1541 double sided double density ?
Luke J Crook
-Luke
Don Judy
>
> Will the 1541 work with double sided, double density disks ?
>
> -Luke
Yes. It's probably best to just use one side with the 1541,
although I have 15 year old disks with the extra notch and
both sides still working.
dj
Glenn P.,
> Will the 1541 work with double sided, double density disks ?
Yes. In fact, that's the Commodore standard.
Axel
"Glenn P.," wrote:
I thought that the standard was single density. Double density disks will work
without problems. Avoid high density disks as they will not work due to
differences in the surface of the disk.
Dave R.
<3BB7301E...@nospam.sprint.ca>:
>I thought that the standard was single density. Double density disks
>will work without problems. Avoid high density disks as they will not
>work due to differences in the surface of the disk.
I thought it was double-density myself, but page 3 of the 1541 user's guide
says to use "standard mini 5 1/4", single sided, single density" media.
You're correct.
SSDD and DSDD work fine though. :)
Axel
"Dave R." wrote:
My 1541 test demo disk from 1986 is SSSD. BTW, I havent ever seen SSSD disk
since then; they are from the CPM era. Mind you, I've seen SSDD 3 1/2 disks,
and have formatted them on both sides without problems. It used to be that if
a 3 1/2 media failed tests it was downgraded to DD and if it was bad on one
side it was downgraded to SD. I wonder if 5.25 disks were treated the same
from a DD perspective and sold as SS or SD.
Glenn P.,
> I thought that the standard was single density.
No. My understanding is that "Single Density" was the first kind of
diskette ever to be introduced, and it was not then called by any
particular name. It is now long since obsolete; the LOWEST density
diskette currently available today is "double density", so called
because when it was first introduced, it was twice the density of
the aforementioned, long obsolete, original "single" density standard;
the "double" part was (naturally enough) a much-touted marketing
label, and it has stuck, even though there's now no longer anything
for it to be "double" the density OF.
--_____ _____
{~._.~} * >>>>>>>> [ "Glenn P.," <C128...@GTI.Net> ] <<<<<<< * {~._.~}
_( Y )_ /| ---------------------------------- |\ _( Y )_
(:_~*~_:) \| "DOOM SLIDE: Will You Be The One To Slide Forever?" |/ (:_~*~_:)
(_)-(_) * --STINE, R. L.: "One Day At Horrorland" * (_)-(_)
Glenn P.,
> ...page 3 of the 1541 user's guide says to use "standard mini
> 5 1/4", single sided, single density" media.
A misprint, surely; single density hasn't been available for years.
Alex Eisenhut
>
> > ...page 3 of the 1541 user's guide says to use "standard mini
> > 5 1/4", single sided, single density" media.
>
> A misprint, surely; single density hasn't been available for years.
>
Um, neither have 1541's.
Yor name
The 1541 uses the 4040 disk format (36 tracks). The 4040 had Shugart Drive
mechanisms.
The thing that gets me though is that if the disks labelled "Double
Density" were truly double density, why didn't the computers that used DD
drives format twice as much information on them?
For instance: The apphel had 160 something kilobytes, why didn't they modify
the DOS to 300 something kilobytes when the DD capable drives were
introduced?
The IBEM had single sided 180K drives and then 360K double-sided. they went
to 1.2 meg drives with a thinner head, but never produced any 720K 5.25 inch
disks.
Amiga (Ah! Amigamisama!) used 800K disks and later 1.6M disks were
available.
I guess what I'm trying to say is why did they put out Double Density disks
and not take advantage of their improved medium?
....
"Close the curtain when you go, I hate the sunlight."
Ruud Baltissen
> disks and not take advantage of their improved medium?
I have my doubts. IMHO 180 KB is using the full capacity. If it wasn't,
there was no need for stretching the gap between the single bits when moving
the head to the inner tracks of a 1541 floppy.
Or was the 1541 also supposed to work with SD???
By moving just one line the elctronics could double the transferrate. The
problem is that the drive cannot handle it as it needs at least about 22
microseconds to handle one byte. The momentary transfer rate is between 26
and 32 uS. Idea: what about doubling the clockspeed and correcting the ROM
where needed?
___
/ __|__
/ / |_/ Groetjes, Ruud
\ \__|_\
\___| http://Ruud.C64.org
Martijn van Buul
> The thing that gets me though is that if the disks labelled "Double
> Density" were truly double density, why didn't the computers that used DD
> drives format twice as much information on them?
Double Density disks are 96 tpi (tracks-per-inch), single density disks are
48tpi. If you'd wanted to use the 'extra features' of DD, you'll need a
80-tracks drive.
> The IBEM had single sided 180K drives and then 360K double-sided. they went
> to 1.2 meg drives with a thinner head, but never produced any 720K 5.25 inch
> disks.
The IBM diskformat is kind of crappy. The innermost tracks are stuffed
to the maximum, the outer tracks waste diskspace. Apple and Commodore used
disks more intelligent, as outer tracks have more sectors than inner tracks.
> Amiga (Ah! Amigamisama!) used 800K disks and later 1.6M disks were
> available.
The Amiga could store 880K (not 800) on a 5.25" DD drive indeed, using
third-party drives (which behaved just like a 3.5" DD drive)
> I guess what I'm trying to say is why did they put out Double Density disks
> and not take advantage of their improved medium?
Commodore did that, to a certain extent. The 8[2]50 and SFD1001 use a
100tpi layout, which unfortunately doesn't match nicely to a standard
disk type. DD is 96 tpi (So you're kind of 'overclocking' your disks),
QD is an overkill. That said, I've been using 96tpi disks in my 8050
and SFD1001 without problems for a while now.
--
Martijn van Buul - Pi...@dohd.org - http://www.stack.nl/~martijnb/
Geek code: G-- - Visit OuterSpace: mud.stack.nl 3333
Kees J. Bot: The sum of CPU power and user brain power is a constant.
Martijn van Buul
> Or was the 1541 also supposed to work with SD???
Yes. The difference between SD and DD is not in the bit density, but in the
number of tracks. This is the reason why you can safely use DD disks in an SD
drive.
HD has the very same track density as DD (96tpi, in case of a 5.25"
disk), but has a higher bit density.
> By moving just one line the elctronics could double the transferrate. The
> problem is that the drive cannot handle it as it needs at least about 22
> microseconds to handle one byte. The momentary transfer rate is between 26
> and 32 uS. Idea: what about doubling the clockspeed and correcting the ROM
> where needed?
Well, you're talking about HD then. If you want to use DD to the max,
you either need a genuine DD diskdrive (hard to find), or a HD diskdrive
in DD mode.
Oh, there *have* been disk formats which used DD drives. Digital made
them, for instance (They used it in their RX50 diskdrive, which was a
freaky double-disk single-sided double-density drive. Stored 400K
per disk (single sided).
Anders Carlsson
> Double Density disks are 96 tpi (tracks-per-inch), single density
> disks are 48tpi. If you'd wanted to use the 'extra features' of DD,
> you'll need a 80-tracks drive.
Hm. I'm rather sure my Maxell (and Goldstar) floppies at home says
"Double Sided, Double Density. 48 tpi". What does that make them,
if SD = 48 and DD = 96?
--
Anders Carlsson
Jim MacKenzie
"Yor name" <Yo...@email.com> wrote in message
news:Xns912D19C2A...@207.217.77.26...
> The thing that gets me though is that if the disks labelled "Double
> Density" were truly double density, why didn't the computers that used DD
> drives format twice as much information on them?
They did.
Single density was originally about 100K. (Atari's 850 drive got 90K on a
single density disk.) Commodore used fancy tricks (GCR encoding, varying
sectors per track) to make this 170K using single density media.
Double density using the old MFM encoding got about 5K per track, or roughly
180K for a 40-track single-sided dusk (360K for double-sided). Commodore
could have used true double density encoding to make their capacity roughly
double, too, but never did.
The 8050 and 8250 (and SFD-1001 drives) used a quad density format that got
quite a high capacity (about 500K on a single-sided disk, a meg on a
double-sided disk).
Jim
Jim MacKenzie
"Martijn van Buul" <pie...@c64.org> wrote in message
news:slrn9rgqvv...@mud.stack.nl...
> > Amiga (Ah! Amigamisama!) used 800K disks and later 1.6M disks were
> > available.
>
> The Amiga could store 880K (not 800) on a 5.25" DD drive indeed, using
> third-party drives (which behaved just like a 3.5" DD drive)
440K actually. 880K on a 3.5" DSDD floppy... I still have my Amiga in the
basement and I owned the A1020 drive (5.25") too.
Jim
djk
"Martijn van Buul" <pie...@c64.org> skrev i meddelandet
news:slrn9rgr7u...@mud.stack.nl...
>
> HD has the very same track density as DD (96tpi, in case of a 5.25"
> disk), but has a higher bit density.
>
tracks/surface".
Are 3M lying then?
/Daniel
MagerValp
MvB> HD has the very same track density as DD (96tpi, in case of a
MvB> 5.25" disk), but has a higher bit density.
DD is 48 TPI, 96 TPI is QD as used by the 8x50 drives.
--
___ . . . . . + . . o
_|___|_ + . + . + . . Per Olofsson, konstnär
o-o . . . o + Mage...@cling.gu.se
- + + . http://www.cling.gu.se/~cl3polof/
Cameron Kaiser
>The IBM diskformat is kind of crappy. The innermost tracks are stuffed
>to the maximum, the outer tracks waste diskspace. Apple and Commodore used
>disks more intelligent, as outer tracks have more sectors than inner tracks.
If you mean the Apple II, I don't think they do. I don't know about the Mac
GCR formats.
--
Cameron Kaiser * cka...@stockholm.ptloma.edu * posting with a Commodore 128
personal page: http://www.armory.com/%7Espectre/
** Computer Workshops: games, productivity software and more for C64/128! **
** http://www.armory.com/%7Espectre/cwi/ **
Don Judy
>
> It occurred to me that Yor name wrote in comp.sys.cbm:
>
> > The thing that gets me though is that if the disks labelled "Double
> > Density" were truly double density, why didn't the computers that used DD
> > drives format twice as much information on them?
>
> Double Density disks are 96 tpi (tracks-per-inch), single density disks are
> 48tpi. If you'd wanted to use the 'extra features' of DD, you'll need a
> 80-tracks drive.
The funny thing is I have a single sided double density 48 tpi
disk from ECHO - mag media. I guess double density doesn't
really have anything to do with whether tpi are 48 or 96, but
was generally the choice of the manufacturer or we just have
a manufacturer or distributor making an inaccurate label.
dj
Don Judy
>
> On Sun., 30-Sep-2001, at 07:45am, "Axel" <Mei...@nospam.sprint.ca> wrote:
>
> > I thought that the standard was single density.
>
> No. My understanding is that "Single Density" was the first kind of
> diskette ever to be introduced, and it was not then called by any
> particular name. It is now long since obsolete;
[snip]
Hi Glenn,
These companies all made or distributed single sided single density
disks. They don't seem rare, at least not here at the homestead. :)
Sentinel
SKC - Actually also says it's 48 tpi.
Elephant Memory Systems
Commodore - well it's single sided and 48 tpi,
doesn't specifically say single density which
would either bear out your "they didn't call
it anything" understanding or place it in the
rare ss-dd 48tpi category, which also is possible
as I have one from ECHO/Mag Media.
Commodore did say
Media:
Diskettes Standard mini 5 1/4", single sided,
single density
in the 1541 manual, which at least indicates a period
of time when it was deemed necessary by someone to
distinguish between single and double density as this
is, after all, an ad hoc world. In light of the above
my understanding would be that it's not a typo in the
manual.
dj
Ville Jouppi
wrote:
880k too. The 1020 indeed was only 40 track, but there were several third
party 80 track 5.25" external drives that wrote the full 880k onto a disk,
making them substitutes for 3.5" drives. Very nice for those who had closets
full of 5.25" floppies.
Hmm, why are 3.5" disks floppy disks in the English language? They don't
really flop do they?
In Finnish, 8" and 5.25" disks are floppies and 3.5" disks are "hard bread"..
Can't really be bothered to find a good word for that in English now, sorry.
:-) 2.5" disks were called "cookies" at some point in time, but I haven't seen
those outside the early digital cameras of the 1990s..
--
CBM, Amiga and PEZ-nut, Scout, Glider pilot, Administrator
Email: vjo...@sci.fi, URL: http://www.sci.fi/~vjouppi/
GSM: +358-40-5679999, IRCNet: Jope
Arabuusimiehet World Domination
Ville Jouppi
>The 1541 uses the 4040 disk format (36 tracks). The 4040 had Shugart Drive
>mechanisms.
Was it really Shugart? The last time I remember opening my 4040, it had the
bare mechanisms and commodore custom boards for digital and analogue. Just
like the 1541.
>Amiga (Ah! Amigamisama!) used 800K disks and later 1.6M disks were
>available.
To nitpick here, it's 880k formatted.. 80k more than the mac :^)
Axel
regards to disk density, although it is quoted on every floppy disk as some
measure of its capacity. Its likely marketing similar to Sale : PC computer
with case and power supply.
The recording qualities of a floppy disk is only proportional to the magnetic
grains on the disk surface itself. If you did this simple calculation, you
could amaze yourself with how many tracks could be put on a disk surface.
Using MFM, you can lay approximately 6500 bytes on one track, using FM, which
approximates to one half the recorded encoding, you could lay 3250 bytes per
track. FM was used on single density disks.
The inner most track lies approximately 1 inch from the center of a 5.25" disk,
thus a track is approximately 3.14 inches in length.
This works out to 1035 bytes per inch at maximum recording density.
Provided that the head positioning mechanism were extremely accurate and needed
a track that was only 1 byte wide, and tunnel erasing occured on either side of
the head and never overlapped, you could have 1035/3 = 345 tracks per inch.
Understandibly, the floppy head, positioning mechanism, and seating mechanism is
not accurate. You should see that the 48, 96, 100 tpi measure is not really
applicable. Its the quality of the drive makes all the difference with
recording on the disk.
Yor name
>>The 1541 uses the 4040 disk format (36 tracks). The 4040 had Shugart
>>Drive mechanisms.
>
> Was it really Shugart? The last time I remember opening my 4040, it had
> the bare mechanisms and commodore custom boards for digital and
> analogue. Just like the 1541.
Okay, you have me on this one. 8-)
I've only seen one 4040 in my life. I got to examine the internals. It
could have been an Alps mechanism inside. Still the same 36 track hardware
limitation though. Also, this was over 18 years ago.
I thought that at one time the Shugart company made half-height 5.25 drives.
Could be wrong here as well. I did have an original Shugart drive
somewhere, it probably got lost in the all the moves I've made in my life.
Paul Foerster
> In Finnish, 8" and 5.25" disks are floppies and 3.5" disks are "hard bread"..
> Can't really be bothered to find a good word for that in English now, sorry.
> :-)
... how about Smörebröd? ;-) SCNR.
--
cul8er,
Paul
oo
pa...@gmx.net ~( "> paul_f...@s.maus.de
Dave R.
<k1ghrt833ik9e1ncm...@4ax.com>:
>Hmm, why are 3.5" disks floppy disks in the English language? They don't
>really flop do they?
The outer shell is hard, but the inner media is just as floppy as a 5 1/4"
disk's. The same also applies to Zip disks.
The media used in hard drives is noticeably stronger.
Daniel O'Shea
may be used (commodore disks are recommended)"! One of the disks I
have is labeled "SINGLE SIDE, SINGLE/DOUBLE DENSITY, 35/40 TRACK"
another is "DOUBLE SIDED, HIGH *ENERGY*, 80 TRACKS".
About 3˝" disks, I remember once reading them refered to as 'firm' -
to put them somewhere in between floppy and hard :) But I think they
are just generally called 'floppy' to distinguish them from 'hard'
disks.
Alex Eisenhut
> may be used (commodore disks are recommended)"! One of the disks I
> have is labeled "SINGLE SIDE, SINGLE/DOUBLE DENSITY, 35/40 TRACK"
> another is "DOUBLE SIDED, HIGH *ENERGY*, 80 TRACKS".
Careful with those. Wear gloves.
Glenn P.,
<eise...@technologist.com> wrote:
> > One of the disks I have is labeled "SINGLE SIDE, SINGLE/DOUBLE
> > DENSITY, 35/40 TRACK" another is "DOUBLE SIDED, HIGH *ENERGY*,
> > 80 TRACKS".
> Careful with those. Wear gloves.
LOL! And use a Geiger counter, I presume? :)
--_____ %%%%%%%%%%%%%%%% "Glenn P.," <C128...@GTI.Net> %%%%%%%%%%%%%%%%
{~._.~} ------------------------------------------------------------------
_( Y )_ "...remember, my sentimental friend, that a heart is not judged
(:_~*~_:) by how much YOU love, but by how much YOU are loved by OTHERS."
(_)-(_) --Wizard of Oz to Tin Man (MGM Movie).
Ruud Baltissen
> > Double Density disks are 96 tpi (tracks-per-inch), single density
> > disks are 48tpi. If you'd wanted to use the 'extra features' of DD,
> > you'll need a 80-tracks drive.
> Hm. I'm rather sure my Maxell (and Goldstar) floppies at home says
> "Double Sided, Double Density. 48 tpi". What does that make them,
> if SD = 48 and DD = 96?
I really looking forward seeing you talking yourself out of this one :)
Martijn van Buul
> Hm. I'm rather sure my Maxell (and Goldstar) floppies at home says
> "Double Sided, Double Density. 48 tpi". What does that make them,
> if SD = 48 and DD = 96?
Well, I may be wrong then ;)
I just checked my own stash of floppies. While all 'brand' disks
(which I didn't buy new myself ;) are 48 tpi, most no-name white label
disks claim to be 96tpi. Odd.
Anyway - it probably doesn't matter much. I've been using DD disks as
80-tracks disks for a *long* time now (Mostly on my Amiga). Way back
in time, when I bought my A500, 3.5" disks were *darn* expensive -
a 10-pack of white label 3.5" DD disks costed roughly HFL 70,-- (Eh,
that's about 32 Euro, but it's been about 13 years, I'd say), while
10 5.25" disks costed less than HFL 10,-- (About 4 Euro).
My external 5.25" diskdrive paid itself back after only 30-odd disks..
Never had any severe problems - at least, no problems which weren't
caused by me ;) Actually, 5.25" floppies have proven to be rather
sturdy - they still work after being bent, torn, twisted, spilled-coffee-over,
things like that ;)
Anders Carlsson
> Never had any severe problems - at least, no problems which
> weren't caused by me ;)
Hm. If the 1541 formats a 5.25" DD with single density, 36 tracks
and a lot of "magic" to squeeze in 170K, and a typical PC mechanism
would format it with double density, 40 tracks and plain MFM, would
that explain any of the difficulties I've encountered more than once
with a floppy that worked fine with the CBM, then formatted on PC
and again re-used with the CBM, this time with tons of read errors?
Quite early I learned to separate 5.25"'s (and 3.5"'s) used with
CBM and those used with a PC. It seemed fine to re-use a CBM disk
on a PC, but never the other way around.
--
Anders Carlsson
Martijn van Buul
>
>> Never had any severe problems - at least, no problems which
>> weren't caused by me ;)
>
> Hm. If the 1541 formats a 5.25" DD with single density, 36 tracks
> and a lot of "magic" to squeeze in 170K, and a typical PC mechanism
> would format it with double density, 40 tracks and plain MFM, would
> that explain any of the difficulties I've encountered more than once
> with a floppy that worked fine with the CBM, then formatted on PC
> and again re-used with the CBM, this time with tons of read errors?
No, unless you have the same problem with MFM CP/M disks. The only 5.25"
disks which could not be formatted on a 1541 I've seen were blasted
because I accidentally tried to format them as HD disks. Some disks
need to be formatted more than once, though, but I have that same
problem with 3.5" disks solely used by a PC.
Jim MacKenzie
"Don Judy" <hsa...@epix.net> wrote in message
news:3BB8C93E...@epix.net...
> Commodore - well it's single sided and 48 tpi,
> doesn't specifically say single density which
> would either bear out your "they didn't call
> it anything" understanding or place it in the
> rare ss-dd 48tpi category, which also is possible
> as I have one from ECHO/Mag Media.
> Commodore did say
SS/DD diskettes aren't rare... or at least they weren't once upon a time.
When I first got into computing (1982 as a user, 1984 as an owner),
single-sided disks were noticeably cheaper than double-sided disks, and were
readily available. Two or three years later, SS/DD diskettes disappeared
and I bought DS/DD disks instead.
SS/SD disks were available, though uncommonly so, in the early 1980s. I
have more than a few at home, although I don't recall ever buying an entire
box of them.
Disk prices are interesting, too. I bought my first single 5.25" SS/DD
diskette for $9.00 Canadian in 1982, a Wabash. I bought my first box of 10
Verbatim diskettes in 1984 for about $55 Canadian. I remember when a local
department store sold Qwerty diskettes for $10 a box -that was a deal! The
last 5.25" diskettes I bought were from a dealer in Calgary - in bulk
without labels (but he gave me some jackets that he had kicking around).
They cost me about $30 for 500.
Jim
peter karlsson
> HD has the very same track density as DD (96tpi, in case of a 5.25"
> disk), but has a higher bit density.
The track density is 48 TPI for DD, and 96 TPI for QD and HD. The bit
density is 5876 BPI (bits per inch) for DD and QD, and 9646 for HD. My
book¹ doesn't have any data for SD, unfortunately.
Quote:
"Disks have two types of densities: longitudinal density and linear
density. *Longitudinal density* is indicated by how many tracks can be
recorded on the disk, often expressed as a number of tracks per inch
(TPI). *Linear density* is the capability of an individual track to
store data, often indicated as a number of bits per inch (BPI).
Unfortunately, both types of densities often are interchanged
incorrectly in discussing different disks and drives."
For 3½" disks, all (DD, HD, ED) have 135 TPI, whereas the BPI are
different: 8717 for DD, 17434 for HD and 34868 for ED.
--
\\//
peter - iDOC= - http://www.softwolves.pp.se/idoc/
Statement concerning unsolicited e-mail according to Swedish law:
http://www.softwolves.pp.se/peter/reklampost.html
¹ Scott Mueller: Upgrading and repairing PCs, Eighth edition
Sam Gillett
Anders Carlsson wrote ...
>Hm. If the 1541 formats a 5.25" DD with single density, 36 tracks
>and a lot of "magic" to squeeze in 170K, and a typical PC mechanism
>would format it with double density, 40 tracks and plain MFM, would
>that explain any of the difficulties I've encountered more than once
>with a floppy that worked fine with the CBM, then formatted on PC
>and again re-used with the CBM, this time with tons of read errors?
I think this is caused by some of the old PC tracks being located between
the CBM tracks. I have no scientific proof of this, it is only theory.
However, a theory that seems logically correct.
>Quite early I learned to separate 5.25"'s (and 3.5"'s) used with
>CBM and those used with a PC. It seemed fine to re-use a CBM disk
>on a PC, but never the other way around.
In my experience, a PC disk that is formatted _twice_ on a CBM drive will
work in an acceptable manner. I like to format a PC disk three times before
using it for CBM, just to be on the safe side.
Best regards,
Sam Gillett aka Mars Probe @ Starship Intrepid 1-972-221-4088
Last 8-bit BBS in the Dallas area. Commodore lives!
Sam Gillett
Jim MacKenzie wrote ...
>Disk prices are interesting, too. I bought my first single 5.25" SS/DD
>diskette for $9.00 Canadian in 1982, a Wabash. I bought my first box of 10
>Verbatim diskettes in 1984 for about $55 Canadian. I remember when a local
>department store sold Qwerty diskettes for $10 a box -that was a deal! The
>last 5.25" diskettes I bought were from a dealer in Calgary - in bulk
>without labels (but he gave me some jackets that he had kicking around).
>They cost me about $30 for 500.
The first box of disks that I bought were DS/DD. 1984 was a long time ago,
but I think they cost $29.95 (US). I remember being careful to squeeze the
last byte out of those expensive disks when saving files to them. And also
being sure to scratch any files that were no longer needed to free up space.
It is interesting how storage media prices dropped, and continue to do so.
The first hard drive that I bought was 40 megabytes (RLL). Today, I can buy
a 40 gigabyte drive for less money! That is one sign of progress that I
don't mind at all. ;-)
Nospam9212
wrote...
>About 3˝" disks, I remember once reading them refered to as 'firm' -
>to put them somewhere in between floppy and hard :) But I think they
>are just generally called 'floppy' to distinguish them from 'hard'
>disks.
"Firm" disks ?!?! I never heard that one.. but I could get used to it...
5 1/4" and 3 1/2" disks are both called floppy because the media that holds the
data is, for lack of a better term.. floppy !! If you remove the plastic
covering, whether that covering is in itself, hard (3 1/2" disk) or "not so
hard" (5 1/4" disk), you'll find the same material used to store data on.
The term "hard-drive" is short for "hard disk drive"... meaning the media that
holds the data is rigid. This is called the "platter" or "platters".
If you think of it as the actual disk is not the whole package but rather just
the media, it'll be rather easy to see why a floppy is called "floppy"....
(or take one of each apart and see what makes it tick... I have !! Just be sure
you are ok with the idea that they may never work again !!) :)
-= Francis Yarra =-
fyarraATjunoDOTcom
http://members.aol.com/fyarra - My C64 website
http://members.aol.com/prsnl99 - My personal website
http://members.aol.com/fyarra001/drywall
bud
Hi Ville:
Group: comp.sys.cbm Date: Mon, Oct 1, 2001, 11:08pm (CDT+8) From:
vjo...@sci.fi (Ville Jouppi)
script:
>In Finnish, 8" and 5.25" disks are
>floppies and 3.5" disks are "hard bread"
>.. Can't really be bothered to find
>a good word for that in English now, sorry. :-)
How about "hard tack", or "sea biscuit"?
regards,
dowcom
--
http://community.webtv.net/dowcom/DOWCOMSAMSTRADGUIDE
Oh wow! Virtual Memory! Now to make a REALLY big RAM disk!
Ville Jouppi
>Okay, you have me on this one. 8-)
>
>I've only seen one 4040 in my life. I got to examine the internals. It
>could have been an Alps mechanism inside. Still the same 36 track hardware
>limitation though. Also, this was over 18 years ago.
Yes, I think they were alps too.. Funny head-moving mechanism - the head moves
on a big plastic disc with a spiral cut in.. The head has a small notch that
sits in the groove, and thus gets moved back and forth when the "disc" is
rotated.. :-)
>I thought that at one time the Shugart company made half-height 5.25 drives.
>Could be wrong here as well. I did have an original Shugart drive
>somewhere, it probably got lost in the all the moves I've made in my life.
Most probably. C= just happened to like doing all the decoding electronics by
themselves, hence the use of plain mechanisms until the 1581.
Don't know whether it would have been cheaper to use shugart mechanisms -
maybe they weren't as common in the end of the 70s when the big IEEE drives
came.. The 1541 has many things in common with it's ancestors, so they
couldn't design a shugart mechanism to that either.. Oh well, just speculating
here. :-)
Jeremy Sieracki
> work in an acceptable manner. I like to format a PC disk three times
before
> using it for CBM, just to be on the safe side.
I was under this impression as well, but after finding a box
of PC disks, and formatting them 3 times each, I still have
not gained any CBM formatted reliable disks, and plus my
1571 has now gone out of alignment, so beware.
Jeremy
jer...@helicon.net
Sam Gillett
Jeremy Sieracki wrote ...
>I was under this impression as well, but after finding a box
>of PC disks, and formatting them 3 times each, I still have
>not gained any CBM formatted reliable disks, and plus my
>1571 has now gone out of alignment, so beware.
Could it be something loose in the head positioning mechanism?
Axel
> I like to format a PC disk three times
> before
> > using it for CBM, just to be on the safe side.
>
> I was under this impression as well, but after finding a box
> of PC disks, and formatting them 3 times each, I still have
> not gained any CBM formatted reliable disks, and plus my
> 1571 has now gone out of alignment, so beware.
Sometimes the media is subject to mold among opther things which make the disk
unusable. I've always checked lose disk before purchasing, just to be safe.
Axel
Nospam9212 wrote:
>
>
> 5 1/4" and 3 1/2" disks are both called floppy because the media that holds the
> data is, for lack of a better term.. floppy !! If you remove the plastic
> covering, whether that covering is in itself, hard (3 1/2" disk) or "not so
> hard" (5 1/4" disk), you'll find the same material used to store data on.
>
> The term "hard-drive" is short for "hard disk drive"... meaning the media that
> holds the data is rigid. This is called the "platter" or "platters".
>
Generally, the platter is glass or metal, while the floppy is thin plastic. Hard
disks are neat once opened, it really gives you an idea of how accurate the
positioning of the head muyst be in order to read data, when you look at the fact
that disks usually have 300 cylinders minimum, tracks over each other, to record
data.
Alex Eisenhut
> I was under this impression as well, but after finding a box
> of PC disks, and formatting them 3 times each, I still have
> not gained any CBM formatted reliable disks, and plus my
> 1571 has now gone out of alignment, so beware.
>
Bulk 'em?
bud
Hi Jeremy:
Group: comp.sys.cbm Date: Wed, Oct 3, 2001, 2:50pm (CDT+1) From:
jer...@helicon.net (Jeremy Sieracki)
script:
>I was under this impression as well,
>but after finding a box of PC disks,
>and formatting them 3 times each,
>I still have not gained any CBM
>formatted reliable disks, and plus
>my 1571 has now gone out of
>alignment, so beware.
>Jeremy
>jer...@helicon.net
OK,... here's an idea for any of you with Central Point's CopyIIPC prog
& a PC with 5 1/4" drive:
I have used the prog to try and dupe a C64 diskette. I don't have a CBM
drive to test the results, but CopyIIPC didn't say it had a problem with
the results. (And it's usually pretty fussy about its own work.)
Boot up the prog on the PC, and give it a CBM disk to dupe on the IBM
format disks. Even if it doesn't do a perfect job, enough of the CBM
format should be "burned in" by the strong PC drive to help you out.
Another possibility is the Bulkerase prog on the CopyIIPC disk. This is
alleged to "clean" even the format off of a diskette. Haven't tried it.
Glenn P.,
> In my experience, a PC disk that is formatted _twice_ on a CBM drive will
> work in an acceptable manner. I like to format a PC disk three times before
> using it for CBM, just to be on the safe side.
Jeez! Wouldn't using a disk demagnetizer prior to formatting be easier (to
say NOTHING of taking less time)...???
--_____ %%%%%%%%%%%%%%% "Glenn P.," <C128...@GTI.Net> %%%%%%%%%%%%%%%
{~._.~} -----------------------------------------------------------------
_( Y )_ "You know", he added very gravely, "it's one of the most
(:_~*~_:) serious things that can possibly happen to one in a battle --
(_)-(_) to get one's head cut off."
========= ---------------
///////// --Tweedledee, in Chapter IV, "Tweedledum And Tweedledee",
========= of "Through The Looking-Glass" by Lewis Carroll.
Sam Gillett
Glenn P., wrote ...
>Jeez! Wouldn't using a disk demagnetizer prior to formatting be easier (to
>say NOTHING of taking less time)...???
Yes, but my bulk eraser disappeared several years ago. Time is no problem
as my PC is right next to my C128. I can do something on it, like reply to
e-mail, or read a newsgroup, while formatting a disk on the Commodore.
Besides, the fact that the original poster was having difficulty formatting
PC disks for CBM indicated that he has no bulk eraser, and needed an
alternate method, as I did when mine disappeared.
Axel
"Glenn P.," wrote:
> On Tue., 02-Oct-2001, at 08:07pm, "Sam Gillett" <samgi...@msn.com> wrote:
>
> > In my experience, a PC disk that is formatted _twice_ on a CBM drive will
> > work in an acceptable manner. I like to format a PC disk three times before
> > using it for CBM, just to be on the safe side.
>
> Jeez! Wouldn't using a disk demagnetizer prior to formatting be easier (to
> say NOTHING of taking less time)...???
>
Or just use one of those old colour TVs circa 1980, they just do wonders in
demagnitising any magnetic media within 3 ft. I used to have to pull out my
commodore vic 20 4 ft from the TV and pull out the datasette out further to avoid
loading problems. VCR tapes could be completely demagnitised in 2 days by just
leaving them underneath.
Glenn P.,
>> Jeez! Wouldn't using a disk demagnetizer prior to formatting be easier
>> (to say NOTHING of taking less time)...???
> Yes, but my bulk eraser disappeared several years ago.
Two words: RADIO SHACK
Duh!
-- %%%%%%%%%%%%%%% "Glenn P.," <C128...@GTI.Net> %%%%%%%%%%%%%%%
_____ -----------------------------------------------------------------
{~._.~} "...Nor is it strange,
_( Y )_ After changes upon changes, we are more or less the same;
(:_~*~_:) After changes, we are more or less the same..."
(_)-(_) --------------------------------
========= --SIMON, Paul; & GARFUNKLE, Art:
========= "The Boxer" (Sung In Concert).
Axel
"Glenn P.," wrote:
> Two words: RADIO SHACK
>
And when you go there and ask for a bulk eraser, the response is:
>
> Duh!
>
mike
<samgi...@msn.com> writes:
>
>I think this is caused by some of the old PC tracks being located between
>the CBM tracks. I have no scientific proof of this, it is only theory.
>However, a theory that seems logically correct.
>
That is what my thoughts are - that the CBM drive is not completely rewriting
the disk.
I would suggest using a bulk eraser to completely erase the disk before
formatting it in the CBM drive.
Mike
Glenn P.,
>> "Glenn P.," wrote:
>> Two words: RADIO SHACK
>> Duh!
I actually HAVE one, it's a Realistic[tm], catalog #44-232. They should
still be being manufactured; it's not the sort of thing that becomes
obsolete.
But even if it ISN'T still being made, Radio Shack should still be able
to tell you were to get one.
So get off your LAZY DUFF, and MOVE!
To repeat myself: DUH!!!
--_____ "...We'll die if we have to, but not one second *earlier*
{~._.~} than we have to. Everyone has to die someday; there's no
_( Y )_ escaping that, but *quitting* isn't compulsory."
(:_~*~_:) -- "Lucky Starr And The Oceans Of Venus",
(_)-(_) "Glenn P.," ...By: Isaac Asimov (1954).
--------- <C128...@GTI.Net>
Matthew Montchalin
| >> Two words: RADIO SHACK
|
| > And when you go there and ask for a bulk eraser, the response is:
|
| >> Duh!
|
|I actually HAVE one, it's a Realistic[tm], catalog #44-232. They should
|still be being manufactured; it's not the sort of thing that becomes
|obsolete.
|
|But even if it ISN'T still being made, Radio Shack should still be able
|to tell you were to get one.
|
|So get off your LAZY DUFF, and MOVE!
Say, does Radio Shack make bulk erasers for stripe cards? Some people
call stripe cards "security cards" if they are used for securing
facilities like laboratories or military installations. You know,
those cards that look like VISA/Mastercard/American Express Cards.
You can store all kinds of stuff on those cards if you have a reader/
writer.
Anyway, using a jittering 'magnet' on a stripe card with your hands
is not a very reliable way of 'erasing' the data on those things.