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#110449 - 07/29/17 04:47 PM Re: cpc 6128 - demo [Re: Breiztiger]  
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crazyc Online content
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I've seen two cases where a dumped image is too large because of invalid sectors wedged into the gaps. They will then work on emulators that aren't picky about track sizes.

#110450 - 07/29/17 04:53 PM Re: cpc 6128 - demo [Re: Breiztiger]  
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Haze Offline
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are you sure they're invalid sectors, not there because that's how the format represents copy protected tracks? I think they include multiple copies of weak sectors so that the emulator can read a different copy each time and gets different ones if seeking forward / back the first time (unless i'm thinking of a different format)

I know what was meant to be a simple format was extended to support the most common cpc disk protections at least.

Last edited by Haze; 07/29/17 04:54 PM.
#110451 - 07/29/17 05:18 PM Re: cpc 6128 - demo [Re: Breiztiger]  
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Breiztiger Offline
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hi

it's a proper dump that i have make myself with a kryoflux

it's a edsk format not dsk witch is old and not use today with new dump as a make

i have also create a editor for Amstrad dsk as i can say this dsk is good

just it has all gaps for each sector and the track 0 length is 5805 bytes not only 4608 bytes (9x512)

it is not copy protected just full dump with gaps

Last edited by Breiztiger; 07/29/17 05:20 PM.
#110453 - 07/30/17 09:12 AM Re: cpc 6128 - demo [Re: Breiztiger]  
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Bavarese Offline
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There is a hard limit of 100.000 bytes i also encountered:

Code
build_pc_track_mfm(track, side, image, 100000, tr.number_of_sector, sects, tr.gap3_length);


If you just sampled more data than the 'dsk_dsk' routine can handle (no copy protection assumed), it should be possible to cut the gaps (automagically or in a disk editor).

Olivier Galibert is the author of the 'dsk_dsk' importer. Kevin Thacker and Barry Rodewald wrote the Amstrad emulation.

You might have luck contacting Olivier Galibert in your own tongue - or just upload the image so folks can have a look.

[EDIT: to increase the limit is not a good idea. Upload to Dropbox or a good free file hoster and post the link here]

Last edited by Bavarese; 07/30/17 12:06 PM.
#110454 - 07/30/17 10:19 AM Re: cpc 6128 - demo [Re: Breiztiger]  
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Breiztiger Offline
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i have try to change 100000 to 200000 but not working

https://1drv.ms/f/s!AsnNM-hItJM6ipUvAfhUtZMoMg2zQQ


Last edited by Breiztiger; 07/30/17 01:09 PM.
#110467 - 08/01/17 09:15 AM Re: cpc 6128 - demo [Re: Breiztiger]  
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Bavarese Offline
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The disks you uploaded in the previous post had FDC errors and appear to have a very non-standard track layout.
They also utilise increased track densities to cram more data on a floppy than usual.

You can verify that with 'Disk Image Manager' (which is freely available).

To the right (green) is a PD disk i downloaded for verification, with 40 properly formated tracks.

[img]https://www.dropbox.com/s/nf9vyg8lanozhdt/Non_standard_or_copy_protected_disk.jpg?dl=0[/img]

Are you trying to work with a damaged disk - or import a copy protected disk?

The current importer for *.DSK seems a bit ill prepared for density variations. I am by far no CPC expert, though. smile

Last edited by Bavarese; 08/01/17 10:21 AM.
#110470 - 08/01/17 05:51 PM Re: cpc 6128 - demo [Re: Breiztiger]  
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Breiztiger Offline
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i can confirm that this disk is almost normal

http://www.cpc-power.com/SectorView.php?fiche=1058&slot=10&rang=0 click on map tab

no track density changed

just track 3 is unformat

and protected track is track 4 (sector size 4 but only have 100 bytes length take st1 and st2 number &20 checksum error)

this edsk is a good dump from a working real disk

all cpc emulator like caprice, sugarbox, and other play good with this game (Harry and Harry from ere informatique)


Last edited by Breiztiger; 08/01/17 05:59 PM.
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