On Sat, 07 Jun 2008 12:19:58 -0400, mm <NOPSAMmm2005@bigfoot.com> put
finger to keyboard and composed:
>On Sat, 07 Jun 2008 15:27:04 +1000, Franc Zabkar
><fzabkar@iinternode.on.net> wrote:
>
>>On Sat, 07 Jun 2008 00:14:35 -0400, mm <NOPSAMmm2005@bigfoot.com> put
>>finger to keyboard and composed:
>>
>>>A friend gave me a 5 1/4 inch floppy that she wants to retrieve some
>>>data from.
>>>Current attempts to read the disk with a high density drive have given
>>>nothing but low-values, zeroes, including when using Norton Diskedit
>>>(where I only read 12 clusters) and RESQFLPY, with which I copied the
>>>entire floppy and got a file 368,640 bytes long. When I looked at the
>>>copy on the hard drive, using Notepad+, it was entirely zeroes.
>>The documentation for RESQFLPY states that defective sectors are
>>identified during the "rescue" process. Were there any?
>
>Yes, it said that all 720 sectors were defective. That seems
>unlikely, but not impossible, but it also tended to make me think my
>drive was the problem.
>>If DOS doesn't complain, then the diskette probably really has been
>>zero-filled.
>
>And if it does complain?
If it doesn't complain, it means that the contents of that sector are
error free, ie the computed CRC matches the retrieved CRC.
If it does complain, then the sector is unreadable, or your floppy
drive or controller are bad or incompatible, or your diskette is
magnetically blank, or your diskette has been formatted with an
incompatible format.
Was the diskette used in a PC, or some other machine like a Commodore,
Apple II, or a CP/M machine? For example, I have several 5.25"
diskettes that were used in an old Sanyo CPM word processor. These
can't be read by DOS on my old 486 box (Abort, Retry, Fail errors),
but I can retrieve all the contents using a program called Alien. BTW,
I can't even see the boot sector with Debug.exe, so it looks like a
physical format issue.
If your diskette is a foreign format, then try Sydex's 22disk and/or
Anadisk. AIUI, Anadisk can analyse the physical format of your
diskettes and 22disk can do two-way file transfer between DOS and
CP/M.
>>- Franc Zabkar
>
>The advantage of RESQFLPY was that it doesn't abort if it comes across
>a bad sector. It just goes to the next sector. However it thinks
>every sector is bad and that doesn't seem likely.
Hopefully it leaves you with a log that tells you which sectors were
bad and which were really zero-filled.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
On Sun, 08 Jun 2008 09:06:21 +1000, Franc Zabkar
<fzabkar@iinternode.on.net> wrote:
>
>Was the diskette used in a PC, or some other machine like a Commodore,
>Apple II, or a CP/M machine? For example, I have several 5.25"
I'll have to ask about that. She should have mentioned that, but it's
easy to forget even important stuff like that.
>diskettes that were used in an old Sanyo CPM word processor. These
>can't be read by DOS on my old 486 box (Abort, Retry, Fail errors),
>but I can retrieve all the contents using a program called Alien. BTW,
>I can't even see the boot sector with Debug.exe, so it looks like a
>physical format issue.
>
>If your diskette is a foreign format, then try Sydex's 22disk and/or
>Anadisk. AIUI, Anadisk can analyse the physical format of your
>diskettes
I want to try all the recommended programs, but so far, I've just
gotten Anadisk, and it's version 2.07 from 1992. It can create a disk
with user-defined sectors and stuff, but everything else gives the
message, Not ready reading drive B. I have to find a more recent
version.
>and 22disk can do two-way file transfer between DOS and
>CP/M.
>>>- Franc Zabkar
>>
>>The advantage of RESQFLPY was that it doesn't abort if it comes across
>>a bad sector. It just goes to the next sector. However it thinks
>>every sector is bad and that doesn't seem likely.
>
>Hopefully it leaves you with a log that tells you which sectors were
>bad and which were really zero-filled.
It didn't, but maybe that's because it thought every sector was bad.
>- Franc Zabkar
>--
>Please remove one 'i' from my address when replying by email.
If you are inclined to email me
for some reason, remove NOPSAM :-)
On Sat, 07 Jun 2008 22:58:37 -0400, mm <NOPSAMmm2005@bigfoot.com> put
finger to keyboard and composed:
>On Sun, 08 Jun 2008 09:06:21 +1000, Franc Zabkar
><fzabkar@iinternode.on.net> wrote:
>>If your diskette is a foreign format, then try Sydex's 22disk and/or
>>Anadisk. AIUI, Anadisk can analyse the physical format of your
>>diskettes
>
>I want to try all the recommended programs, but so far, I've just
>gotten Anadisk, and it's version 2.07 from 1992. It can create a disk
>with user-defined sectors and stuff, but everything else gives the
>message, Not ready reading drive B. I have to find a more recent
>version.
I just tried version 2.07 on some 20-year-old 5.25" Nashua CP/M
diskettes. One was a DSQD 96TPI MD2F, the other a DSDD 96TPI MD2F.
Both were detected as double density with a sector size of 256 bytes
(MS uses 512 bytes), 16 sectors per track and 80 tracks per side. I
was also able to detect a DD 48TPI DOS diskette.
>>>The advantage of RESQFLPY was that it doesn't abort if it comes across
>>>a bad sector. It just goes to the next sector. However it thinks
>>>every sector is bad and that doesn't seem likely.
>>
>>Hopefully it leaves you with a log that tells you which sectors were
>>bad and which were really zero-filled.
>
>It didn't, but maybe that's because it thought every sector was bad.
I would think that in the absence of a log, one better way to flag a
bad sector would be to write "BAD" repetitively all over the relevant
section of the image file.
BTW, I always check my discs for physical damage by rotating the disc
inside the jacket and looking for scratches or signs of mould. If
mould clogs your R/W heads, then you risk damaging other diskettes.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
On 7 Jun 2008 18:08:31 GMT, Arno Wagner <me@privacy.net> wrote:
>As there are no 5" drives, I think that is exactly what you want.
You can probably buy one used on eBay.
>Note that you can still attack that old floppy to any modern
>mainboard that has a floppy controller.
But, before you give up, you should try to clean the drive heads. They
may have years and years of gunk on them.
>
>>>AFAIK the controller handles it. THe problem is that XP or Vista
>>>does not. Read them with Linux.
AFAIK 3 1/2" formats are the same as 5 1/4" formats, by design.
But it's also possible that the floppy disk itself has experienced
some deterioration so that it is no longer readable.
Previously Andrew Hamilton <Ahamilton90900@yahoo.com> wrote:
> On 7 Jun 2008 18:08:31 GMT, Arno Wagner <me@privacy.net> wrote:
>>As there are no 5" drives, I think that is exactly what you want.
> You can probably buy one used on eBay.
>>Note that you can still attack that old floppy to any modern
>>mainboard that has a floppy controller.
> But, before you give up, you should try to clean the drive heads. They
> may have years and years of gunk on them.
>>
>>>>AFAIK the controller handles it. THe problem is that XP or Vista
>>>>does not. Read them with Linux.
> AFAIK 3 1/2" formats are the same as 5 1/4" formats, by design.
They are similar, some are the same. Howerver 5.25" HD
drives rotate at 360rpm instead of the 300rpm that DD
and 3.5" drives rotate. All not a problen, but MS dropped
support for some older format some time ago.
On Sat, 7 Jun 2008 03:48:44 -0700 (PDT), "mscotgrove@aol.com"
<mscotgrove@aol.com> put finger to keyboard and composed:
>HD 5.25" drives were dual speed as the 1.2MB disks span at 360 rpm,
>and not 300 rpm.
If you mean that HD drives would spin at 360RPM for 1.2MB diskettes
and at 300RPM for 360KB diskettes, then I don't believe this is true
for all HD drives, if any. My copy of IBM's original technical
reference for the PC AT states that the High Capacity Diskette Drive
had a rotational speed of 360RPM. There is a circuit diagram of the
main FDD PCB, but not for the motor control board. Nevertheless there
appears to be only one signal going to the motor PCB and that is Motor
ON.
>They are also 96tpi rather than 48tpi.
According to IBM's original technical reference for the PC AT, HD
5.25" drives were 96TPI. Confusingly, the manual also lists *exactly*
the same specs for DD drives as for HD drives (eg 1.2MB formatted
capacity, 600-650 Oersted media coercivity), even though it states
that the DD drive is limited to 320/360KB capacity. <shrug> I suspect
this is an error.
>The HD 5.25" disk emulates the DD 8" disk.
A 360KB formatted capacity is achieved with 2 sides, 40 tracks per
side, 9 sectors per track. There are 512 data bytes per sector.
A 1.2MB formatted capacity is achieved with 2 sides, 80 tracks per
side, 15 sectors per track.
A 720KB formatted capacity (3.5" drive) is achieved with 2 sides, 80
tracks per side, 9 sectors per track.
A 1.44MB formatted capacity is achieved with 2 sides, 80 tracks per
side, 18 sectors per track.
>When I last 'played' with floppy disks some years ago I do remember
>that some modern disk controllers did not handle all old densities.
>It is possible you have an issue with the controller rather than the
>physical drive.
>
>With the correct controller, all HD drives will read DD disks
>
>Michael
A 720KB 3.5" diskette rotating at 300RPM would produce a data rate of
2700 sectors per minute. A 360KB diskette rotating at 360RPM would
produce a data rate of 3240 sectors per minute. A 1.44MB diskette
rotating at 300RPM would produce a data rate of 5400 sectors per
minute. Therefore it seems to me that a controller that can read a
720KB 3.5" diskette should easily handle a 360KB 5.25" diskette, if
the issue is the range of the PLL/VCO in the clock/data separator.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
On Jun 9, 11:10*pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> On Sat, 7 Jun 2008 03:48:44 -0700 (PDT), "mscotgr...@aol.com"
> <mscotgr...@aol.com> put finger to keyboard and composed:
>
> >HD 5.25" drives were dual speed as the 1.2MB disks span at 360 rpm,
> >and not 300 rpm. *
>
> If you mean that HD drives would spin at 360RPM for 1.2MB diskettes
> and at 300RPM for 360KB diskettes, then I don't believe this is true
> for all HD drives, if any. My copy of IBM's original technical
> reference for the PC AT states that the High Capacity Diskette Drive
> had a rotational speed of 360RPM. There is a circuit diagram of the
> main FDD PCB, but not for the motor control board. Nevertheless there
> appears to be only one signal going to the motor PCB and that is Motor
> ON.
>
> >They are also 96tpi rather than 48tpi.
>
> According to IBM's original technical reference for the PC AT, HD
> 5.25" drives were 96TPI. Confusingly, the manual also lists *exactly*
> the same specs for DD drives as for HD drives (eg 1.2MB formatted
> capacity, 600-650 Oersted media coercivity), even though it states
> that the DD drive is limited to 320/360KB capacity. <shrug> I suspect
> this is an error.
>
> >The HD 5.25" disk emulates the DD 8" disk.
>
> A 360KB formatted capacity is achieved with 2 sides, 40 tracks per
> side, 9 sectors per track. There are 512 data bytes per sector.
>
> A 1.2MB formatted capacity is achieved with 2 sides, 80 tracks per
> side, 15 sectors per track.
>
> A 720KB formatted capacity (3.5" drive) is achieved with 2 sides, 80
> tracks per side, 9 sectors per track.
>
> A 1.44MB formatted capacity is achieved with 2 sides, 80 tracks per
> side, 18 sectors per track.
>
> >When I last 'played' with floppy disks some years ago I do remember
> >that some modern disk controllers did not handle all old densities.
> >It is possible you have an issue with the controller rather than the
> >physical drive.
>
> >With the correct controller, all HD drives will read DD disks
>
> >Michael
>
> A 720KB 3.5" diskette rotating at 300RPM would produce a data rate of
> 2700 sectors per minute. A 360KB diskette rotating at 360RPM would
> produce a data rate of 3240 sectors per minute. A 1.44MB diskette
> rotating at 300RPM would produce a data rate of 5400 sectors per
> minute. Therefore it seems to me that a controller that can read a
> 720KB 3.5" diskette should easily handle a 360KB 5.25" diskette, if
> the issue is the range of the PLL/VCO in the clock/data separator.
>
> - Franc Zabkar
> --
> Please remove one 'i' from my address when replying by email.
The data rate for 5.25" disks is 125KHz (SD), 250KHz (DD) or 500KHz
(HD)
For 8" it was just 250KHz and 500KHz, always at 360 rpm
The difference in capacity is the speed of rotaion. A faster rotation
with fixed data rate gives a lower capcity
(1.44 * 300) / 360 = 1.20
I seem to remember there is a density line on the disk drive, but I am
currently 7,000 mile from my office an 15 years since I last designed
a floppy disk controller
On Mon, 09 Jun 2008 08:59:26 +1000, Franc Zabkar
<fzabkar@iinternode.on.net> wrote:
>On Sat, 07 Jun 2008 22:58:37 -0400, mm <NOPSAMmm2005@bigfoot.com> put
>finger to keyboard and composed:
>
>>On Sun, 08 Jun 2008 09:06:21 +1000, Franc Zabkar
>><fzabkar@iinternode.on.net> wrote:
>
>>>If your diskette is a foreign format, then try Sydex's 22disk and/or
>>>Anadisk. AIUI, Anadisk can analyse the physical format of your
>>>diskettes
>>
>>I want to try all the recommended programs, but so far, I've just
>>gotten Anadisk, and it's version 2.07 from 1992. It can create a disk
>>with user-defined sectors and stuff, but everything else gives the
>>message, Not ready reading drive B. I have to find a more recent
>>version.
>
>I just tried version 2.07 on some 20-year-old 5.25" Nashua CP/M
>diskettes. One was a DSQD 96TPI MD2F, the other a DSDD 96TPI MD2F.
>Both were detected as double density with a sector size of 256 bytes
>(MS uses 512 bytes), 16 sectors per track and 80 tracks per side. I
>was also able to detect a DD 48TPI DOS diskette.
Hmmm. Then there is still the issue you raised about what OS was used
to write it. I called the owner and to my surprise, she said she had
had a macintosh in her office then, but then her husband called to her
that he had never seen a disk like this, 5.25 floppy, for a macintosh,
and he has used Macintosh at work for 10 or 20 years.
I must have misunderstood. Did Macintosh use the same 5.25" floppies
that PC's did? Could the wife be right?
On the theory she was right, I googled and learned about MacDisk for
Windows, downloaded that, and tried it. When I click on B-drive, it
freezes for a while, and eventually comes back with the reply that the
drive is broken or there is no media in the drive (Drive doesn't
reply). (As an aside, sometimes it comes back with that message but
the computer stays frozen, and one time it unfroze the computer (based
on the ability to move the cursor) . As I said, I've used the drive
for my own floppies in the last two days and it works fine.
I get a message each time I start MacDisk that the ASPI isn't up to
date and to run the ASPI program that was included in the download,
but the date on that is actually a few months older than any of my
other ASPI files, and I don't want to risk installing an older
file(s). Should I look into that further? I can probably
update/backdate ASPI and then undo the damage later.
>>>>The advantage of RESQFLPY was that it doesn't abort if it comes across
>>>>a bad sector. It just goes to the next sector. However it thinks
>>>>every sector is bad and that doesn't seem likely.
>>>
>>>Hopefully it leaves you with a log that tells you which sectors were
>>>bad and which were really zero-filled.
>>
>>It didn't, but maybe that's because it thought every sector was bad.
>
>I would think that in the absence of a log, one better way to flag a
>bad sector would be to write "BAD" repetitively all over the relevant
>section of the image file.
Me too. But it just said Null, according to Notepad+. I wish I still
had 4DOS installed. It has a great, easy to use, List program that
displays data in place just as it is, in hex and ascii. I could find
the disks and reinstall it, but I'm so busy.
>BTW, I always check my discs for physical damage by rotating the disc
>inside the jacket and looking for scratches or signs of mould.
OK, I'm doing that right now. Sometimes it rotates fairly easily, but
much of the time it doesn't want to rotate at all. I can see the disc
bending in the main window**, and I have to let go.
Any chance the disc isn't really spinning and that's causing all of
this? How do I make sure it's spinning when in the drivee? I've had
trouble spinning discs before, and not especially discs that didn't
work. I figured it was just hard to do, or I was no good at doing it.
**By main window, I mean the windows on each side that are shaped like
a running track that surrounds a football field. Not counting the
little round hole it uses just to know the disc is spinning, That's
the only place where it reads data, right? That is, in order to
rotate the disc, when just putting two fingers in the middle hole
wouldn't grip the disc hard enough, I used my thumbs and forefingers
on some of that part of the media that one can see through the center
hole. I left fingerprint oil probably. Is what I did bad?
> If
>mould clogs your R/W heads, then you risk damaging other diskettes.
What I could see of the media looked ok. No mould and no apparent
scratches.
>- Franc Zabkar
If you are inclined to email me
for some reason, remove NOPSAM :-)
On Jun 10, 4:12*am, mm <NOPSAMmm2...@bigfoot.com> wrote:
> On Mon, 09 Jun 2008 08:59:26 +1000, Franc Zabkar
>
>
>
>
>
> <fzab...@iinternode.on.net> wrote:
> >On Sat, 07 Jun 2008 22:58:37 -0400, mm <NOPSAMmm2...@bigfoot.com> put
> >finger to keyboard and composed:
>
> >>On Sun, 08 Jun 2008 09:06:21 +1000, Franc Zabkar
> >><fzab...@iinternode.on.net> wrote:
>
> >>>If your diskette is a foreign format, then try Sydex's 22disk and/or
> >>>Anadisk. AIUI, Anadisk can analyse the physical format of your
> >>>diskettes
>
> >>I want to try all the recommended programs, but so far, I've just
> >>gotten Anadisk, and it's version 2.07 from 1992. *It can create a disk
> >>with user-defined sectors and stuff, but everything else gives the
> >>message, Not ready reading drive B. *I have to find a more recent
> >>version. *
>
> >I just tried version 2.07 on some 20-year-old 5.25" Nashua CP/M
> >diskettes. One was a DSQD 96TPI MD2F, the other a DSDD 96TPI MD2F.
> >Both were detected as double density with a sector size of 256 bytes
> >(MS uses 512 bytes), 16 sectors per track and 80 tracks per side. I
> >was also able to detect a DD 48TPI DOS diskette.
>
> Hmmm. *Then there is still the issue you raised about what OS was used
> to write it. *I called the owner and to my surprise, she said she had
> had a macintosh in her office then, but then her husband called to her
> that he had never seen a disk like this, 5.25 floppy, for a macintosh,
> and he has used Macintosh at work for 10 or 20 years.
>
> I must have misunderstood. *Did Macintosh use the same 5.25" floppies
> that PC's did? *Could the wife be right?
>
> On the theory she was right, I googled and learned about MacDisk for
> Windows, downloaded that, and tried it. *When I click on B-drive, it
> freezes for a while, and eventually comes back with the reply that the
> drive is broken or there is no media in the drive (Drive doesn't
> reply). *(As an aside, sometimes it comes back with that message but
> the computer stays frozen, and one time it unfroze the computer (based
> on the ability to move the cursor) . * As I said, I've used the drive
> for my own floppies in the last two days and it works fine.
>
> I get a message each time I start MacDisk that the ASPI isn't up to
> date and to run the ASPI program that was included in the download,
> but the date on that is actually a few months older than any of my
> other ASPI files, and I don't want to risk installing an older
> file(s). * Should I look into that further? *I can probably
> update/backdate ASPI and then undo the damage later.
>
> >>>>The advantage of RESQFLPY was that it doesn't abort if it comes across
> >>>>a bad sector. *It just goes to the next sector. *However it thinks
> >>>>every sector is bad and that doesn't seem likely.
>
> >>>Hopefully it leaves you with a log that tells you which sectors were
> >>>bad and which were really zero-filled.
>
> >>It didn't, but maybe that's because it thought every sector was bad.
>
> >I would think that in the absence of a log, one better way to flag a
> >bad sector would be to write "BAD" repetitively all over the relevant
> >section of the image file.
>
> Me too. *But it just said Null, according to Notepad+. *I wish I still
> had 4DOS installed. * It has a great, easy to use, List program that
> displays data in place just as it is, in hex and ascii. *I could find
> the disks and reinstall it, but I'm so busy.
>
> >BTW, I always check my discs for physical damage by rotating the disc
> >inside the jacket and looking for scratches or signs of mould.
>
> OK, I'm doing that right now. *Sometimes it rotates fairly easily, but
> much of the time it doesn't want to rotate at all. I can see the disc
> bending in the main window**, and I have to let go.
>
> Any chance the disc isn't really spinning and that's causing all of
> this? * How do I make sure it's spinning when in the drivee? *I've had
> trouble spinning discs before, and not especially discs that didn't
> work. *I figured it was just hard to do, or I was no good at doing it.
>
> **By main window, I mean the windows on each side that are shaped like
> a running track that surrounds a football field. * Not counting the
> little round hole it uses just to know the disc is spinning, That's
> the only place where it reads data, right? * That is, in order to
> rotate the disc, when just putting two fingers in the middle hole
> wouldn't grip the disc hard enough, I used my thumbs and forefingers
> on some of that part of the media that one can see through the center
> hole. *I left fingerprint oil probably. *Is what I did bad?
>
> > If
> >mould clogs your R/W heads, then you risk damaging other diskettes.
>
> What I could see of the media looked ok. *No mould and no apparent
> scratches. *
>
> >- Franc Zabkar
>
> If you are inclined to email me
> for some reason, remove NOPSAM *:-)- Hide quoted text -
>
> - Show quoted text -
I don't think I have ever seen a 5.25" Macintosh disk
I think the original Apple disks had two versions, a 13 and a 16
sector version for the original 5.25" Apple. These were both GCR and
can not be read with any standard PC hardware, hence the reason I was
designing disk controllers 24 years ago. There were then several
logical formats for these disks, Apple DOS, ProDos to name just 2, but
there are more.
On Mon, 9 Jun 2008 18:37:47 -0700 (PDT), "mscotgrove@aol.com"
<mscotgrove@aol.com> put finger to keyboard and composed:
>The data rate for 5.25" disks is 125KHz (SD), 250KHz (DD) or 500KHz
>(HD)
>
>For 8" it was just 250KHz and 500KHz, always at 360 rpm
>
>The difference in capacity is the speed of rotaion. A faster rotation
>with fixed data rate gives a lower capcity
>
>(1.44 * 300) / 360 = 1.20
That's all very well, but if a 360KB DD diskette was written at 250kHz
in a 300RPM DD drive, then the same diskette in a 360RPM HD drive will
be read at 300kHz by the controller. That's because the controller
derives its data clock from the sync bytes just before the sector
data. The HD drive doesn't slow down to 300RPM to match the original
recording speed. At least that is the case for the original IBM PC AT
drives.
>I seem to remember there is a density line on the disk drive, but I am
>currently 7,000 mile from my office an 15 years since I last designed
>a floppy disk controller
>
>Michael
>www.cnwrecovery.com.
There is a "reduced write current" output signal from the FD
controller on pin 2. The HD drive sees this as a Low Density signal
and uses it to reduce the current to the write amps. In the PC AT case
this signal does not appear to have any other function. There is
certainly nothing to vary the speed of the drive. In any case this
signal is not relevant during reading.
I know that some FDDs around that time used pins 2 and 34 (Diskchange)
for different functions, so maybe that could explain your
observations. For example, the Commodore Amiga's pin 34 was a READY
output from the drive and pin 2 was Diskchange.
Re: How to play an old floppy disk. 
Linear Mode
