Hmm.. was there ever an 8" floppy drive for the BBC?

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Pernod
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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by Pernod » Tue Sep 10, 2019 6:21 pm

gtoal wrote:
Tue Sep 10, 2019 5:34 pm
Could some kind soul please extract the contents of D1000.IMG and D1000B.IMG from http://gtoal.com/bbc/ ?
Just rename them to .ssd and mount in BeebEm, then use Edit->Export Files from Disc.

The DNFS30 ROM image is the standard DNFS.
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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by gtoal » Tue Sep 10, 2019 6:52 pm

I guess I could do that, but I have several hundred images to unpack and was waiting until I could find a command line program that I could script to do them all at once rather than each one manually through a GUI :-/

The 8in DFS code in that drive image takes the standard rom and patches it and writes out a new image. If I remember right, it disables the net part of the rom. I can't remember if it changes the filing system number or not to allow regular DFS to work at the same time - it's been a long time...

G
Last edited by gtoal on Tue Sep 10, 2019 6:52 pm, edited 1 time in total.

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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by davidb » Tue Sep 10, 2019 9:43 pm

I extracted the files from D1000.IMG but couldn't manage to do the same from D1000B.IMG. What kind of format is that using?
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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by BeebMaster » Tue Sep 10, 2019 10:40 pm

D1000B.IMG is a corrupt DFS disc image containing one file. The catalogue and map at the first two sectors have been overwritten with zeroes, then a BASIC file starts at sector 2 which is attached.
D1000B,ffb.zip
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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by Coeus » Wed Sep 11, 2019 12:25 am

gtoal wrote:
Tue Sep 10, 2019 6:52 pm
I guess I could do that, but I have several hundred images to unpack and was waiting until I could find a command line program that I could script to do them all at once rather than each one manually through a GUI :-/
Check out SWH's beeb perl script: https://www.spuddy.org/Beeb/mmb_utils.html
Last edited by Coeus on Wed Sep 11, 2019 12:31 am, edited 1 time in total.

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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by gtoal » Wed Sep 11, 2019 2:39 am

davidb wrote:
Tue Sep 10, 2019 9:43 pm
I extracted the files from D1000.IMG but couldn't manage to do the same from D1000B.IMG. What kind of format is that using?
Thanks DavidB and BeebMaster! So looks like everything is there that the folks who wanted to build an 8in drive need :-)

Here are the basic sources needed to build a DFS rom (with tube support of course) and a formatter.

http://gtoal.com/bbc/D1000/B.NEWPROC.txt
http://gtoal.com/bbc/D1000/B.NMIPROC.txt
http://gtoal.com/bbc/D1000/BUILD.txt
http://gtoal.com/bbc/D1000/Form77s.txt
http://gtoal.com/bbc/D1000/GRABBER.txt
http://gtoal.com/bbc/D1000/SENDER.txt


We only implemented the 8in support for fun back then, I don't think we ever had a practical use for it. As far as I remember the only 8in floppy we ever wrote contained the same files as that 5.25 image with the DFS and formatter :-)

G
Last edited by gtoal on Thu Sep 12, 2019 8:47 pm, edited 2 times in total.

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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by gtoal » Wed Sep 11, 2019 4:56 am

Coeus wrote:
Wed Sep 11, 2019 12:25 am
gtoal wrote:
Tue Sep 10, 2019 6:52 pm
I guess I could do that, but I have several hundred images to unpack and was waiting until I could find a command line program that I could script to do them all at once rather than each one manually through a GUI :-/
Check out SWH's beeb perl script: https://www.spuddy.org/Beeb/mmb_utils.html
That did the trick. A few images were corrupt but I found a lot that was useful. Will sort it out and post later.

G

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Re: Hmm.. was there ever an 8" floppy drive for the BBC?

Post by BeebMaster » Wed Sep 11, 2019 4:35 pm

It's interesting to learn about the history of the BBC micro disc interface. Until now I'd never really given any thought to the capacity difference between 8" and 5.25" discs, I think I'd always thought that an 8" BBC micro floppy disc, if one had ever existed, would just be 80T 200K in DFS like a 5.25" disc.

I think the fact that there was never a 77-track 8" DFS ROM or formatter officially released tells us that there weren't any 8" floppy drives envisaged for general use.

However if we compare and contrast the 1982 and 1985 editions of the service manual: the disc upgrade instructions in the 1982 version don't mention 5.25/8" at all, the only references to disc size are elsewhere, eg. in the link survey. By 1985 for some reason there are separate upgrade instruction sections for 5.25" interface and 8" interface - although the 8 inch one purely says do the 5.25" upgrade and then alter 3 links.
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