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Re: Qix - Filecracked! (With Caveats)



On Tuesday, October 23, 2012 4:32:55 PM UTC-5, Steve Nickolas wrote:
> On Tue, 23 Oct 2012, BLuRry wrote:
> 
> 
> 
> > Which screens do you want?  All three loading screens or just the title 
> 
> > that appears after the joystick calibration?
> 
> 
> 
> Far as I know the only problematic one is the title screen (the one with 
> 
> the (C) 1990 Taito America message).
> 
> 
> 
> I can *rip* it, that's not a problem.  The problem is, where is it in 
> 
> memory, why is it getting corrupted?
> 
> 
> 
> -uso.

My guess is that its loaded in a packed form and then depacked into place.  It would make sense considering how fast the other screens are loading.  After the loading screen, I can scan over the memory of page 1 and I see that it is being written by not one opcode/address but several.  It's a depack routine for sure, and it lives somewhere between bd00-beff.  One store operation that writes video is bdf6, another is be37.  Also, there is some sort of data with a regular pattern starting at e900 -- not sure what that is but it's being read by $be51 which is awfully close in proximity to the stuff writing to page1 memory.

Anyway, I have all of the screens ripped but I can't find your email address.  Let me know if you want the ripped data.

In the meantime, I should point out I added a new feature to do this so anyone wanting to dump the active screen to disk will be able to press shift+prntscr or shift+numlock to save the current text/graphics page to disk as a raw memory dump.