Help reading a BBC 80trk ADFS disk

[pgb1975]

Hi,

I've got a Greaseweazle 4.1 and a TEAC FD-55GFR, and I'm trying to read an 80 track 5.25" disc from a BBC B running Watford ADFS c.1990

I've used

gw read --format=acorn.adfs.640 disk_img.img

and after chugging away for a while with output like this

Reading c=0-79:h=0-1 revs=2 Format acorn.adfs.640 T0.0: IBM MFM (0/16 sectors) from Raw Flux (70937 flux in 400.60ms) T0.0: IBM MFM (0/16 sectors) from Raw Flux (106327 flux in 600.60ms) (Retry #1.1) T0.0: IBM MFM (0/16 sectors) from Raw Flux (106329 flux in 600.60ms) (Retry #1.2) T0.0: IBM MFM (0/16 sectors) from Raw Flux (106327 flux in 600.60ms) (Retry #1.3) T0.0: Giving up: 16 sectors missing T0.1: IBM MFM (0/16 sectors) from Raw Flux (71491 flux in 400.60ms) T0.1: IBM MFM (0/16 sectors) from Raw Flux (107159 flux in 600.60ms) (Retry #1.1) T0.1: IBM MFM (0/16 sectors) from Raw Flux (107161 flux in 600.60ms) (Retry #1.2) T0.1: IBM MFM (0/16 sectors) from Raw Flux (107161 flux in 600.60ms) (Retry #1.3) T0.1: Giving up: 16 sectors missing

it says Found 0 sectors of 2560 (0%)

I'm really just asking for confirmation I've used the right commandline, and that the 1200KB 360rpm drive doesn't need extra options to help it read the old format.

Many thanks,
Peter.

[Hanzugam]

Is there info what brand, model and type of floppy drive there was in that particular BBC MAster Model B where the floppy disk was originally written?

https://en.wikipedia.org/wiki/BBC_Micro#Specifications tells it had either Intel 8271 controller and later on WD1770 https://en.wikipedia.org/wiki/WD1770:
"The 8271 controller was of limited functionality and obsolete, and later versions of the file system from various vendors including Solidisk, Acorn and Watford Electronics were based on the later WD1770 and WD1772 drive controllers. The 1770 controller quickly became the standard controller in the Acorn range following the advent of ADFS.

https://en.wikipedia.org/wiki/Disc_Filing_System#Alternatives continues:
"The DFS was superseded by the Advanced Disc Filing System (ADFS) which was fully hierarchical and was suitable for running hard drives on the BBC Micro. The ADFS was the default filing system on the BBC Master but most users are likely to have reverted to the DFS for compatibility reasons; ADFS could not read DFS discs. The ADFS was also chosen as the standard filing system for RISC OS."

Your TEAC FD-55GFR https://www.vogonswiki.com/index.php/Teac_FD-55GFR (if it is working), should be very cabable drive including many jumpers to experiment with and 52 page documentation should help on that : https://deramp.com/downloads/floppy_drives/teac/TEAC%20FD-55GFR.pdf

In case that BBC Master Model B wrote the floppy in 250 kbps at 300 RPM. It would not hurt to try:

gw read --rate=250 --format=acorn.adfs.640 disk_img.img

or even

gw read --rate=300 --format=acorn.adfs.640 disk_img.img

If that does not help, try hard to see if you find an empty jumper like DD, HS, JC or R/M in TEAC that switches to 300 RPM for DD media.

[drdpj]

Just saw this - watford will be DFS, not ADFS. That's your issue. Use one of the Acorn DFS formats. As a rule, with an unknown or unclear format, image directly to SCP or kryoflux stream then have a look at what's actually there with something like the HxCFloppyEmulator software. Once you know what you're looking at you can then specify a format. It's actually (in my opinion) best practice to dump directly to a stream format and then perform any conversion to a sector image afterwards. That way you know you've at least captured most of the data if the disk decides to fall apart...

…

On Mon, 5 Jan 2026 at 09:05, Hanzu ***@***.***> wrote: Is there info what brand, model and type of floppy drive there was in that particular BBC MAster Model B where the floppy disk was originally written? https://en.wikipedia.org/wiki/BBC_Micro#Specifications tells it had either Intel 8271 controller and later on WD1770 https://en.wikipedia.org/wiki/WD1770: "The 8271 controller was of limited functionality and obsolete, and later versions of the file system from various vendors including Solidisk, Acorn and *Watford* Electronics were based on the later WD1770 and WD1772 drive controllers. The 1770 controller quickly became the standard controller in the Acorn range following the advent of ADFS. https://en.wikipedia.org/wiki/Disc_Filing_System#Alternatives continues: "The DFS was superseded by the Advanced Disc Filing System (ADFS) which was fully hierarchical and was suitable for running hard drives on the BBC Micro. The ADFS was the default filing system on the BBC Master but most users are likely to have reverted to the DFS for compatibility reasons; *ADFS could not read DFS discs.* The ADFS was also chosen as the standard filing system for RISC OS." Your TEAC FD-55GFR https://www.vogonswiki.com/index.php/Teac_FD-55GFR (if it is working), should be very cabable drive including many jumpers to experiment with and 52 page documentation should help on that : https://deramp.com/downloads/floppy_drives/teac/TEAC%20FD-55GFR.pdf In case that BBC Master Model B wrote the floppy in 250 kbps at 300 RPM. It would not hurt to try: gw read --rate=250 --format=acorn.adfs.640 disk_img.img or even gw read --rate=300 --format=acorn.adfs.640 disk_img.img If that does not help. See if you find a jumper in TEAC that switches to 300 RPM for DD media. — Reply to this email directly, view it on GitHub <#601 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AATU2PB4RRHPZ5DJMPEAKED4FISNXAVCNFSM6AAAAACNWCFKNGVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTKNBRGI3DAOA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[pgb1975]

Thank you very much, both of you. I successfully read the disk as a single-sided DFS disk.