Ok cheers.
Better stick to DD then.
Anyone know why it happens?

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My understanding is that HD floppies need a higher write current
for the 'denser' medium. If you fool a drive into thinking it's
a DD disk then the medium only gets 'partially' written.
The other way around is as bad too, where a high write current
on an easy to magnetise medium leads to the medium being
'over magnetised' and therefore cannot be properly erased.

If the technicalities aren't quite right, I hope the general
principle isn't far off.




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On 16/10/2010 16:33, Jason Flynn G7OCD wrote:

> If the technicalities aren't quite right, I hope the general
> principle isn't far off.

There may, however, come a day when there isn't much choice...


I looked on Amazon.co.uk for "floppy disc 5.25" and I got no floppies,
but I did have "Apec Pair Rear Brake Discs - Ford Mondeo - 2.5 -
10/2000-3/2007 - 280mm Solid". Remembering somebody who couldn't list
little glass animals on Amazon, I'm wondering WTF Mondeo brake discs are
doing there!
There are only HD 3.5" floppies on Amazon.


www.grosbill.com [French] don't even list floppies. At all.

www.pearl.fr lists three 3.5" floppy drives [internal, USB,
internal-with-card-reader]. And no blank media. Hmmm...


The best I could find for 5.25 was:
http://www.amazon.com/Floppy-Disks-5-25-Inch-Md2hd/dp/B002DGWE8A/
Any guesses on postage costs?


Best wishes,

Rick.

--
Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...

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?I haven't ordered from them yet, but these folk appear to have stock of
both 3.5/DD and 5.25/DD:

http://www.floppydisks.com

There doesn't seem to be anything that indicates that they won't ship to
that side of the pond (this side gets free shipping, though!).

..Kieran


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On 17/10/2010 06:19, Kieran Mockford wrote:

> http://www.floppydisks.com

Nice to see somebody still keeping the floppy alive. But, what, no 8"?



> There doesn't seem to be anything that indicates that they won't ship to
> that side of the pond (this side gets free shipping, though!).

I went to perform a pretend-purchase of 20 5.25s to see what sort of
shipping would be involved. The site tries to pass you over to Google
Checkout, at which point NoScript put its foot down:
--8<--------
[NoScript XSS] Sanitised suspicious upload to
[https://checkout.google.com/api/checkout/v2/checkoutForm/Merchant/655251604398233]
from [http://www.floppydisks.com/view_cart.php]: transformed into a
download-only GET request.
--8<--------

Funny. The place I get Japanese food from works fine with its bank, my
geek-bits site works fine with its banking service. Hell, even EDF works
when it passes you all over the place. But this one triggers NoScript.
Probably okay, but I'm paranoid when it comes to my credit card info and
the Internet... and if they can't get this itty-bitty detail right.....


Best wishes,

Rick.

--
Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...



_______________________________________________
___________________________________________________

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Silly question, but I'm just taking a step back from this and thinking that
instead of adapting HD disks to work in DD drives, what are the chances of
getting standard 1.44M HD drives to work on the BBC?

There are probably good reasons why this hasn't happened, just wondering if
any of them weren't insurmountable. I know there are likely to be issues
with the smaller heads used in HD drives when writing DD disks to be read on
DD drives, the same sort of issues that causes all the fun with 40 track
disks written by 80 track drives. Are there also issues with catalogue sizes
or track counts?

The ideal would be adapting one of the DFS's to work with 1.44M disks -
unless any of them do already? Otherwise some hardware mod to use HD drives
and disks as if they were DD drives and disks. Double all the track steps
and perhaps even repeat every write on the next track to increase the
chances of DD compatibility?

Just a thought?

Dave

On 17 October 2010 05:33, Rick Murray <> wrote:

> On 17/10/2010 06:19, Kieran Mockford wrote:
>
> > http://www.floppydisks.com
>
> Nice to see somebody still keeping the floppy alive. But, what, no 8"?
>
>
>
> > There doesn't seem to be anything that indicates that they won't ship to
> > that side of the pond (this side gets free shipping, though!).
>
> I went to perform a pretend-purchase of 20 5.25s to see what sort of
> shipping would be involved. The site tries to pass you over to Google
> Checkout, at which point NoScript put its foot down:
> --8<--------
> [NoScript XSS] Sanitised suspicious upload to
> [
> https://checkout.google.com/api/checkout/v2/checkoutForm/Merchant/655251604398233
> ]
> from [http://www.floppydisks.com/view_cart.php]: transformed into a
> download-only GET request.
> --8<--------
>
> Funny. The place I get Japanese food from works fine with its bank, my
> geek-bits site works fine with its banking service. Hell, even EDF works
> when it passes you all over the place. But this one triggers NoScript.
> Probably okay, but I'm paranoid when it comes to my credit card info and
> the Internet... and if they can't get this itty-bitty detail right.....
>
>
> Best wishes,
>
> Rick.
>
> --
> Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
> BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
> E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...
>
>
>
> _______________________________________________
___________________________________________________

Posted on the Bbc-micro mailing list. Go to http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro to subscribe.

Dave,

I think that neither of the floppy disc chips used in the BBC are capable of
the double data rate.

Regards, Bob Devries

----- Original Message -----
From: "Dave Curran" <>
To:
Sent: Sunday, October 17, 2010 6:36 PM
Subject: Re: [BBC-Micro] Fw: DD & HD Floppies


> Silly question, but I'm just taking a step back from this and thinking
> that
> instead of adapting HD disks to work in DD drives, what are the chances of
> getting standard 1.44M HD drives to work on the BBC?
>
> There are probably good reasons why this hasn't happened, just wondering
> if
> any of them weren't insurmountable. I know there are likely to be issues
> with the smaller heads used in HD drives when writing DD disks to be read
> on
> DD drives, the same sort of issues that causes all the fun with 40 track
> disks written by 80 track drives. Are there also issues with catalogue
> sizes
> or track counts?
>
> The ideal would be adapting one of the DFS's to work with 1.44M disks -
> unless any of them do already? Otherwise some hardware mod to use HD
> drives
> and disks as if they were DD drives and disks. Double all the track steps
> and perhaps even repeat every write on the next track to increase the
> chances of DD compatibility?
>
> Just a thought?
>
> Dave
>
> On 17 October 2010 05:33, Rick Murray <> wrote:
>
>> On 17/10/2010 06:19, Kieran Mockford wrote:
>>
>> > http://www.floppydisks.com
>>
>> Nice to see somebody still keeping the floppy alive. But, what, no 8"?
>>
>>
>>
>> > There doesn't seem to be anything that indicates that they won't ship
>> > to
>> > that side of the pond (this side gets free shipping, though!).
>>
>> I went to perform a pretend-purchase of 20 5.25s to see what sort of
>> shipping would be involved. The site tries to pass you over to Google
>> Checkout, at which point NoScript put its foot down:
>> --8<--------
>> [NoScript XSS] Sanitised suspicious upload to
>> [
>> https://checkout.google.com/api/checkout/v2/checkoutForm/Merchant/655251604398233
>> ]
>> from [http://www.floppydisks.com/view_cart.php]: transformed into a
>> download-only GET request.
>> --8<--------
>>
>> Funny. The place I get Japanese food from works fine with its bank, my
>> geek-bits site works fine with its banking service. Hell, even EDF works
>> when it passes you all over the place. But this one triggers NoScript.
>> Probably okay, but I'm paranoid when it comes to my credit card info and
>> the Internet... and if they can't get this itty-bitty detail right.....
>>
>>
>> Best wishes,
>>
>> Rick.
>>
>> --
>> Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
>> BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
>> E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...
>>
>>
>>
>> _______________________________________________
___________________________________________________

Posted on the Bbc-micro mailing list. Go to http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro to subscribe.

Fair point, that though hit me after I had posted.

But it's not like it hasn't happened before. Just as the 8271 was replaced
by the plug in 1770 replacement, why not a plug in module with a controller
capable of using the standard 1.44M drives. These days it should be possible
to get a small microcontroller to do an impersonation of the relevant
controller, with added capabilities. Just a pic on a module to droped into
the 8271 socket on a bbc, more of an issue for the master though. The 1770
is quite will documented, and the floppy interface seems reasonably straight
forward. It doesn't sound unreasonable?

Dave

On 17 October 2010 10:25, Bob Devries <> wrote:

> Dave,
>
> I think that neither of the floppy disc chips used in the BBC are capable
> of
> the double data rate.
>
> Regards, Bob Devries
>
> ----- Original Message -----
> From: "Dave Curran" <>
> To:
> Sent: Sunday, October 17, 2010 6:36 PM
> Subject: Re: [BBC-Micro] Fw: DD & HD Floppies
>
>
> > Silly question, but I'm just taking a step back from this and thinking
> > that
> > instead of adapting HD disks to work in DD drives, what are the chances
> of
> > getting standard 1.44M HD drives to work on the BBC?
> >
> > There are probably good reasons why this hasn't happened, just wondering
> > if
> > any of them weren't insurmountable. I know there are likely to be issues
> > with the smaller heads used in HD drives when writing DD disks to be read
> > on
> > DD drives, the same sort of issues that causes all the fun with 40 track
> > disks written by 80 track drives. Are there also issues with catalogue
> > sizes
> > or track counts?
> >
> > The ideal would be adapting one of the DFS's to work with 1.44M disks -
> > unless any of them do already? Otherwise some hardware mod to use HD
> > drives
> > and disks as if they were DD drives and disks. Double all the track steps
> > and perhaps even repeat every write on the next track to increase the
> > chances of DD compatibility?
> >
> > Just a thought?
> >
> > Dave
> >
> > On 17 October 2010 05:33, Rick Murray <> wrote:
> >
> >> On 17/10/2010 06:19, Kieran Mockford wrote:
> >>
> >> > http://www.floppydisks.com
> >>
> >> Nice to see somebody still keeping the floppy alive. But, what, no 8"?
> >>
> >>
> >>
> >> > There doesn't seem to be anything that indicates that they won't ship
> >> > to
> >> > that side of the pond (this side gets free shipping, though!).
> >>
> >> I went to perform a pretend-purchase of 20 5.25s to see what sort of
> >> shipping would be involved. The site tries to pass you over to Google
> >> Checkout, at which point NoScript put its foot down:
> >> --8<--------
> >> [NoScript XSS] Sanitised suspicious upload to
> >> [
> >>
> https://checkout.google.com/api/checkout/v2/checkoutForm/Merchant/655251604398233
> >> ]
> >> from [http://www.floppydisks.com/view_cart.php]: transformed into a
> >> download-only GET request.
> >> --8<--------
> >>
> >> Funny. The place I get Japanese food from works fine with its bank, my
> >> geek-bits site works fine with its banking service. Hell, even EDF works
> >> when it passes you all over the place. But this one triggers NoScript.
> >> Probably okay, but I'm paranoid when it comes to my credit card info and
> >> the Internet... and if they can't get this itty-bitty detail right.....
> >>
> >>
> >> Best wishes,
> >>
> >> Rick.
> >>
> >> --
> >> Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
> >> BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
> >> E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...
> >>
> >>
> >>
> >> _______________________________________________
___________________________________________________

Posted on the Bbc-micro mailing list. Go to http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro to subscribe.

Hi Dave,

I'm not sure that the Beeb can run fast enough to service a chip like the
37C65 or equivalent. It would at least require a lot of very tight code.

Regards, Bob Devries

----- Original Message -----
From: "Dave Curran" <>
To:
Sent: Sunday, October 17, 2010 7:42 PM
Subject: Re: [BBC-Micro] Fw: DD & HD Floppies


> Fair point, that though hit me after I had posted.
>
> But it's not like it hasn't happened before. Just as the 8271 was replaced
> by the plug in 1770 replacement, why not a plug in module with a
> controller
> capable of using the standard 1.44M drives. These days it should be
> possible
> to get a small microcontroller to do an impersonation of the relevant
> controller, with added capabilities. Just a pic on a module to droped into
> the 8271 socket on a bbc, more of an issue for the master though. The 1770
> is quite will documented, and the floppy interface seems reasonably
> straight
> forward. It doesn't sound unreasonable?
>
> Dave
>
> On 17 October 2010 10:25, Bob Devries <> wrote:
>
>> Dave,
>>
>> I think that neither of the floppy disc chips used in the BBC are capable
>> of
>> the double data rate.
>>
>> Regards, Bob Devries
>>
>> ----- Original Message -----
>> From: "Dave Curran" <>
>> To:
>> Sent: Sunday, October 17, 2010 6:36 PM
>> Subject: Re: [BBC-Micro] Fw: DD & HD Floppies
>>
>>
>> > Silly question, but I'm just taking a step back from this and thinking
>> > that
>> > instead of adapting HD disks to work in DD drives, what are the chances
>> of
>> > getting standard 1.44M HD drives to work on the BBC?
>> >
>> > There are probably good reasons why this hasn't happened, just
>> > wondering
>> > if
>> > any of them weren't insurmountable. I know there are likely to be
>> > issues
>> > with the smaller heads used in HD drives when writing DD disks to be
>> > read
>> > on
>> > DD drives, the same sort of issues that causes all the fun with 40
>> > track
>> > disks written by 80 track drives. Are there also issues with catalogue
>> > sizes
>> > or track counts?
>> >
>> > The ideal would be adapting one of the DFS's to work with 1.44M disks -
>> > unless any of them do already? Otherwise some hardware mod to use HD
>> > drives
>> > and disks as if they were DD drives and disks. Double all the track
>> > steps
>> > and perhaps even repeat every write on the next track to increase the
>> > chances of DD compatibility?
>> >
>> > Just a thought?
>> >
>> > Dave
>> >
>> > On 17 October 2010 05:33, Rick Murray <> wrote:
>> >
>> >> On 17/10/2010 06:19, Kieran Mockford wrote:
>> >>
>> >> > http://www.floppydisks.com
>> >>
>> >> Nice to see somebody still keeping the floppy alive. But, what, no 8"?
>> >>
>> >>
>> >>
>> >> > There doesn't seem to be anything that indicates that they won't
>> >> > ship
>> >> > to
>> >> > that side of the pond (this side gets free shipping, though!).
>> >>
>> >> I went to perform a pretend-purchase of 20 5.25s to see what sort of
>> >> shipping would be involved. The site tries to pass you over to Google
>> >> Checkout, at which point NoScript put its foot down:
>> >> --8<--------
>> >> [NoScript XSS] Sanitised suspicious upload to
>> >> [
>> >>
>> https://checkout.google.com/api/checkout/v2/checkoutForm/Merchant/655251604398233
>> >> ]
>> >> from [http://www.floppydisks.com/view_cart.php]: transformed into a
>> >> download-only GET request.
>> >> --8<--------
>> >>
>> >> Funny. The place I get Japanese food from works fine with its bank, my
>> >> geek-bits site works fine with its banking service. Hell, even EDF
>> >> works
>> >> when it passes you all over the place. But this one triggers NoScript.
>> >> Probably okay, but I'm paranoid when it comes to my credit card info
>> >> and
>> >> the Internet... and if they can't get this itty-bitty detail
>> >> right.....
>> >>
>> >>
>> >> Best wishes,
>> >>
>> >> Rick.
>> >>
>> >> --
>> >> Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
>> >> BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
>> >> E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...
>> >>
>> >>
>> >>
>> >> _______________________________________________
___________________________________________________

Posted on the Bbc-micro mailing list. Go to http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro to subscribe.

>> > Silly question, but I'm just taking a step back from this and thinking
>> > that
>> > instead of adapting HD disks to work in DD drives, what are the chances
>> > of
>> > getting standard 1.44M HD drives to work on the BBC?

It HAS been done - there was thread on the STH forums some time back.
ISTR it involved a fairly minor hack to a n otherwise standard
1770/1772 board, but some /very/ tight code in the re-written disc
routines to cope with the much faster speed that the data arrived from
the drive.

Rob

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