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 Post subject: VFL images
PostPosted: December 29th, 2020, 2:04 am 
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Joined: January 11th, 2007, 12:46 am
Posts: 235
So... almost all the floppy drive image formats used for PC-9801 games are essentially uncompressed and unencrypted... except VFL. Also, almost all are supported by VFIC to some extent... except VFL.

The utility is fortunately still around: https://www.vector.co.jp/soft/dos/util/se012084.html

Sadly, although the documentation hints at a complete file format spec (separately, on NIFTY) I haven't had any luck locating it. The author states the images are compressed using an algorithm borrowed from LHA. Together with being able to use the utility to make test files from known uncompressed images, it's probably quite possible to reverse engineer it.

My question, though, is why? I've only ever seen two games in VFL format:

J. League Professional Soccer 1993
PlayMaker Football

Has anyone seen any more? Do any emulators support this format?


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 Post subject: Re: VFL images
PostPosted: December 30th, 2020, 4:17 pm 
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Joined: September 28th, 2017, 10:51 am
Posts: 8
some files in my HDD

https://mega.nz/file/4J1V1YRC#d8e5lvUca ... BWRtyjpBck


Attachments:
File comment: archived files
FILENAME.zip [2.56 KiB]
Downloaded 55 times
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 Post subject: Re: VFL images
PostPosted: January 12th, 2021, 12:28 am 
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Joined: January 11th, 2007, 12:46 am
Posts: 235
Well, ask and you shall receive. Thanks. Guess I can't weasel out of adding format support now...

Secondary request: Anyone have a NFD r1 image? As far as I can tell, VFIC only makes r0 NFDs.

r0 NFDs start with the 14-byte header: "T98FDDIMAGE.R0" I have the documentation from the author about r1 NFDs (Which should start with "T98FDDIMAGE.R1") but don't have any actual examples. There's a bunch of NFDs in the Neo-Kobe archive, but they're all the standard r0 NFDs, that I've seen.


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 Post subject: Re: VFL images
PostPosted: January 12th, 2021, 2:07 pm 
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Joined: September 28th, 2017, 10:51 am
Posts: 8
[Starcraft] TO-KY-O
[System Sacom] ALL ABOUT MARK FLINT (only ZONE)

https://mega.nz/file/RFkQBYKJ#QjP_IrHM3 ... o3tH0VzAtM

Both are created from the product disk with the -r1d option.

I have fond memories of about 10 years ago, when I wanted to run TO-KY-O on NP2, so I made it support the nfd format.


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 Post subject: Re: VFL images
PostPosted: January 14th, 2021, 12:00 am 
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Joined: January 11th, 2007, 12:46 am
Posts: 235
Wow, thank you!

Those are definitely .r1 files, and they boot up nicely in T98-Next too. I'll see about adding support this weekend, doesn't look like much of a change from the .r0.

NFD isn't ever a multi-disk format, is it? I didn't see anything in the documentation indicating it was.


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 Post subject: Re: VFL images
PostPosted: February 7th, 2021, 4:38 pm 
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Joined: January 11th, 2007, 12:46 am
Posts: 235
So, got the NFD r1 files to work well enough:

Image
Image

Looks like there's some really weird disk geometry on ALL ABOUT MARK FLINT, was that part of the original copy protection that prompted you use to the r1 disk generator?


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 Post subject: Re: VFL images
PostPosted: February 9th, 2021, 1:36 pm 
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Joined: September 28th, 2017, 10:51 am
Posts: 8
The target disk is dumped with KryoFlux and viewed with HxCFloppyEmulator.

Image
Image
Image

...I just realized that there's an error in the dump.


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 Post subject: Re: VFL images
PostPosted: February 13th, 2021, 7:55 pm 
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Joined: January 11th, 2007, 12:46 am
Posts: 235
Hmmm... yes, every one of those oddly-positioned sectors appears to show some kind of read issue:

Image

The data within the sectors appears to be just long repetitions of the same value, as you've shown there, so I suspect they aren't "real" or a valid result.


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