'Non-working images'
Author:Lord Crass (guest: search)
Date: Fri, May 20th, 2011 @ 21:07 ( . )

Frankie Crashed on Jupiter: Protection reads the track 1, sector 20 data block at a non-standard density (%00 instead of %11). The image was read in using the standard density, so the result is garbage. This track needs to be redumped at the lowest density and the sector 20 data block (head block is fine) pasted into the G64 image for it to work in emulation. As for remastering, unless I'm mistaken, mnib can't write multiple densities on a single track yet.

Vixen (PAL) [Martech]: This is Para-Protect V2. Seems to work just fine for me in both NTSC and PAL.


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'Non-working images'
Author:Lord Crass (guest: search)
Date: Sat, May 21st, 2011 @ 14:45 ( . )

Flak [Funsoft 1984]: This awful little protection writes to the disk. It writes to t/s 19/02 and that must succeed or it tries over and over. Then it tries writing to t/s 20/02. This must fail or it tries over and over again.

The protection seems to be based on physically damaged sectors that need to return errors when attempts are made to write to them. I tried erasing the sector header for 20/02 to see if it would fool the protection, but it doesn't work. The protection checks that some of the sector was written (first 6 bytes at the minimum must match).

Unless someone can think of a way to damage the sector in an image to the extent that a U2 write command will only partially work, this won't function in an emulator.

And unless you can physically damage a real disk at the right spot, this won't work remastered either.

On the other hand, it's an easy crack to remove the protection check entirely. There's only one little method used to hide it (check $179F in the main program for the self-modifying code that hides the protection check at $17A2).


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'Non-working images'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sat, May 21st, 2011 @ 15:06 ( . )

Wow, possible laser hole protection? I know it was used on the PC, but this is the first find for the 64.


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'Non-working images'
Author:hyper active (registered user: 296 posts )
Date: Sat, May 21st, 2011 @ 20:03 ( . )

write protect the disk!


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'Non-working images'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sat, May 21st, 2011 @ 20:08 ( . )

But the first check is for that. It must succeed the first time-


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'Non-working images'
Author:Lord Crass (guest: search)
Date: Sat, May 21st, 2011 @ 20:25 ( . )

And after it writes to track 20, it reads it back to verify it. The data it writes is a pseudo-random byte taken from the timer, so it's different each time you load the game.

When it reads it back, at least 6 bytes must match what it thinks it wrote, but the whole sector cannot match. If it does: protection failed.

Anyone here have access to the original disk and can take a look to see what kind of damage exists?


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'Non-working images'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sat, May 28th, 2011 @ 13:47 ( . )

This image came from "HOK". I will ask them.


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'Non-working images'
Author:hyper active (registered user: 296 posts )
Date: Sun, May 29th, 2011 @ 04:54 ( . )

The only way to find out if the disk is really damaged is to first make a nb2 read of it, then format the disk and check to see if the t20s02 is still damaged.


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'Non-working images'
Author:Lord Crass (guest: search)
Date: Sun, May 29th, 2011 @ 10:26 ( . )

I think the damage will be visible on the actual disk. No need to erase the original.


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'Non-working images'
Author:hyper active (registered user: 296 posts )
Date: Mon, May 30th, 2011 @ 16:50 ( . )

I wonder why syncr0l0k wasn't used on other titles. Perhaps some drives couldn't handle it.


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'Non-working images'
Author:Lord Crass (guest: search)
Date: Mon, May 30th, 2011 @ 19:39 ( . )

Expensive, I imagine. And since it's just a one-time check which isn't really integrated into the loader, it's fairly easy to crack. Even in the PC scene, this type of protection was quite rare and you usually only saw it on business apps.


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'Non-working images'
Author:Lord Crass (guest: search)
Date: Sat, May 21st, 2011 @ 20:19 ( . )

Kwik-Write! [Datamost]: Track 15 is non-standard. Only the last sector has a sector header and any data in the data block. This data block is divided into 3 shorter sections by sync marks:

The first section has $45 bytes of data and is written at a non-standard density (%10 instead of %11).

The second section is written at density %01 and $7D bytes are read in.

The third section is written at density %00 and $82 more bytes are read in. The GCR data is then decoded using standard ROM GCR decoding routines.

This track needs to be redumped three more times, at density levels 0, 1, and 2. The data could then be merged into the image for a working G64.

In short, there's all 4 density levels present on this one track (the sector header is written at standard density %11)


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'Non-working images'
Author:hyper active (registered user: 296 posts )
Date: Sun, May 22nd, 2011 @ 18:52 ( . )

nibread -S15 -E15 filename.nb2


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'Non-working images'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sat, May 28th, 2011 @ 13:51 ( . )

I've got an NB2 spin of this disk - sent it your way.


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'Non-working images'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sat, May 28th, 2011 @ 13:42 ( . )

I've requested a redump of Frankie Crashed on Jupiter to NB2 format so we can get it all. The original contributer is still in contact with me from time to time.



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'Non-working images'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sun, Aug 19th, 2012 @ 17:10 ( . )

I have a dump of Frankie at all density levels - I'll send it your way.


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