.
Windows 3.11 or a 386?
Maybe. More likely Word for DOS (I rememebr Version 5.0)

A 386 would have had a 1.2Mb drive, it may have had a 1.44Mb drive too. If you have obtained a 360kb drive, it would not read 360kb disks formatted in a 1.2Mb drive because the tracks are only half the width they need to be.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

zombor · n00b Joined: 05 Nov 2004 Posts: 54

NeddySeagoon · Posted: Sat Aug 13, 2005 12:59 pm Post subject:

zombor,

Yes. A 1.2Mb drive will read the mess created by mixed writes to 360kB media.

When you attempt to mount a floppy, the drive should spin up does it?

A few other anachronisims to check.
A floppy controller supports 4 drives but in PCs fitted with hard drives only two are used.
Floppy cables fitted to most modern systems have 4 wires split out of the ribbon and twsted between one drive connecot and the other. This twist swaps over the drive select lines for drives A:\ and B:\. It means that the drives are always jumpered as drive A:\ but the position determines which drive they respond as.
Older systems (no twinst in the drive select lines) needed the floppy drives to be jumpered, and 5 1/4 drives were provided with a 4 way header and jumper (fit one) to choose if the drive should respond as A, B, C, or D.

Assembling parts today, you will have a drive with the drive select jumper and a cable with the twist. If the drive is not jumpered as drive A:\, it will not work at all with a cable with a twist.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.