What type of 5 1/4  floppy disks can be used with the 64/128?
Where can i get some from in the UK?

Regards

Graham

Graham Prout wrote:
|What type of 5 1/4  floppy disks can be used with the 64/128?
|Where can i get some from in the UK?

The C-64 usually goes with a 1541 disk drive, which can use the
following unformatted 5.25 inch diskettes:

    SS/SD
    SS/DD
    DS/DD

but only one side will work.  If you have the misfortune of having
to reformat a diskette formatted on a PC disk drive, the r/w head
of that disk drive delivers magnetic flux deeper into the medium
than the 1541 disk drive does.  That only means that you need to
reformat the diskette on a 1541 several times to undo the problem
that the PC disk drive has caused you.  -The magnetic flux that a
r/w head delivers to the diskette is measured against the 1541's
internal clock signal, and a single sweep may not be enough to
deal with the unnecessarily high magnetic flux that a PC disk drive
delivers to a diskette.  If you are dealing with a PC diskette that
simply "does not seem to take" just have the 1541 disk drive do its
format for a longer period of time.  (Don't use a fast nybbler unless
you wrote the nybbling program yourself, and know how to modify the
code to enable multiple sweeps over the disk, over and over again.)
Finally, the magnetic "inductance" of a diskette is the opposite of
its "reluctance."  You can increase the inductance by warming the
diskette up in a toaster oven (very carefully - you do NOT want to
cook the poor thing!).  Try raising it up to 150 degrees - no hotter
than leaving it on a windowsill in direct sunlight on a rather hot
day for a few hours.

That said, you should be able to use an unformatted HD diskette
if you are willing to format it 2 or 3 times, first.  As for hard
sectored diskettes with a bunch of timing holes in them, try to stay
away from those altogther.

Finally, if your 5.25 inch diskette is used, there is a possibility
it is dirty.  Save those diskettes until you feel like opening them
up, taking the medium out and rinsing them, and then re-inserting
them in a brand new 'sleeve.'  If you don't have any brand new
'sleeves' you are going to have to sit down and make some out of
paper and scissors.  It goes without saying that you do all of this
with very clean hands.

|If you are dealing with a PC diskette that simply "does not seem to
|take" just have the 1541 disk drive do its format for a longer period
|of time.  (Don't use a fast nybbler unless you wrote the nybbling
|program yourself, and know how to modify the code to enable multiple
|sweeps over the disk, over and over again.)

I have used diskettes formatted on a PC disk drive, but I had to format
the diskette several times before it would take.

|Finally, the magnetic "inductance" of a diskette is the opposite of
|its "reluctance."

Whoops, I meant, 'admittance.'  heh

|You can increase the inductance by warming the diskette up in a toaster
|oven (very carefully - you do NOT want to cook the poor thing!).  Try
|raising it up to 150 degrees - no hotter than leaving it on a windowsill
|in direct sunlight on a rather hot day for a few hours.

On a hot sunny day, you could also leave it on the dashboard of your
car for four or five hours, and then take it out while it is still
warm, put it in your disk drive and format it then.  The heat causes-
the ferric oxide particles in the disk to vibrate.  This miniscule,
back-and-forth vibratory motion seems to randomize the magnetic
states of the particles at the molecular level.

The above discussion relates to single and double density mediums.

If you are thinking of high density diskettes that have been made
to undergo a PC format, consider the following paragraphs.

|That said, you should be able to use an unformatted HD diskette
|if you are willing to format it 2 or 3 times, first.  As for hard
|sectored diskettes with a bunch of timing holes in them, try to stay
|away from those altogther.
|
|Finally, if your 5.25 inch diskette is used, there is a possibility
|it is dirty.

Put them aside and worry about them later.  You don't want to ruin
your r/w head.  But if these dirty diskettes are all you have, then
you don't have much choice.

|Save those diskettes until you feel like opening them up, taking the
|medium out and rinsing them, and then re-inserting them in a brand new
|'sleeve.'  If you don't have any brand new 'sleeves' you are going
|to have to sit down and make some out of paper and scissors.  It goes
|without saying that you do all of this with very clean hands.

Where there's a will, there's a way.

On Sun, 4 Apr 2004, Graham Prout wrote:

> What type of 5 1/4  floppy disks can be used with the 64/128?
> Where can i get some from in the UK?

	Contact Allan Bairstow of Commodore Scene magazine
(allan.bairstow(at)btopenworld.com).  He may have some to sell.  Also
Shaun Bebbington (ramlink(at)aol.com) can give you contact info for the
Trading Post, which is up in North England.

					Truly,
					Robert Bernardo
					Fresno Commodore User Group
					http://videocam.net.au/fcug

This brings up another question I have. I received via eBay a set of blank 
floppies of the "Fuji Film" variety. They are color-coded, i.e. red, 
blue, tan, green and grey. 

Unfortunately, they are MD2HD diskettes (96 TPI). They will format for 
awhile, then the C-128's 1571 gives up, displaying:

?BAD DISK ERROR
READY.

Any ideas? Are these disks formattable?

Sincerely,

Paul Allen Panks
dunric@yahoo.com
Phoenix, AZ  USA

"Paul Allen Panks" <panks@sdf.lonestar.org> wrote ...

> This brings up another question I have. I received via eBay a set of blank
> floppies of the "Fuji Film" variety. They are color-coded, i.e. red,
> blue, tan, green and grey.
>
> Unfortunately, they are MD2HD diskettes (96 TPI). They will format for
> awhile, then the C-128's 1571 gives up, displaying:
>
> ?BAD DISK ERROR
> READY.
>
> Any ideas? Are these disks formattable?

Sorry, but HD disks are either not reliable when used with a 1571, or will
not work at all.  They should work OK with a High Density disk drive, which
the 1571 is not.
-- 
Best regards,

Sam Gillett

Change is inevitable,
except from vending machines!

Paul Allen Panks wrote:
|This brings up another question I have. I received via eBay a set of blank
|floppies of the "Fuji Film" variety. They are color-coded, i.e. red,
|blue, tan, green and grey.
|
|Unfortunately, they are MD2HD diskettes (96 TPI). They will format for
|awhile, then the C-128's 1571 gives up, displaying:
|
|?BAD DISK ERROR
|READY.
|
|Any ideas? Are these disks formattable?

Don't use a 1571 to format them, use a 1541 instead.

On Mon, 5 Apr 2004, Sam Gillett wrote:
|Sorry, but HD disks are either not reliable when used with a 1571, or will
|not work at all.

That is not completely correct, as it is the damnable 96 tracks per inch
pre-format that is the true culprit in confounding the 1571, which, when
it comes time to format the diskette, looks for something that looks
like a "pre-format" and then - on seeing something like that - that is,
something that comes pretty darn close to an MFM format, jumps ahead of
itself in an attempt to take a shortcut, only to discover that the disk
is laid out significantly differently from what it expects.

If he gets rid of the 96 tracks per inch format, as with a conventional
pizza oven or toaster oven, and warms it up, a 'normal' 1541 style format
can be imposed, and the diskette will work fairly well for a one-time
(write once, read mostly) format.

|They should work OK with a High Density disk drive, which
|the 1571 is not.

The high density relates to the high concentration of ferric oxide in
the disk.  As such, it is what is generally known as a "high-coercivity"
medium.  High-coercivity means you need a lot of magnetic flux to
overcome the reluctance of the medium.  That said, you can still use
those kinds of disks, but essentially as a "write once, read mostly"
disk.  The 1541 read/write head does not project as strong a magnetic
field as a PC disk drive, sufficient to magnetize all the ferric oxide
particles present in the footprint.

Matthew,

Will formatting them via Star Commander and a 1541 attached to the 
Parallel port of the PC work?

Sincerely,

Paul Allen Panks
dunric@yahoo.com
Phoenix, AZ  USA

Paul Allen Panks wrote:
|Matthew,
|
|Will formatting them via Star Commander and a 1541 attached to the
|Parallel port of the PC work?

An interesting question.  I'd give it a shot, and try formatting
a few dozen of them that way, and see how many of them still have
errors.

How many 1541 disk drives do you have?  You might want to try your
Star Commander with a variety of 1541 drives to see which ones are
still in good condition.

|Matthew,
|
|Will formatting them via Star Commander and a 1541 attached to the
|Parallel port of the PC work?

You want the diskettes to be warmed up.  Body temperature is only
98.6 degrees, and that isn't as good as 140 degrees.  But the boiling
point of water is way too high, so don't get them that hot.  Remember
to keep the disk drive at room temperature because your drive should
not be raised to that kind of a temperature.

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote ...

[mis-information snipped]

Nothing left to reply to!
-- 
Best regards,

Sam Gillett

It looks like your gene
pool could use a filter!

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote ...

> Paul Allen Panks wrote:
> |This brings up another question I have. I received via eBay a set of blank
> |floppies of the "Fuji Film" variety. They are color-coded, i.e. red,
> |blue, tan, green and grey.
> |
> |Unfortunately, they are MD2HD diskettes (96 TPI). They will format for
> |awhile, then the C-128's 1571 gives up, displaying:
> |
> |?BAD DISK ERROR
> |READY.
> |
> |Any ideas? Are these disks formattable?
>
> Don't use a 1571 to format them, use a 1541 instead.

Matthew, you have been around the Commodore scene long enough to know that HD
(High Density) disks should not be used with the 1541 either.

DD (Double Density) disks should be used with both the 1541 and 1571.  The
1541 can also use SD (Single Density) disks.  Offhand, I don't remember if
Commodore specified SD disks as OK for use with the 1571 or not.
-- 
Best regards,

Sam Gillett

It looks like your gene
pool could use a filter!

If anybody wants it, I've got a bulk demagnatizer that was sold in the 
early 80's from Radio Shack. It should be good to zap the diskettes in 
case you're afraid of burning them. Don't know what's a decent price so 
I'll say $15.00 + s/h from zip 27513. No overseas. Please email responses.


Matthew Montchalin wrote:

> |Matthew,
> |
> |Will formatting them via Star Commander and a 1541 attached to the
> |Parallel port of the PC work?
> 
> You want the diskettes to be warmed up.  Body temperature is only
> 98.6 degrees, and that isn't as good as 140 degrees.  But the boiling
> point of water is way too high, so don't get them that hot.  Remember
> to keep the disk drive at room temperature because your drive should
> not be raised to that kind of a temperature.
> 

Sam Gillett wrote:
|> |Any ideas? Are these disks formattable?
|>
|> Don't use a 1571 to format them, use a 1541 instead.
|
|Matthew, you have been around the Commodore scene long enough to know
|that HD (High Density) disks should not be used with the 1541 either.

Not for repeated rewritings, but I managed to format some HD diskettes
and fill them up with programs that read out just fine.  Clearly you
wouldn't want a high density disk for a "work" disk that you had to keep
writing stuff back on.  That's why you issue a command at the start of
the day to transfer the entire disk into your 1750 REU (just enter the
command:

   @0,"d:8"

and later on at the end of your day, pass it back to the disk drive with
a command like:

   @0,"u:8"

and if the disk drive starts balking with a flashing red light, simply
reissue the command one more time.  Of course, you would want to install
MAS-128 before you use those kinds of commands.

|DD (Double Density) disks should be used with both the 1541 and 1571.  The
|1541 can also use SD (Single Density) disks.  Offhand, I don't remember if
|Commodore specified SD disks as OK for use with the 1571 or not.

The 1571 can certainly use SD on the first side but my gut feeling is
that you ought to refrain from formatting the other side.

|Clearly you wouldn't want a high density disk for a "work" disk that you
|had to keep writing stuff back on.  That's why you issue a command at
|the start of the day to transfer the entire disk into your 1750 REU
|(just enter the command:
|
|   @0,"d:8"
|
|and later on at the end of your day, pass it back to the disk drive with
|a command like:
|
|   @0,"u:8"
|
|and if the disk drive starts balking with a flashing red light, simply
|reissue the command one more time.

In other words, if the first sixty or seventy files successfully make
it back to the disk drive before the red light starts flashing, and
you cursor up to send the same command a second time, the RAMDOS
resumes the transfer where it left off, after reporting which files
are already there.  Exactly as most of us would prefer.

|Of course, you would want to install MAS-128 before you use those kinds
|of commands.

If you are using a C-128 emulator, there is no way of knowing if a PC
can do that sort of thing.  My gut feeling is that PC emulators cannot,
if my experiences with VICE128 a few years ago are any guide to go by.

"Sam Gillett" <samgillettnospam@diespammermsn.com> wrote in message
news:W25cc.7841$I66.5880@nwrddc03.gnilink.net...
>
> Matthew, you have been around the Commodore scene long enough to know that
HD
> (High Density) disks should not be used with the 1541 either.
>
> DD (Double Density) disks should be used with both the 1541 and 1571.  The
> 1541 can also use SD (Single Density) disks.  Offhand, I don't remember if
> Commodore specified SD disks as OK for use with the 1571 or not.

The problem with High Density is that SO many of them are "Hard Sectored"
and this thing with the two hole in the disk. If you know what I mean but a
High Density "Soft Sector" disk may be formattable.

You know something, since all modern PC's main controllers that handled the
floppy drives. Why don't anyone simply make a microcontroller and attach it
to the 5.25" drive. Hey Maurice,  your FD-2000 handles thouse 3.5" drives.
Wouldn't the FDC (Floppy Disk Controller) in the Controller board -
technically be able to support the 5.25" PC Floppy. The key would be to
"readjust" the DOS ROM. I was thinkin' but don't want to use my ONLY FD-2000
for this.  Anyway, I believe it should be possible since the chip part
itself would generally do all that and would be like any of the other Floppy
Disk Controllers from the 386/486 days (when they were external). They are
also interface over the same cabling on the PC. Hence the cables with both
3.5" & 5.25" drives.

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote in message
news:Pine.LNX.4.44.0404042351260.7768-100000@lab.oregonvos.net...

> In other words, if the first sixty or seventy files successfully make
> it back to the disk drive before the red light starts flashing, and
> you cursor up to send the same command a second time, the RAMDOS
> resumes the transfer where it left off, after reporting which files
> are already there.  Exactly as most of us would prefer.
>
> If you are using a C-128 emulator, there is no way of knowing if a PC
> can do that sort of thing.  My gut feeling is that PC emulators cannot,
> if my experiences with VICE128 a few years ago are any guide to go by.
>

Matthew Montchalin wrote:
|Paul Allen Panks wrote:
||Matthew,
||
||Will formatting them via Star Commander and a 1541 attached to the
||Parallel port of the PC work?
|
|An interesting question.  I'd give it a shot, and try formatting
|a few dozen of them that way, and see how many of them still have
|errors.

When the red light starts blinking, can you find out which tracks
were successfully formatted, and which ones were not?

Do you mean to tell me that *none* of the tracks were formatted?

Is there any way that you can issue a read task to the job queue
to find out if at least one of the tracks was successfully formatted?

What might be the problem, here, is that the outermost part of the
disk was successfully formatted, but as the 1541 r/w head was stepped
inwards toward the inner hub, it started encountering problems.

||Will formatting them via Star Commander and a 1541 attached to the
||Parallel port of the PC work?
|
|You want the diskettes to be warmed up.  Body temperature is only
|98.6 degrees, and that isn't as good as 140 degrees.  But the boiling
|point of water is way too high, so don't get them that hot.  Remember
|to keep the disk drive at room temperature because your drive should
|not be raised to that kind of a temperature.

If the diskettes get 'crispy' you have probably ruined them.  Don't get
them that hot.  I naturally assume you have bought a very large number
of 5.25 inch diskettes 'bulk' and are trying them out, one by one.

I once bought 500 bulk diskettes, and approximately ten percent were
bad.  This will kind of make you laugh, but I became curious why so
many were bad.  -I used a pair of scissors and opened them up, only
to discover that the manufacturer's conveyor belts had to have been
slipping because some of the disk sleeves were packed with two or
three diskettes!

||An interesting question.  I'd give it a shot, and try formatting
||a few dozen of them that way, and see how many of them still have
||errors.
|
|When the red light starts blinking, can you find out which tracks
|were successfully formatted, and which ones were not?
|
|Do you mean to tell me that *none* of the tracks were formatted?
|
|Is there any way that you can issue a read task to the job queue
|to find out if at least one of the tracks was successfully formatted?

You ought to issue a SEEK before you issue a READ.

|This will kind of make you laugh, but I became curious why so many were
|bad.  -I used a pair of scissors and opened them up, only to discover
|that the manufacturer's conveyor belts had to have been slipping because
|some of the disk sleeves were packed with two or three diskettes!

And yet I've never bought a bulk quantity of 3.5 inch disks.

Does anybody know if "production runs" are equally peppered with
poorly manufactured diskettes like those that plague manufacturers
of 5.25 inch disks?

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote in message
news:Pine.LNX.4.44.0404041951460.26744-100000@lab.oregonvos.net...
> On Mon, 5 Apr 2004, Sam Gillett wrote:
> |Sorry, but HD disks are either not reliable when used with a 1571, or
will
> |not work at all.
>
> That is not completely correct, as it is the damnable 96 tracks per inch
> pre-format that is the true culprit in confounding the 1571

No, in fact it is because the write current on HD drives is much higher then
on DD/SD drives and the magnetic medium requires a higher write current for
the information to be recorded properly.

The Commodore drives cannot produce write currents that will reliably record
to HD media.

That is the reason, not the rubbish you posted.

I got specs on the HD disk format and I'll send it to you and Matthew.

BTW Matthew, its 80 tracks even on HD disks and 2 sides. The disk capacity
is based on more sector per track. Higher RPM and higher write current. You
have to mod the mechanism in order to get upto it. Just read below. The tpi
is not so much the concern but big things to look at track bit density, data
frequency & RPM. 1541s use mechanisms for the first 5.25" drives (SS/SD 40
tracks) but the 80 tracks disks can be reformated into a 40 track fairly
easily because the drive mechanism will write one whole track that takes up
the space of two. Every 2 tracks would equal 1 track but also hard sector
disks will screw you every time due to all those holes. Have Soft sector
disks and you can forge the format over.

Also note: We typically use Iron Oxide coated disks not Cobalt coating. This
will have a result and because the heads on the 1541 were not designed for
cobalt oxide coated disks (it can effect the quality of the writing.). When
you consider 300 oresteds is what the 1541 disks were designed for - and the
HD 5.25" disks have 600 oresteds coercivity. If you manage to successfully
install a PC Floppy drive mechanism to the 1541/1571 drive controller than
we might have something to look into. It may be easier to hook the PC Floppy
to the FD-2000 or 1581 drive controller and mod the ROM. The 5.25" HD
Floppies use the same coating as the 3.5" Floppy Disks.

These are roughly correct -

http://www.karbosguide.com/hardware/module4a.htm (graphical browser
recommended and maybe required)
http://pluto.njcc.com/~hjohnson/drive.txt (text, graphical browser not
required but I suggest graphical so you can read both)

Matthew, definitely read them both. The track bit density is significantly
higher on the HD Floppies (HD = High Density in this topic)

A snippet from the second link:
----------------------------------------------------------------------------
----------------------------------------------

Tech Notes on floppy drives
---------------------------

Floppy diskettes: media, tracks, bit density, rotation speed, hard sectors

To respond to questions reading and writing to diskettes under various
combinations
of drives and disk media, one needs the technical facts, some knowledge
about
how diskettes are read and written; and then the actual numbers regarding
standards on various floppy media and drives.

Diskettes spin at some rotational speed under a read/write head. The head is
some distance from the center of rotation so the actual radial speed of
the media, and therefore the density of flux changes or bits per radial inch
of the media, will vary. The innermost track will have the highest physical
density (or lineal density) of bits as the media is moving at the slowest
radial speed.

Data can be corrupted if the tracks are too close together. Some media
support
more data density: that media has "higher coerecivity" than media which
supports less data density.

Data is written by writing a data track with a write head which is followed
by a "tunnel erase" pair of heads to erase data on either side of the data
track. From manufacturer's notes: The "tunnel erase ceramic type [heads
form]
non-recorded areas between each track to avoid crosstalk and increase
interchangability". And, "when writing, the head erases the outer
edges of the track to ensure the data recorded will not exceed
the ..track width". Some information below reports the width of the
data track before and after the tunnel erase.

Data about floppy drives and media
----------------------------------

Here are the hot charts for various drives and formats. Some odd but useful
facts are also reported.

8-inch drives, 77 tracks:
        track bit density, innermost track
                3200-3600 bpi for single density,
                6400-6500 bpi for double density
        (note: index hole in sleeve in different locations for single/double
sided)
        rotation speed 360 RPM
        track density 48 tpi (tracks per inch)
        track width: .012 inches
        track interval (implied): .0208 inches
        data frequency
                250Kbps, FM single density
                500Kbps, MFM double density
        write current reduced when writing to tracks > 43
	media: iron oxide coating, 300 oresteds coercivity all formats
        sleeve material: dilithium/paper matrix

5.25 inch drives, 40 track (early drives 35 track)

        track bit density, innermost track
                2500-2900 bpi for single density,
                5600-5900 bpi for double density
        rotation speed 300 RPM
        track density 48 tpi (tracks per inch)
	head stepper motor angle per step: 3.6 degrees
        capacity 250KB single density (less formatted)
                 500KB single density less formatted)
        track radius from 1.542 inches to 2.250 inches  (maybe 35 track?)
                          1.354 inches to 2.25 inches
        Track width
                before tunnel erase .013 inch
                after erase  .0124 inch (.012, .33mm [.0129 inch] also
reported)
        Track interval .0208 inches
	media: iron oxide coating, 300 oresteds coercivity

5.25 inch drives, 720K DD, 80 track

        track bit density, innermost track
                3000 bpi for single density (SD) FM
                6000 bpi for double density (DD) MFM
        rotation speed 300 RPM
        track density 96 tpi (tracks per inch)
                (some drives 100 tpi, see index at top)
                (double step to create 48tpi 40 track diskettes)
        head stepper motor angle 1.8 degrees
        capacity 500KB single density (less formatted)
                 1MB double density (less formatted)
        data frequency
                125Kbps, FM single density
                250Kbps, MFM double density
        track radius ??? (probably similar to 40 track drives?)
        Track width
                before tunnel erase .0065 inch
                after erase  "to not exceed .006 inch".
                (note: narrower track than 360K drives)
        Track interval (implied): .0104 inches
	media: iron oxide coating, 300 oresteds coercivity

5.25 inch drives, 1.2M HD, 80 track

        (note: for use at 360K or 720K, see previous specs ex. following:
            data frequency vs rotation speed
                   250Kbps, MFM double density at 300RPM (older pre-PC type)
                   300Kbps, MFM double density at 360RPM (newer, IBM PC
type)
        track bit density, innermost track
                9600-9800 bpi for high density MFM
        rotation speed 360 RPM (ex. as noted above)
        data frequency
                ???Kbps, high density
        track density 96 tpi (tracks per inch) (some drives 100 tpi)
	head step angle 1.8 degrees
        Track width: .16 mm (.0063 inch), also .0061 inch
        media: cobalt coating, 600 oresteds coercivity

3.5 inch drives, 720K and 1.44M and 2.88M

	rotation speed: 300 RPM
	track density 134, 135 tpi
	80 tracks per side; IBM MS-DOS sectors per track 9, 18, 36 respectively
	head step angle 1.8 degrees
        data frequency
                250Kbps, MFM double density
                500Kbps, ??? high density
                ???Kbps, ??? 2.88M
	track bit density: 8717 bpi at 720K; 17,434 bpi at 1.44M; 34,848 at 2.88M
	media: cobalt, 665 Oersteds at 720K; 720 Oresteds at 1.44M;
               barium, 1200 at 2.88M
	track width: .115 mm (.0045 inch)

Sources: see sources for "facts..." below.

----------------------------------------------------------------------------
---------------------------------------------------

"Clockmeister" <no-one@nowhere.com> wrote in message
news:4072c9c1$0$56476$c30e37c6@lon-reader.news.telstra.net...

> No, in fact it is because the write current on HD drives is much higher
then
> on DD/SD drives and the magnetic medium requires a higher write current
for
> the information to be recorded properly.
>
> The Commodore drives cannot produce write currents that will reliably
record
> to HD media.
>
> That is the reason, not the rubbish you posted.

On Tue, 6 Apr 2004, Clockmeister wrote:

|> |Sorry, but HD disks are either not reliable when used with a 1571, or
|> |will not work at all.
|>
|> That is not completely correct, as it is the damnable 96 tracks per inch
|> pre-format that is the true culprit in confounding the 1571
|
|No, in fact it is because the write current on HD drives is much higher then
|on DD/SD drives and the magnetic medium requires a higher write current for
|the information to be recorded properly.

What nonsense.  The problem with doing it that way, is that it writes
through to the other side of the disk.  Remember, we are talking about
soft sector, high density, SINGLE sided 5.25 inch disks.

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote in message
news:Pine.LNX.4.44.0404061348170.17216-100000@lab.oregonvos.net...
> On Tue, 6 Apr 2004, Clockmeister wrote:
>
> |> |Sorry, but HD disks are either not reliable when used with a 1571, or
> |> |will not work at all.
> |>
> |> That is not completely correct, as it is the damnable 96 tracks per
inch
> |> pre-format that is the true culprit in confounding the 1571
> |
> |No, in fact it is because the write current on HD drives is much higher
then
> |on DD/SD drives and the magnetic medium requires a higher write current
for
> |the information to be recorded properly.
>
> What nonsense.  The problem with doing it that way, is that it writes
> through to the other side of the disk.  Remember, we are talking about
> soft sector, high density, SINGLE sided 5.25 inch disks.
>

Proving once again that you are clueless. It's well documented, not
something I just made up unlike your makebelieve.

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote in message
news:Pine.LNX.4.44.0404061348170.17216-100000@lab.oregonvos.net...

> What nonsense.  The problem with doing it that way, is that it writes
> through to the other side of the disk.  Remember, we are talking about
> soft sector, high density, SINGLE sided 5.25 inch disks.

Matthew, there is no "singlesided HD" . They are like the 3.5". HD drives
record on BOTH sides of the disk. 2 sides (one directory) x 80 tracks x 15
sectors per track x 512bytes per sector = 1.2 MB. They are either soft
sectored or hard sectored. They are no different then the 3.5" High Density
disks in this respect as the R/W head writes on BOTH sides of the DISK but 1
DIRECTORY. You don't really flip the HD 5.25" disks. Since you have two R/W
heads on working on both sides of the disk.

On Tue, 6 Apr 2004, Rick Balkins wrote:
|> What nonsense.  The problem with doing it that way, is that it writes
|> through to the other side of the disk.  Remember, we are talking about
|> soft sector, high density, SINGLE sided 5.25 inch disks.
|
|Matthew, there is no "singlesided HD" . They are like the 3.5".

If the disk says that it is 'hd' I naturally assume that it is high
density.  If there are not any timing holes, I naturally assume that
it is soft sectored.  If it looks like it measures out to 5.25 inches,
I assume that it is 5.25 inches.

"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote in message
news:Pine.LNX.4.44.0404062018080.7449-100000@lab.oregonvos.net...

> If the disk says that it is 'hd' I naturally assume that it is high
> density.  If there are not any timing holes, I naturally assume that
> it is soft sectored.  If it looks like it measures out to 5.25 inches,
> I assume that it is 5.25 inches.

If there is 11 or 12 holes when you spin the disk looking at the litte area
where the hole it. It's not exactly a timing hole but if there is like 11 or
so holes as you "carefully" rotate the actual disk from the spindle hole in
the center. As you rotate the disk (look at the little hole near the
rectangular/oval-ish shape hole of the outer sleeve of the disk which the
drive's R/W head would be at - which would be towards the right) - just look
for the little holes through the actual floppy disk. If there is like 11 or
12 of them and not just 1 hole then it is likely hard sectored. Basically,
it keeps tracks to a certain size and number of sectors per track. It makes
it difficult to be re-formatted to a different track/sector layout.

Rick Balkins wrote:
|"Matthew Montchalin" <mmontcha@OregonVOS.net> wrote in message
|news:Pine.LNX.4.44.0404062018080.7449-100000@lab.oregonvos.net...
|
|> If the disk says that it is 'hd' I naturally assume that it is high
|> density.  If there are not any timing holes, I naturally assume that
|> it is soft sectored.  If it looks like it measures out to 5.25 inches,
|> I assume that it is 5.25 inches.
|
|If there is 11 or 12 holes when you spin the disk looking at the litte area
|where the hole it. It's not exactly a timing hole but if there is like 11 or
|so holes as you "carefully" rotate the actual disk from the spindle hole in
|the center.

Those are hard sectored, and as I said before, hard sectored disks don't
format.

In article <Pine.LNX.4.44.0404070227340.31839-100000@lab.oregonvos.net>, Matthew Montchalin wrote:
>|where the hole it. It's not exactly a timing hole but if there is like 11 or
>|so holes as you "carefully" rotate the actual disk from the spindle hole in
>|the center.
> 
> Those are hard sectored, and as I said before, hard sectored disks don't
> format.
	On the 1541 they do! Possibly they will also on the older Pet
drives such as the 4040 and the 2031. Personally I would ebay them for
the H89 and Nortstar Horizon users who need hard sectored disks OR ...
	You can always post your info on comp.os.cpm letting the CP/M
users know you want to make a trade for soft sectored media in.

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