OT 3.5" floppy question

[Michael A. Terrell]

Mark Zenier wrote:

In article <e6fk77d8j37ctrq3qoqjfvhj9rl1aa1133@4ax.com>,
Tom Biasi <tombiasi@optonline.net> wrote:

Mark, where the hell have you been, I haven't seen a post from you in
years.

The science fiction and shortwave radio groups, mostly. By the time
I get around to the electronics groups, the questions I can answer
already have been...

Sometimes it hard to tell those two groups apart.


--
You can't have a sense of humor, if you have no sense.

 

[David Eather]

On 21/09/2011 1:56 AM, David Eather wrote:

On 21/09/2011 12:06 AM, George Herold wrote:
Hi guys, If you want to direct me to a different group that is fine.
I'm wondering if there is a way to format a HD 3.5" floppy to be only
DD? (HD is high desinity 1.44MB and DD is double density ~720kB, for
those of tender years.) I've been mucking about in DOS trying the
"format a: /Fsize)" command with out success. I also tried putting
some tape on the one corner of the disk to cover up the hole there.

Thanks for any advice,

George H.

Cover the extra hole on the HD floppy disk. All HD floppy DD I have seem
also support DD when feed the appropriate media

Just remembered something that will help. For what your after (format a
DD on HD drive) it helps to bulk erase the disk first (helps with both
HD and DD disks) to remove all that pre-formatted stuff that will just
become noise after formatting.

 

[Jon Kirwan]

On Sat, 24 Sep 2011 12:36:51 +1000, David Eather
<eather@tpg.com.au> wrote:

On 21/09/2011 1:56 AM, David Eather wrote:
On 21/09/2011 12:06 AM, George Herold wrote:
Hi guys, If you want to direct me to a different group that is fine.
I'm wondering if there is a way to format a HD 3.5" floppy to be only
DD? (HD is high desinity 1.44MB and DD is double density ~720kB, for
those of tender years.) I've been mucking about in DOS trying the
"format a: /Fsize)" command with out success. I also tried putting
some tape on the one corner of the disk to cover up the hole there.

Thanks for any advice,

George H.

Cover the extra hole on the HD floppy disk. All HD floppy DD I have seem
also support DD when feed the appropriate media

Just remembered something that will help. For what your after (format a
DD on HD drive) it helps to bulk erase the disk first (helps with both
HD and DD disks) to remove all that pre-formatted stuff that will just
become noise after formatting.

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material. There is a low level
format available in common software, but even that depends
upon some pre-encoded gaps and tracks, I think. The
manufacturers of early media didn't high level format them --
now they do, I think. But they had to do some formatting and
it became almost no problem for them to do the rest before
shipping them out.

The reason I think this is that I had to purchase (and still
have somewhere about my boxes) a special controller board
designed for this purpose. There was a time when you could
buy these, at 10X the usual price of a floppy controller.
They would do everything; custom formats and sector ID
numbering, etc. If you really needed to restore a failed
floppy which was mechanically sound but otherwise unable to
be used for anything, this could (and did) restore them quite
well. (There was a calibration procedure and a great deal of
control which went far, far beyond the usual low level or
high level formatting support options.)

I doubt anything built today for commodity purposes does this
or even supports the capability.

But I'm hanging my memory on the existence of that board and
my recollections using it -- the facts of which I am not in
doubt. And what I very vaguely recall from the documentation
manuals that came with it, about which everything is in doubt
now. So it's more a mosaic which may point up possibilities
to consider.

Jon

 

[John Tserkezis]

Jon Kirwan wrote:

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material. There is a low level
format available in common software, but even that depends
upon some pre-encoded gaps and tracks, I think. The
manufacturers of early media didn't high level format them --
now they do, I think. But they had to do some formatting and
it became almost no problem for them to do the rest before
shipping them out.

While this certainly held true for old MFM/RLL (and that era) hard
drives, it does not apply to floppy drives.

Any format you do on a hard drive is "high level", in that it lays out
the partition table, disk structure and file system. That is, it does
writes data to the disk.
Hard drives come low level formatted from factory, but you could do it
yourself with the right softtware afterwards (with the right drives).
From about the middle of the IDE era, drive complexity had reached the
point that low level formatting became impossible for the end user.
Some drives offered a hardware option to low level format, but these
were few and far between.

I'm guessing this is what you were thinking of.



Floppy drives will "low level" and high level format the disk on one
go. The "quick" format option added later, required the disk to have
already have been low level formatted in the past.
--
System Crash (A)bort (R)etry (T)hrowup

 

[Jon Kirwan]

On Sat, 24 Sep 2011 14:30:52 +1000, John Tserkezis
<jt@techniciansyndrome.org.invalid> wrote:

Jon Kirwan wrote:

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material. There is a low level
format available in common software, but even that depends
upon some pre-encoded gaps and tracks, I think. The
manufacturers of early media didn't high level format them --
now they do, I think. But they had to do some formatting and
it became almost no problem for them to do the rest before
shipping them out.

While this certainly held true for old MFM/RLL (and that era) hard
drives, it does not apply to floppy drives.

Any format you do on a hard drive is "high level", in that it lays out
the partition table, disk structure and file system. That is, it does
writes data to the disk.

This, I think I knew.

Hard drives come low level formatted from factory, but you could do it
yourself with the right softtware afterwards (with the right drives).
From about the middle of the IDE era, drive complexity had reached the
point that low level formatting became impossible for the end user.
Some drives offered a hardware option to low level format, but these
were few and far between.

I'm guessing this is what you were thinking of.

No, I've still got the board here. I'll see if I can find
the docs. It was for floppy drives, not hard drives.

I remember the MFM (40MB and earlier, mostly, though I think
there were some eventually nearing 80MB and perhaps a little
more) and the change to RLL (starting circa 60MB and higher.)

All this _BEFORE_ IDE existed. That's when the "cheap
drives" hit the marketplace.

Floppy drives will "low level" and high level format the disk on one
go. The "quick" format option added later, required the disk to have
already have been low level formatted in the past.

If I can find the manual, I'll post some information from it.
It's probably on a shelf (my walls are coated with book
shelves, and I'm no librarian, so it may not happen tonight
or tomorrow.)

But yes, I could certainly be wrong. Memory is like that.

Jon

 

[Robert Roland]

On Fri, 23 Sep 2011 20:01:46 -0700, Jon Kirwan
<jonk@infinitefactors.org> wrote:

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material.

Not correct. You can safely degauss floppy disks and then reformat
them in an ordinary PC drive.

There is a low level
format available in common software, but even that depends
upon some pre-encoded gaps and tracks, I think.

Floppy drives and very old harddrives use stepper motors to position
the heads. They also include a track 0 detector, so they are able to
position the heads at any absolute position without any magnetic
reference.

Newer harddisks use voice coils to position the heads. Unlike the
stepper, the voice coil cannot be moved to a specific position without
feedback from servo tracks embedded in the disk platters. If you
degauss a voice coil drive, it becomes completely useless.

The reason I think this is that I had to purchase (and still
have somewhere about my boxes) a special controller board
designed for this purpose.

Normal PC floppy controllers are quite primitive, and make several
assumptions about the media and the format. It is not able to access
the disk bit-by-bit. This is why you (usually) can't read a floppy
from a different computer system on such a controller.

There was a time when you could
buy these, at 10X the usual price of a floppy controller.
They would do everything; custom formats and sector ID
numbering, etc.

Such controllers are still sometimes used. One application is to be
able to access disks from antique computer systems on a PC. The
Catweasel is an example of such a controller:
http://en.wikipedia.org/wiki/Individual_Computers_Catweasel
--
RoRo

 

[Jon Kirwan]

On Sat, 24 Sep 2011 10:10:09 +0200, Robert Roland
<fake@ddress.no> wrote:

On Fri, 23 Sep 2011 20:01:46 -0700, Jon Kirwan
jonk@infinitefactors.org> wrote:
I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material.

Not correct. You can safely degauss floppy disks and then reformat
them in an ordinary PC drive.

There is a low level
format available in common software, but even that depends
upon some pre-encoded gaps and tracks, I think.

Floppy drives and very old harddrives use stepper motors to position
the heads. They also include a track 0 detector, so they are able to
position the heads at any absolute position without any magnetic
reference.

Newer harddisks use voice coils to position the heads. Unlike the
stepper, the voice coil cannot be moved to a specific position without
feedback from servo tracks embedded in the disk platters. If you
degauss a voice coil drive, it becomes completely useless.

The reason I think this is that I had to purchase (and still
have somewhere about my boxes) a special controller board
designed for this purpose.

Normal PC floppy controllers are quite primitive, and make several
assumptions about the media and the format. It is not able to access
the disk bit-by-bit. This is why you (usually) can't read a floppy
from a different computer system on such a controller.

There was a time when you could
buy these, at 10X the usual price of a floppy controller.
They would do everything; custom formats and sector ID
numbering, etc.

Such controllers are still sometimes used. One application is to be
able to access disks from antique computer systems on a PC. The
Catweasel is an example of such a controller:
http://en.wikipedia.org/wiki/Individual_Computers_Catweasel

Thanks for the information. It helps. I need to dig up the
documentation I had and see what was really the case. And
maybe unearth the interface board. It's ISA-16 (maybe ISA-8)
and I still have some operating machines here with ISA slots.
So I may be able to learn a little from the effort.

Anyway, thanks for the kick and the information. I'll see if
I can refresh my sad memory.

Jon

 

[John Tserkezis]

Robert Roland wrote:

Newer harddisks use voice coils to position the heads. Unlike the
stepper, the voice coil cannot be moved to a specific position without
feedback from servo tracks embedded in the disk platters. If you
degauss a voice coil drive, it becomes completely useless.

I know I'm nitpicking, but I can't help myself.

Because a drive uses voicecoil technology to position the heads, does
not necessarily mean it MUST use pre-recorded tracks on the magnetic
surface.

I've seen at least one drive that used a shuttered disk, and optics to
count positions from "park", all the way to the other end.
Technically, it would be plausible for the manufacturer to encode LLF
routines into the drive, but that said, I've never seen it.

But true, most if not all drives now exclusively use pre-recorded
tracks to synchronise the head positions, and a degauss would render
that slightly stuffed.
--
Just my two rubber ningis worth.

 

[Jasen Betts]

On 2011-09-20, George Herold <gherold@teachspin.com> wrote:

Thanks Tom, I rumaged around in my stack of old floppies and found a
720K DD one so my need is less urgent. My computer (disk drive) was
able to format it. Is there anyway to force it to format a HD disk as
DD?

Fill the hole with plastic resin or cover it with packing tape on the
underside. this won't work well because the media is harder to
magnetise and the drive will be writing at a too low power level.

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[Jasen Betts]

On 2011-09-24, Jon Kirwan <jonk@infinitefactors.org> wrote:

On Sat, 24 Sep 2011 14:30:52 +1000, John Tserkezis
jt@techniciansyndrome.org.invalid> wrote:


I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material. There is a low level
format available in common software, but even that depends
upon some pre-encoded gaps and tracks, I think.

I've never had that trouble, I used to bulk erase floppy disks using a
loudspeaker magnet assembly and had no trouble reformatting them

the floppy disk drve uses a stepper motor and leadscrew (or sometimes
a metal belt drive) to position the heads so no servo information is
needed to format the disks.

No, I've still got the board here. I'll see if I can find
the docs. It was for floppy drives, not hard drives.

a dedicate floppy formatter could be useful if you had a whole bunch of
disks to recycle...

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[Phil Hobbs]

On 09/24/2011 04:52 AM, John Tserkezis wrote:

Robert Roland wrote:

Newer harddisks use voice coils to position the heads. Unlike the
stepper, the voice coil cannot be moved to a specific position without
feedback from servo tracks embedded in the disk platters. If you
degauss a voice coil drive, it becomes completely useless.

I know I'm nitpicking, but I can't help myself.

Because a drive uses voicecoil technology to position the heads, does
not necessarily mean it MUST use pre-recorded tracks on the magnetic
surface.

I've seen at least one drive that used a shuttered disk, and optics to
count positions from "park", all the way to the other end.
Technically, it would be plausible for the manufacturer to encode LLF
routines into the drive, but that said, I've never seen it.

But true, most if not all drives now exclusively use pre-recorded tracks
to synchronise the head positions, and a degauss would render that
slightly stuffed.

Hard disk head alignment is controlled via servo tracks, which have to
be written very precisely. They used to be written on
interferometrically-controlled spin stands, but nowadays it's done right
in the drive, by the clever application of Newton's laws. (A pal of
mine invented the self-servowriting technique--it made IBM a lot of money.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[Jon Kirwan]

On Sat, 24 Sep 2011 01:21:37 -0700, I wrote:

snip
Anyway, thanks for the kick and the information. I'll see if
I can refresh my sad memory.

Well, "Central Point" is what made it, I think. Vague memory
came back, maybe. Gives me a starting point. I think it was
called an Enhanced or Deluxe Option board or something like
that.

Might be easier to find the docs, now that I have a clue what
I'm looking for.

Jon

 

[Jon Kirwan]

On Tue, 20 Sep 2011 07:06:46 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

Hi guys, If you want to direct me to a different group that is fine.
I'm wondering if there is a way to format a HD 3.5" floppy to be only
DD? (HD is high desinity 1.44MB and DD is double density ~720kB, for
those of tender years.) I've been mucking about in DOS trying the
"format a: /Fsize)" command with out success. I also tried putting
some tape on the one corner of the disk to cover up the hole there.

Thanks for any advice,

George H.

Hey, George. Found this site:

http://retro.icequake.net/dob/index.html#copy

Makes copies for $1 each. Found it while looking for
information on the floppy controller board I used to use.

Jon

 

[David Eather]

On 24/09/2011 1:01 PM, Jon Kirwan wrote:

On Sat, 24 Sep 2011 12:36:51 +1000, David Eather
eather@tpg.com.au> wrote:

On 21/09/2011 1:56 AM, David Eather wrote:
On 21/09/2011 12:06 AM, George Herold wrote:
Hi guys, If you want to direct me to a different group that is fine.
I'm wondering if there is a way to format a HD 3.5" floppy to be only
DD? (HD is high desinity 1.44MB and DD is double density ~720kB, for
those of tender years.) I've been mucking about in DOS trying the
"format a: /Fsize)" command with out success. I also tried putting
some tape on the one corner of the disk to cover up the hole there.

Thanks for any advice,

George H.

Cover the extra hole on the HD floppy disk. All HD floppy DD I have seem
also support DD when feed the appropriate media

Just remembered something that will help. For what your after (format a
DD on HD drive) it helps to bulk erase the disk first (helps with both
HD and DD disks) to remove all that pre-formatted stuff that will just
become noise after formatting.

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material.

Unless that happened (for some reason) after 1995 it most defiantly is
not true. But as other mention the HDD change to voice coil did cause
that problem for them.

 

[Jon Kirwan]

On Mon, 26 Sep 2011 00:44:08 +1000, David Eather
<eather@tpg.com.au> wrote:

On 24/09/2011 1:01 PM, Jon Kirwan wrote:
On Sat, 24 Sep 2011 12:36:51 +1000, David Eather
eather@tpg.com.au> wrote:

On 21/09/2011 1:56 AM, David Eather wrote:
On 21/09/2011 12:06 AM, George Herold wrote:
Hi guys, If you want to direct me to a different group that is fine.
I'm wondering if there is a way to format a HD 3.5" floppy to be only
DD? (HD is high desinity 1.44MB and DD is double density ~720kB, for
those of tender years.) I've been mucking about in DOS trying the
"format a: /Fsize)" command with out success. I also tried putting
some tape on the one corner of the disk to cover up the hole there.

Thanks for any advice,

George H.

Cover the extra hole on the HD floppy disk. All HD floppy DD I have seem
also support DD when feed the appropriate media

Just remembered something that will help. For what your after (format a
DD on HD drive) it helps to bulk erase the disk first (helps with both
HD and DD disks) to remove all that pre-formatted stuff that will just
become noise after formatting.

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material.

Unless that happened (for some reason) after 1995 it most defiantly is
not true. But as other mention the HDD change to voice coil did cause
that problem for them.

Yeah, I may be confusing things. There were times when I
couldn't low level format floppies using Microsoft's DOS
commands to do it. But could, after completely restoring
them using Central Point's software/hardware solution. Since
I'm not a guru on these things (and was wise enough to open
the door to the idea that I didn't know for sure what I was
saying), I'll allow that there was some other reasonable
explanation for my experiences than I imagined.

Jon

 

[David Eather]

On 26/09/2011 2:23 AM, Jon Kirwan wrote:

On Mon, 26 Sep 2011 00:44:08 +1000, David Eather
eather@tpg.com.au> wrote:

On 24/09/2011 1:01 PM, Jon Kirwan wrote:
On Sat, 24 Sep 2011 12:36:51 +1000, David Eather
eather@tpg.com.au> wrote:

On 21/09/2011 1:56 AM, David Eather wrote:
On 21/09/2011 12:06 AM, George Herold wrote:
Hi guys, If you want to direct me to a different group that is fine.
I'm wondering if there is a way to format a HD 3.5" floppy to be only
DD? (HD is high desinity 1.44MB and DD is double density ~720kB, for
those of tender years.) I've been mucking about in DOS trying the
"format a: /Fsize)" command with out success. I also tried putting
some tape on the one corner of the disk to cover up the hole there.

Thanks for any advice,

George H.

Cover the extra hole on the HD floppy disk. All HD floppy DD I have seem
also support DD when feed the appropriate media

Just remembered something that will help. For what your after (format a
DD on HD drive) it helps to bulk erase the disk first (helps with both
HD and DD disks) to remove all that pre-formatted stuff that will just
become noise after formatting.

I vaguely recall that most floppy drive controllers in the
commodity marketplace cannot actually format blank media --
by this, I mean raw magnetic material.

Unless that happened (for some reason) after 1995 it most defiantly is
not true. But as other mention the HDD change to voice coil did cause
that problem for them.

Yeah, I may be confusing things. There were times when I
couldn't low level format floppies using Microsoft's DOS
commands to do it. But could, after completely restoring
them using Central Point's software/hardware solution. Since
I'm not a guru on these things (and was wise enough to open
the door to the idea that I didn't know for sure what I was
saying), I'll allow that there was some other reasonable
explanation for my experiences than I imagined.

Jon

Is it possible that this is a format / quick format thing? There is no
genuine high/low level format on a FDD (at least up to 1995) but they
did introduce a quick format (same command just different switches or it
may have even been been the default on dos 5 ?) - It really only reset
some directory and FAT information. If a FD was bulk erased a quick
format would fail pretty much in the way you describe. I have a FDD - if
it still works and I can find a FD I'll give it a try - info in a few days

 

[Mark Zenier]

In article <lr9s77h9v2cjr60ut4u0ddmprodhlojvbm@4ax.com>,
Jon Kirwan <jonk@infinitefactors.org> wrote:

On Sat, 24 Sep 2011 01:21:37 -0700, I wrote:

snip
Anyway, thanks for the kick and the information. I'll see if
I can refresh my sad memory.

Well, "Central Point" is what made it, I think. Vague memory
came back, maybe. Gives me a starting point. I think it was
called an Enhanced or Deluxe Option board or something like
that.

Might be easier to find the docs, now that I have a clue what
I'm looking for.

I think that's might be one of those special cards that could
read Macintosh (and Commodore?) disks. There were at least two
different companies that made them.

Mark Zenier mzenier@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)

 

[Jasen Betts]

On 2011-09-25, Jon Kirwan <jonk@infinitefactors.org> wrote:

On Mon, 26 Sep 2011 00:44:08 +1000, David Eather
eather@tpg.com.au> wrote:


Unless that happened (for some reason) after 1995 it most defiantly is
not true. But as other mention the HDD change to voice coil did cause
that problem for them.

ms-doe 5(?) had a feature where a corrupted boot sector could stop format
from working. ther ewas some command-line override IIRC.


--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[Jon Kirwan]

On 27 Sep 2011 11:10:28 GMT, Jasen Betts <jasen@xnet.co.nz>
wrote:

On 2011-09-25, Jon Kirwan <jonk@infinitefactors.org> wrote:
On Mon, 26 Sep 2011 00:44:08 +1000, David Eather
eather@tpg.com.au> wrote:


Unless that happened (for some reason) after 1995 it most defiantly is
not true. But as other mention the HDD change to voice coil did cause
that problem for them.

ms-doe 5(?) had a feature where a corrupted boot sector could stop format
from working. ther ewas some command-line override IIRC.

That wasn't my problem. There was a switch option for that
on hard disks, at least. I had used it, on occasion. But
hard disks supported partitioning. I don't recall floppies
being partitioned.

Jon

 

[Jon Kirwan]

On Mon, 26 Sep 2011 18:38:24 GMT, mzenier@eskimo.com (Mark
Zenier) wrote:

In article <lr9s77h9v2cjr60ut4u0ddmprodhlojvbm@4ax.com>,
Jon Kirwan <jonk@infinitefactors.org> wrote:
On Sat, 24 Sep 2011 01:21:37 -0700, I wrote:

snip
Anyway, thanks for the kick and the information. I'll see if
I can refresh my sad memory.

Well, "Central Point" is what made it, I think. Vague memory
came back, maybe. Gives me a starting point. I think it was
called an Enhanced or Deluxe Option board or something like
that.

Might be easier to find the docs, now that I have a clue what
I'm looking for.

I think that's might be one of those special cards that could
read Macintosh (and Commodore?) disks. There were at least two
different companies that made them.

I may not remember much accurately about the board, right
now, but I do know I didn't buy it for that purpose.

Jon