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 Post subject: (Another) World Karate Championship image
PostPosted: Mon Oct 01, 2007 9:00 am 
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Joined: Mon Jan 12, 2004 5:01 pm
Posts: 84
Location: Reading UK
Hi all,

Such a cool game this one, known in the UK and Europe as International Karate. I've built this FlashCart image using the VAPI image as reference and actually the loader was quite straight forward after the initial protection checks had been passed, i.e. only the bootstrapper is protected rather than the game itself, or the loading of backdrops.

The game loads in two parts which are then de-compressed post-loading as they use a simple Run-Length encoded system. The first part is the loading screen, which is then displayed, and then the main game part. You may notice too that the colours are all set to black just before the de-compressing.

To make the cart I utilized the decoder leaving it as-is, just replacing the 'Read Sector' call in loader with something to get the same data from the cartridge instead, so loading wizzes along!

Once the game data is loaded, I patch in a new routine over the original code that is used to get the stage background data from the disk when required, again remapping this to obtain data from the cartridge. Luckily the 'One moment' message's display list is in lower memory and so wasn't affected by swapping in the cartridge memory area.

The final cherry-on-the-cake is a couple of patches that get applied if a PAL system is detected. I change the counter timer for 1 second at $3999 from 60 to 50 (i.e. counted during the VBI) and adjust the note-length table (9 bytes at $20D2) by 5/6 so that the tune doesn't sound so slow. :lol:

Enjoy, let me know how you get on.

Mark


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Last edited by Wrathchild on Mon Oct 01, 2007 6:04 pm, edited 1 time in total.

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PostPosted: Mon Oct 01, 2007 10:48 am 
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Joined: Mon Jan 12, 2004 5:01 pm
Posts: 84
Location: Reading UK
Apologies, but I've not done the 'hold down the option key to re-program' support properly and so the cart goes into limbo if you try this. I'll try and post up a patched version today.

[Edit] Looks to be sorted out now, files in the above post replaced.


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PostPosted: Mon Oct 01, 2007 10:23 pm 
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Joined: Fri Aug 15, 2003 5:51 pm
Posts: 75
Location: Tacoma, WA
Very nice, here is a label to print out. :)


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