A 200Kb into a 199.5Kb pot!

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Bat
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A 200Kb into a 199.5Kb pot!

Post by Bat » Thu Apr 26, 2018 8:23 pm

Hi,
I've downloaded some DSD images which I want to use on my BBC B.
I've got a Turbo MMC and the MMB Imager s/w that came with it.
That s/w will split the 400Kb into, wait for it, 2 x 200KB SSDs.
Prefect :)
Now drag and drop them into Imager, no it won't play! :x
The only reason I can see is the Imager reports the "slots" available as 199.5 and I'm trying to drop 200 in there.
Has anyone else come across this?
The DSDs are Torch Z80 system discs if that has any bearing on the stituation?
I don't mind transferring them onto Floppies but I need to get them on the beeb first.
Hope you can help :)
Cheers,
Gavin :)

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danielj
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Re: A 200Kb into a 199.5Kb pot!

Post by danielj » Thu Apr 26, 2018 8:35 pm

I've not tried this, so I don't know how far you'll get on this... Torch images I think are properly interleaved across both sides of the floppy, so they'll never work natively with turbommc (and besides, CP/N expects to find an 8271 to use, so it'll always go for the actual floppy drives). You'll have to do a precise sector-by-sector back to floppy discs for each side and standard copy utilities won't do this, especially not with turbommc iirc...

UPURS might be a better solution? Failing that, a Gotek with flashfloppy will work perfectly too :)

d.

(I wrote some utilities for putting files onto torch images, and left a description of the format in the file!): https://github.com/drdpj/TorchCPN/blob/ ... Image.java

Bat
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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Thu Apr 26, 2018 8:50 pm

Hi,
Thanks Daniel :)
Where can I purchase all this stuff I wasn't planning on please? :roll: :lol:
Cheers,
Gavin :)

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danielj
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Re: A 200Kb into a 199.5Kb pot!

Post by danielj » Thu Apr 26, 2018 9:01 pm

UPURS is a build it yourself:

https://www.retro-kit.co.uk/UPURS/

Gotek, buy one from china on ebay (£12, eg: https://www.ebay.co.uk/itm/152559229902), and use a USB-A to USB-A cable (e.g. https://www.ebay.co.uk/itm/261401218983) to reflash the firmware with flashfloppy: https://github.com/keirf/FlashFloppy/wiki

There are further mods you can then make to it to improve things, as outlined in the wiki, but it'll work just like that in the first instance :)

d.

Bat
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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Thu Apr 26, 2018 9:11 pm

Thanks :)
More resarch to do :)

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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Thu Apr 26, 2018 9:13 pm

Which do you think would be the easiest to implement?
I don't mind making a cable, I'm looking for something straight forward to operate :)

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danielj
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Re: A 200Kb into a 199.5Kb pot!

Post by danielj » Thu Apr 26, 2018 9:20 pm

Depends what you want - the gotek replaces the floppy drive with something solid state - you can use it with anything from normal dfs images to adfs images to other computers. UPURS lets you copy disc images to and from real floppies at high speed? These days I just use goteks as it's much easier than faffing with floppies :) - you will need to burn a rom to use UPURS, but the gotek will work fine so long as you've got a normal floppy interface/dfs installed.

d.

Bat
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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Thu Apr 26, 2018 9:27 pm

What cable do you need for the gotek to disk drive port please?

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danielj
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Re: A 200Kb into a 199.5Kb pot!

Post by danielj » Fri Apr 27, 2018 5:09 am

Just a 34way floppy cable with no twist in it.

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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Fri Apr 27, 2018 8:12 am

Hi,
Thanks for all the info, saved me ages looking it all up!
I'm going with Gotek as the "use it for everything" will come in handy with a 72 track digital mixing desk, PCs, etc!
Cheers,
Gavin :)

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jgharston
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Re: A 200Kb into a 199.5Kb pot!

Post by jgharston » Fri Apr 27, 2018 9:55 am

Bat wrote:I've got a Turbo MMC and the MMB Imager s/w that came with it.
...
The DSDs are Torch Z80 system discs if that has any bearing on the stituation?
It could be the MMB Imager is examining the contents of the disk images expecting to find a DFS filesystem and interpreting the contents as a DFS filesystem and using the DFS filesystems' 'disk size' entry, instead of just taking the disk image as a disk image.

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.25
(C) Copyright J.G.Harston 1989,2005-2015
>_

Bat
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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Fri Apr 27, 2018 10:24 am

Hi,
Thanks JG. I've no idea if that's happening "behind the scenes" the size difference was the only visible thing to me.
Much the same as I didn't know the Torch system writes to both sides at the same time.
This must be due to the Z80 board as the double drive functions as a normal FDD without it.
Cheers,
Gavin :)

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Lardo Boffin
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Re: A 200Kb into a 199.5Kb pot!

Post by Lardo Boffin » Fri Apr 27, 2018 3:48 pm

As a random aside there are some Torch system discs up for sale on eBay

https://m.ebay.co.uk/itm/ACORN-BBC-MICR ... %7Ciid%3A1

I read a review of the Torch disc pack somewhere and the reviewer said it sound very unhealthy when running DFS discs but sound great when running CPM. I guess there must be something going on in there!
BBC model B 32k issue 4, 16k sideways RAM, Watford 12 ROM board, Viglen twin 40/80 5.25" discs, Acorn 6502 coproc
BBC model B 32k issue 7, turboMMC, Opus Challenger 3 512k, Pi 3 coproc
BBC Master, Datacentre + HDD, pi co-proc

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sbadger
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Re: A 200Kb into a 199.5Kb pot!

Post by sbadger » Sat Apr 28, 2018 7:10 am

Bat wrote:Hi,
I've downloaded some DSD images which I want to use on my BBC B.
I've got a Turbo MMC and the MMB Imager s/w that came with it.
That s/w will split the 400Kb into, wait for it, 2 x 200KB SSDs.
Prefect :)
Now drag and drop them into Imager, no it won't play! :x
The only reason I can see is the Imager reports the "slots" available as 199.5 and I'm trying to drop 200 in there.
Has anyone else come across this?
The DSDs are Torch Z80 system discs if that has any bearing on the stituation?
I don't mind transferring them onto Floppies but I need to get them on the beeb first.
Hope you can help :)
Cheers,
Gavin :)
I had the same problem with mmbimger when testing Kieran's prince of persia, originally it was a dsd.
Once the dsd was split, the mmb tool wouldn't accept it.
What I ended up doing was create a new blank ssd in beebem in drive 0 and insert the oversize ssd in 1 and just *COPY it over, this then allowed me to insert it into the mmb.

stew
So many projects, so little time...

Bat
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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Sat Apr 28, 2018 7:13 am

Thanks Stew.
I'll give that a try later :)

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Re: A 200Kb into a 199.5Kb pot!

Post by Bat » Sat Apr 28, 2018 12:47 pm

Hi,
It looks like Daniel is bang on with this writes both sides at the same time.
Trying Stews method falls flat on it's face in this situation as it chucks out bad program errors every try.
I'm now waiting for several deliveries including a gotek, cables and some original disks as well.
I think my Z80 has the wrong ROM for my 8721 controller so that's another thing to try and figure out...
Once it's all sorted I'll copy the original disks and try the downloads via the gotek and report back :)
Thinking about it I don't know if the gotek will be any use unless you can hot swap FDDs!???
Cheers :)

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danielj
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Re: A 200Kb into a 199.5Kb pot!

Post by danielj » Sat Apr 28, 2018 1:03 pm

You might need to make a custom cable so you can have a 5.25" drive and the gotek connected together and the copy between them. Otherwise the UPURS method will allow you to write directly to floppy. If you're using the gotek there's no real need to use the disc pack (did you get one of the ones from Wakefield?) as it can just be used instead of the floppies.

d.

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