'xemag fat tracks on a c128d'
Author:Nate (guest: search)
Date: Sat, Nov 19th, 2011 @ 22:55 ( . )

I thought it's quite clear why this works in VICE: the track is ordinary DOS format, written across both tracks 35 and 36. VICE automatically aligns tracks to sector 0 (if they are regular DOS) and so the protection sees what it wants when it bumps heads between tracks.

If this was the EA protection or Rapidlok, the track 36 data would not be valid DOS sectors (just plain GCR) and the value would not be correct in a D64 image.


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'xemag fat tracks on a c128d'
Author:hyper active (registered user: 296 posts )
Date: Wed, Nov 07th, 2012 @ 20:06 ( . )

Hello there.
I was lucky enough to get my hands on a xemag game from Microprose, Decision in the Desert.
The fat tracks do read properly on a 128d machine, however, if I make a copy with nib tools and load the game, it dies on my 128d machine but still works on my c64.
I tried an experiment, I measured the size of tracks 35 and 36 from the original, and then measured the size of the backup copy written out by nib tools.
Running NibRead on the master tracks 35 and 36 of the original was 6233 bytes and running NibRead on the copy was 6260 bytes.
The drive motor on My 1541 seems to be permanently stuck on 299.60 rpm and won't go any faster until the drive has been switched on for a while. The slower the drive motor runs, the larger the tracks will get when you write them out.
Using Fast Hackem, I ran their fat track writer on my c128d with built in 1571 drive. The drive seems to run slightly over 300rpm. It took 3 or 4 tries at it but in the end, the protection was able to pass when I loaded the game on both machines. I ran nibread on the backup copy again and this time each track was 6543 bytes long. Only 11 bytes difference, but still enough to pass on both machines.
Moral of the story, If you want to write back a xemag game to play on real hardware, make sure your drive runs at just over 300rpm, then use fast hackem's fat track writer. You may have to repeat this procedure several times and then load your game to see if the protection passes. I tested my copy on 2 xemag games, ocean ranger and decision in the Desert, and it took several goes on my c64 with 1541 to get the fat track check to work. It doesn't pass every time, but it will if you keep trying, as I said earlier, it might take 2 or 3 attempts.


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'xemag fat tracks on a c128d'
Author:hyper active (registered user: 296 posts )
Date: Wed, Nov 07th, 2012 @ 22:35 ( . )

just a short addendum, make sure you make use of the IHS or the timed alignment switch when using nib tools to write out t35 and t36 or else fast hackem's fat track formatter will ruine both tracks.
btw: If I try fast hack em's fat track maker on my c64 with 1541, the second track gets formatted (zeroed out), you may get different results. I had better luck when I used my 128d to do it.


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'xemag fat tracks on a c128d'
Author:hyper active (registered user: 296 posts )
Date: Tue, Nov 13th, 2012 @ 23:13 ( . )

Hmmmmm. This copy of f15 strike eagle uses fat tracks on t6-t7. Unable to get it to pass on my 128d, it has some stuff on it which is overwritten by fast hack'em's fat track formatter, I'll need an original to play with, giving up for now.


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