18 Dec
2004
18 Dec
'04
12:25 p.m.
I think we've discussed this before. Sorry if we're re-treading old
ground.
I'm trying to read a disk an old double-density PC formatted disk on a
high-density drive. I can read the directory and certain small files just
fine, but any files that are larger than a few sectors (or perhaps that
span a track) return "Sector Not Found" errors. What is the deal with
that?
This is under DOS 6.22. Is there a way to get DOS to recognize that this
is a double-density disk and to perform whatever internal magic is
necessary to read the disk properly? Or is this an issue of hardware?
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
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19 Dec
19 Dec
12:25 a.m.
From: "Vintage Computer Festival" <vcf(a)siconic.com>
Subject: Problems reading older disk on newer drive
I'm trying to read a disk an old double-density PC
formatted disk on a
high-density drive. I can read the directory and certain small files just
fine, but any files that are larger than a few sectors (or perhaps that
span a track) return "Sector Not Found" errors.
This is under DOS 6.22. Is there a way to get DOS to recognize that this
is a double-density disk and to perform whatever internal magic is
necessary to read the disk properly? Or is this an issue of hardware?
Normally, there would not be a problem, supposing it is a 360K disk (I guess
you are talking about 5.25" disks).
What I _have_ seen, is that "modern" BIOS'es have problems / cannot read
disks formatted as 320K. Back in the old days, 5.25" disks came in even more
flavours, like 160K (I've never seen an 80K 5.25" though)
I cant find my DOS manuals right now, but there used to be a function in
DEVICE in CONFIG.SYS where you could do some rather clever things with
regard to disk formats.
If your Octopus system had been working, you could have done a Transfer /
Input / Floppy / Analyse. This will also reveal if it is a proper MS-DOS /
PC-DOS disk, or some knock-off. There were some DOS OEM versions around
(Sord, for one), which could read and write 360K disks, but puked when
presented for 1.2M disks.
Nico
12:47 a.m.
On Sun, 19 Dec 2004, Nico de Jong wrote:
Normally, there would not be a problem, supposing it
is a 360K disk (I guess
you are talking about 5.25" disks).
What I _have_ seen, is that "modern" BIOS'es have problems / cannot read
disks formatted as 320K. Back in the old days, 5.25" disks came in even more
flavours, like 160K (I've never seen an 80K 5.25" though)
Somewhere I have a list of the FATid byte values for all the
IBM and MSDOS 5.25" diskettes. Basically they include:
sides density spt capacity
1 double 8 160k
1 double 9 180k
2 double 8 320k
2 double 9 360k
spt means 'sectors per track' physical
Then there's issues with @#$%^ IBM (or m'soft) looking for
text in the boot sector and not just that FATid (the 1st byte
of each FAT) to ID disks, rendering otherwise-proper MSDOS
diskettes unusable.
AFAIK, IBM never supported single-density. The hardware isn't
the problem, there's no FATid defined for it. And who wants
86K diskettes, anyways?
1:13 a.m.
From: "Tom Jennings" <tomj(a)wps.com>
Then there's issues with @#$%^ IBM (or m'soft) looking for
text in the boot sector and not just that FATid (the 1st byte
of each FAT) to ID disks, rendering otherwise-proper MSDOS
diskettes unusable.
A related "bug" is the following (maybe even the same?)
When I format 3.5" disks on my present conversion system, and insert them in
an IBM or Windows system with virus check software, it will speak up and say
it found a Kitty virus. Extensive forensic work has shown that this is not
the case; the problem is that there is a byte somewhere (can't remember if
is is bootsector or FAT), which according to MS-DOS is un-used.
Nico
1:31 a.m.
On Sun, 19 Dec 2004, Nico de Jong wrote:
Ahh, the Inexorable March of Progress. It must be better -- it's newer!
PS:
As I was getting vietnamese food to go tonight, a counter kid had
a Univ. Southern. Calif. T-shirt on, the obverse of which said
"So and So Famous Person
department for the
commercialization of technology"
So stupidity has gone institutional. And people think I'm crazy!
Then
there's issues with @#$%^ IBM (or m'soft) looking for
text in the boot sector and not just that FATid (the 1st byte
of each FAT) to ID disks, rendering otherwise-proper MSDOS
diskettes unusable.
A related "bug" is the following (maybe even the same?)
When I format 3.5" disks on my present conversion system, and insert them in
an IBM or Windows system with virus check software, it will speak up and say
it found a Kitty virus. Extensive forensic work has shown that this is not
the case; the problem is that there is a byte somewhere (can't remember if
is is bootsector or FAT), which according to MS-DOS is un-used. 
11:30 a.m.
>>>> "Nico" == Nico de Jong
<nico(a)farumdata.dk> writes:
Nico> From: "Vintage Computer Festival" <vcf(a)siconic.com> Subject:
Nico> Problems reading older disk on newer drive
> I'm trying to read a disk an old
double-density PC formatted disk
> on a high-density drive. I can read the directory and certain
> small files just fine, but any files that are larger than a few
> sectors (or perhaps that span a track) return "Sector Not Found"
> errors. This is under DOS 6.22. Is there a way to get DOS to
> recognize that this is a double-density disk and to perform
> whatever internal magic is necessary to read the disk properly?
> Or is this an issue of hardware?
Nico> Normally, there would not be a problem, supposing it is a 360K
Nico> disk (I guess you are talking about 5.25" disks). What I
Nico> _have_ seen, is that "modern" BIOS'es have problems / cannot
Nico> read disks formatted as 320K. Back in the old days, 5.25" disks
Nico> came in even more flavours, like 160K (I've never seen an 80K
Nico> 5.25" though)
Nico> I cant find my DOS manuals right now, but there used to be a
Nico> function in DEVICE in CONFIG.SYS where you could do some rather
Nico> clever things with regard to disk formats.
In Linux you can get the floppy driver to read all sorts of weird
formats; check out the docs. (I forgot where the details are.) For
example, I found that I could have Linux read and write DEC RX50
format floppies, which are 5.25 inch floppies with 10 sectors (not the
usual 9) per track.
paul
12:52 p.m.
On Sun, 19 Dec 2004, Paul Koning wrote:
In Linux you can get the floppy driver to read all
sorts of weird
formats; check out the docs. (I forgot where the details are.) For
example, I found that I could have Linux read and write DEC RX50
format floppies, which are 5.25 inch floppies with 10 sectors (not the
usual 9) per track.
Those are the m tools, they're great!
7:22 a.m.
Is it possible it's an 8 sector disk before dos 2.25?
----- Original Message -----
From: "Vintage Computer Festival" <vcf(a)siconic.com>
To: "Classic Computers Mailing List" <cctalk(a)classiccmp.org>
Sent: Saturday, December 18, 2004 12:25 PM
Subject: Problems reading older disk on newer drive
I think we've discussed this before. Sorry if we're re-treading old
ground.
I'm trying to read a disk an old double-density PC formatted disk on a
high-density drive. I can read the directory and certain small files just
fine, but any files that are larger than a few sectors (or perhaps that
span a track) return "Sector Not Found" errors. What is the deal with
that?
This is under DOS 6.22. Is there a way to get DOS to recognize that this
is a double-density disk and to perform whatever internal magic is
necessary to read the disk properly? Or is this an issue of hardware?
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger
http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage
mputers ]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]
12:51 p.m.
On Sun, 19 Dec 2004, Bill Girnius wrote:
Is it possible it's an 8 sector disk before dos
2.25?
Well sellam's mail said "PC" so I assumed IBM feces type
computer. But yes, there were many MSDOS diskette formats before
IBM, and even before MSDOS, when it was 86DOS; I think it had
the same FAT structure, I just don't recall.
From the start however Microsoft (in one of their good
ideas,
presumably after the debacle of CP/M diskette formats) STRONGLY
SUGGESTED the use of a table of diskette formats ID's with a
particular value of FATid byte. Unsurprisingly the formats were
more or less all you could cram on a soft-sectored diskette. Both
8" and 5.25" were given.
For some reason, I don't recall and may never have known, FATids
run from 0f8h - 0feh. That's not many. So there were overlaps,
but the intent (...) was FATid of FE (8" 26 sector I think)
could be re-used on a (say) 3" floppy with no confusion.
But then PCDOS did that irritating
check-for-data-in-the-boot-sector thing.
The unix M tools should be able to read any properly formatted
diskette, even if a wondows machine wont.
----- Original Message ----- From: "Vintage
Computer Festival"
<vcf(a)siconic.com>
To: "Classic Computers Mailing List" <cctalk(a)classiccmp.org>
Sent: Saturday, December 18, 2004 12:25 PM
Subject: Problems reading older disk on newer drive
I think we've discussed this before. Sorry if we're re-treading old
ground.
I'm trying to read a disk an old double-density PC formatted disk on a
high-density drive. I can read the directory and certain small files
just
fine, but any files that are larger than a few sectors (or perhaps that
span a track) return "Sector Not Found" errors. What is the deal with
that?
This is under DOS 6.22. Is there a way to get DOS to recognize that this
is a double-density disk and to perform whatever internal magic is
necessary to read the disk properly? Or is this an issue of hardware?
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage mputers
]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]
1:16 p.m.
On Sun, 19 Dec 2004, Bill Girnius wrote:
Is it possible it's an 8 sector disk before dos
2.25?
No, and you still owe me $10.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
10:36 p.m.
A:) why is it not possible
B:) Why do I owe you ten dollars
C:) If I do, why on earth would you post it publically and not just ask or
remind me?
----- Original Message -----
From: "Vintage Computer Festival" <vcf(a)siconic.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Sunday, December 19, 2004 1:16 PM
Subject: Re: Problems reading older disk on newer drive
On Sun, 19 Dec 2004, Bill Girnius wrote:
Is it possible it's an 8 sector disk before
dos 2.25?
No, and you still owe me $10.
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger
http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage
mputers ]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]
20 Dec
20 Dec
6:20 a.m.
On Sun, 19 Dec 2004, Bill Girnius wrote:
A:) why is it not possible
Because.
B:) Why do I owe you ten dollars
Because you bought something from me a long time ago and never paid.
C:) If I do, why on earth would you post it publically
and not just ask or
remind me?
Because every time I e-mailed you about it you ignored me.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
6:30 a.m.
Maybe you should email me privately about it with your address, what I
bought, and I can pay you because I have no idea what you are talking about.
----- Original Message -----
From: "Vintage Computer Festival" <vcf(a)siconic.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Monday, December 20, 2004 6:20 AM
Subject: Re: Problems reading older disk on newer drive
On Sun, 19 Dec 2004, Bill Girnius wrote:
A:) why is it not possible
Because.
B:) Why do I owe you ten dollars
Because you bought something from me a long time ago and never paid.
C:) If I do, why on earth would you post it
publically and not just ask
or
remind me?
Because every time I e-mailed you about it you ignored me.
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger
http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage
mputers ]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]
6:26 p.m.
Well, Sam and I got it figured out and taken care of. Neither one of us is
really sure what happend, but it seems i did owe him ten dollars, how he got
missed I'm not sure, and paid him with interest, we might even become
friends.
----- Original Message -----
From: "Vintage Computer Festival" <vcf(a)siconic.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Sunday, December 19, 2004 1:16 PM
Subject: Re: Problems reading older disk on newer drive
On Sun, 19 Dec 2004, Bill Girnius wrote:
Is it possible it's an 8 sector disk before
dos 2.25?
No, and you still owe me $10.
--
Sellam Ismail Vintage Computer
Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger
http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage
mputers ]
[ and academia at www.VintageTech.com || at
http://marketplace.vintage.org ]
9:43 p.m.
On Mon, 20 Dec 2004, Bill Girnius wrote:
Well, Sam and I got it figured out and taken care of.
Neither one of us is
really sure what happend, but it seems i did owe him ten dollars, how he got
missed I'm not sure, and paid him with interest, we might even become
friends.
Yes, thanks.
And "Sam" is an anachronism these days ;)
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
7317
days inactive
7319
days old
14 comments
5 participants
participants (5)
-
nico＠farumdata.dk -
pkoning＠equallogic.com -
thedm＠sunflower.com -
tomj＠wps.com -
vcf＠siconic.com