'Bounty Bob'
Author:Lord Crass (guest: search)
Date: Sat, Mar 03rd, 2012 @ 18:03 ( . )

I took a look at a g64 of Bounty Bob today, but can't get it to read track 1.5 in Vice. It's looking for 5x$77 GCR bytes after a sync mark as the start of sector, but it never finds them, even though they show up in the image file. It keeps finding $52 or $75 after the sync mark, even if I remove those from track with a hex editor.

Does anyone know if Vice handles half-tracks properly? It loads further in HOXS, up to 3 blocks remaining, then dies with a checksum error.

They really pulled out all the stops for this protection:

If the disk isn't write protected, or you have a second drive attached, you'll get a checksum error right away. The sectors are non-standard GCR, extra long, and without standard header. GCR decoding is done on the c64 instead of in the drive. Density is non-standard, and changes when you move to the half-track.

I wonder if it was the game's author, Bill Hogue, who wrote this protection?


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'Bounty Bob'
Author:hyper active (registered user: 296 posts )
Date: Sat, Mar 03rd, 2012 @ 23:35 ( . )

Apparently, it works on a 1541-ultimate so I've been told. There must have been too many issues with drives or computers having troubles with the protection, because they toned it down by releasing a version with simple error checking.
I have a feeling the checksum error on the 3 blocks left to load is because hoxs is running in pal mode and not ntsc, but I could be wrong about that. Peter, do you still have the original disk and if so, can you test it out on a pal machine?
I wonder what kryoflux and markus's flux to g64 tool would do with it?


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sun, Mar 04th, 2012 @ 11:07 ( . )

It doesn't load on 1541U2... Either the original dump or "rigged" version you sent.

Also, the original NTSC release works on a PAL C64. At least the V1.2 original, which is what I own and still has the same halftrack protection.

The protection doesn't appear to read in one continuous motion while stepping like Apple II spiradisk loaders do, it just steps, looks for the marker, reads, steps again. So the timing is probably not super critical.


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'Bounty Bob'
Author:Lord Crass (guest: search)
Date: Sun, Mar 04th, 2012 @ 21:55 ( . )

The g64 I have loads properly on 1541U-1 with the 2.4a firmware, so the image is good. Must be a vice limitation. I'll file a bug report.


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sun, Mar 04th, 2012 @ 23:55 ( . )

That's very strange unless I have a different version of it. 1541u2 here with 2.4ac, fails right away at 75 like VICE.


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'Bounty Bob'
Author:Lord Crass (guest: search)
Date: Mon, Mar 05th, 2012 @ 10:49 ( . )

You made sure to mount the image read-only, and you only have the single drive enabled/attached?

Does it fail with a checksum error, or just hang?


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Fri, Mar 09th, 2012 @ 21:28 ( . )

It works only mounted as read-only.

Which makes me think back- I wonder if this is why the UU custom copier didn't work... I probably never tried write protecting the copy.


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'Bounty Bob'
Author:jerrykurtz (registered user: 4 posts )
Date: Thu, Mar 22nd, 2012 @ 14:56 ( . )

I'm sure I didn't try to write protect my UU copy attempts either.

Interesting to hear that the G64 works with 1541U.


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Mon, Apr 09th, 2012 @ 20:38 ( . )

The SuperCard copier does in fact work if you write protect the copy.

D'oh!

It copied my 1.2 fine with an SC+. No index-hole required- it used timers/custom copier.

So Jim Drew did have it right back in 1989. :)


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'Bounty Bob'
Author:hyper active (registered user: 296 posts )
Date: Tue, Apr 10th, 2012 @ 20:54 ( . )

If Jim Drew could do it with his software in 1989, then it can be done by nibtools in 2012. The old saying "where there's a will there's a way comes to mind


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Tue, Apr 10th, 2012 @ 21:29 ( . )

It's a custom copier, meaning it was created just to write out this one title... which is all it does. It copies a couple of tracks of regular CBM data, then reads in all the halftracks and writes them back out while sweeping the tracks.

It would basically take a custom write routine, and there is no "will" on my part.

I already have a Super-Card+. :)


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'Bounty Bob'
Author:Jim Drew (guest: search)
Date: Tue, May 15th, 2012 @ 01:01 ( . )

Keep in mind that the custom copier just calls routines from the core code. Bounty Bob just requires half tracked writes that are interleaved so that wide head destroys areas not used. There was no real magic to this. Had they used more than 50% of the track (in each half track), it would have not been possible to use a CBM drive to write the data back.


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'Bounty Bob'
Author:Jim Drew (guest: search)
Date: Tue, May 15th, 2012 @ 01:04 ( . )

Oh, and yes you need to write protect ALL copies where the original never had a write protect notch to begin with. I would say that maybe 80% of the commercials games I saw tried to write to the disk as part of their protection check!


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'Bounty Bob'
Author:bluebirdpod (registered user: 28 posts )
Date: Wed, May 16th, 2012 @ 09:21 ( . )

This is true, you need to WP copies or simply make a WP switch mod to your drive. Legacy of the Ancients will write back to the copy if not WP, and it will only load ONE TIME. I thought the copies were going bad, but after WP them all was good. Remember has released this title on one disk side!, wow modern compression techniques are much better than the old ones.


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'Bounty Bob'
Author:jerrykurtz (registered user: 4 posts )
Date: Wed, May 16th, 2012 @ 12:29 ( . )

Shamus formats the disk. I know this from experience as I had a write-protect disable switch on my drive and when I loaded the game, it got formatted. Bye bye original disk. I should have known better...



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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Tue, Apr 10th, 2012 @ 22:28 ( . )

Well, I spoke to soon, again...

The copy does boot all the way up and plays through the intro/high score screen, but it if you try to start a game it locks up.

Mine is V1.2, so maybe it will copy Jerry's earlier original. Who knows...


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'Bounty Bob'
Author:jerrykurtz (registered user: 4 posts )
Date: Tue, Mar 27th, 2012 @ 11:05 ( . )

Now, I'm wondering if a disk from NIBWRITE would load if it were write-protected?


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Tue, Mar 27th, 2012 @ 11:24 ( . )

I can promise you that it won't work!

Nibwrite has no current way to step the head while writing to do those split halftracks. I would have to rewrite all the send routines to incorporate command bytes to do that sort of thing, and even then the timing would be a nightmare to get perfect.

It's possible, and you could do density changes also, but it would likely lose framing unless these operations were done while outputting sync...


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'Bounty Bob'
Author:hyper active (registered user: 296 posts )
Date: Wed, Mar 28th, 2012 @ 09:44 ( . )

If this isn't possible through nibtools, you might be able to remaster it through kryoflux with your flux stream.
Does kryoflux let you write back to disk yet?


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'Bounty Bob'
Author:Lord Crass (guest: search)
Date: Wed, Mar 28th, 2012 @ 21:03 ( . )

The timing's pretty loose, actually. The loader simply steps the half-track and waits forever for a sync mark followed by a series of 5 repeating GCR bytes ($75 for normal tracks, $77 for half-tracks), reads $280 GCR bytes and sending them to the host. It does this 4 times, re-finding the sector header (which only appears once on the track) and skipping X bytes each time to pick up the next part of the sector, for a total sector size of about $A10 bytes including sync mark and the $75/$77 header. GCR decode is all done on the host.

Tracks in this range (1-17) can hold 7692 bytes under normal circumstances. Writing a 2576 byte sector so that it doesn't overlap the neighbouring tracks shouldn't require any special timing other than stepping the head after the end of the previous track's sector and then writing out the next track's sector. Obviously, this does require 8k RAM or a parallel cable due to the sector length.

Of course, it's still quite a bit of work to program and test a completely custom write routine for a single game. I don't think it'd be worth it.


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'Bounty Bob'
Author:Pete Rittwage (registered user: 558 posts )
Date: Sun, Mar 04th, 2012 @ 11:37 ( . )

Hi Stephen,

I was never able to get that "cleaned up" version of BBSB to work, even in HOXS or 1541u2 like you said it did. Did you send me the wrong version?


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'Bounty Bob'
Author:hyper active (registered user: 296 posts )
Date: Sun, Mar 04th, 2012 @ 22:36 ( . )

Ah. thanks for clearing up that confusion, I don't have a 1541-u-x, so I can't test it out for myself.


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'Bounty Bob'
Author:J Achernar (registered user: 36 posts )
Date: Tue, Mar 20th, 2012 @ 19:31 ( . )

No, testing that I have done indicates that WinVICE definitely does NOT handle halftracks correctly. I believe that this is the cause of the weird behavior with EA fat tracks and some other issues.


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'Bounty Bob'
Author:IFWSPS (guest: search)
Date: Thu, Mar 29th, 2012 @ 12:01 ( . )

Vice does not handle half-tracks at all... just take a look at fsimage_read_gcr_image, no half-track is ever loaded.


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