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2600 Rom Comparisions and Dumps


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#1251 Thomas Jentzsch OFFLINE  

Thomas Jentzsch

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Posted Wed Jun 7, 2017 2:57 AM

I believe that, in case of Pitfall II, the cause of most of the graphic changes is SECAM compatibility.

Interesting theory. It would explain less color luminosity differences, but not completely wrong PAL colors (e.g. in PAL Pole Position, the curbs are brown ($44). They could easily be red ($64) and still look OK in SECAM).

It would be nice to find some clear evidence or first hand information.

#1252 alex_79 OFFLINE  

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Posted Wed Jun 7, 2017 5:59 AM

Interesting theory. It would explain less color luminosity differences, but not completely wrong PAL colors (e.g. in PAL Pole Position, the curbs are brown ($44). They could easily be red ($64) and still look OK in SECAM).

Yeah, the lousy conversion argument still stands. I think the SECAM compatibility is an additional cause that explains some programming choices in some of the Atari and Activision PAL conversions of the early '80s. Later, the 2600 junior and 7800 were available in France in PAL format (or RGB with PAL palette), and support for SECAM was abandoned.
 

It would be nice to find some clear evidence or first hand information.

I'd like that too.
 



#1253 Tempest OFFLINE  

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Posted Wed Jun 7, 2017 7:20 AM

Why is the boulder behind Quick Claw missing?



#1254 Thomas Jentzsch OFFLINE  

Thomas Jentzsch

    Thrust, Jammed, SWOOPS!, Boulder Dash, THREE·S, Star Castle

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Posted Wed Jun 7, 2017 7:30 AM

Must be an initialization error. If you run to the next screen and back, the boulder is there. And even you if hack the game and make Harry start left of Quickclaw, he cannot exit to the left.

Edited by Thomas Jentzsch, Wed Jun 7, 2017 7:33 AM.


#1255 alex_79 OFFLINE  

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Posted Tue Jun 13, 2017 1:27 PM

Activision Bridge PAL:
bridge1.jpeg

bridge2.jpeg

 

Attached File  Bridge_PAL.bin   4KB   8 downloads

 

Bridge_PAL_1.png

 

Only 5 bytes differ from the NTSC "fixed" version.

PAL on the left, NTSC on the right:

01AD 40 23  overscan TIMER
02E5 47 2A  vblank TIMER
0FD8 64 44  diamonds COLOR
0FD9 64 44  hearts COLOR
0FDB B2 92  background COLOR


The pirate PAL rom (208 in 1 cartridge) that was already dumped, has slightly higher timer values (frames are 316 lines) and keeps the color values of the NTSC versions (which by chance look quite right, anyway).

original PAL on the left, pirate PAL on the right:

01AD 40 43
02E5 47 4A
0FD8 64 44
0FD9 64 44
0FDB B2 92


 



#1256 Rom Hunter OFFLINE  

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Posted Tue Jun 13, 2017 2:59 PM

Many thanks, Alex!

I'm glad the cart worked 100%.

Will add the ROM right away.

8)






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