[BBC-Micro] Fw: DD & HD Floppies

Bob Devries devries.bob at gmail.com
Sun Oct 17 10:57:55 BST 2010


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" <bbc at pdcurran.co.uk>
To: <bbc-micro at lists.cloud9.co.uk>
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 <devries.bob at gmail.com> 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" <bbc at pdcurran.co.uk>
>> To: <bbc-micro at lists.cloud9.co.uk>
>> 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 <rick at rs432.net> 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"?
>> >> <giggle>
>> >>
>> >>
>> >> > 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...
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> bbc-micro mailing list
>> >> bbc-micro at lists.cloud9.co.uk
>> >> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
>> >>
>> >
>>
>>
>>
>> --------------------------------------------------------------------------------
>>
>>
>> > _______________________________________________
>> > bbc-micro mailing list
>> > bbc-micro at lists.cloud9.co.uk
>> > http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
>> >
>>
>>
>> _______________________________________________
>> bbc-micro mailing list
>> bbc-micro at lists.cloud9.co.uk
>> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
>>
>


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


> _______________________________________________
> bbc-micro mailing list
> bbc-micro at lists.cloud9.co.uk
> http://lists.cloud9.co.uk/mailman/listinfo/bbc-micro
> 




More information about the bbc-micro mailing list