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320B Background with 160(A or B) Sprites?


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#1 PacManPlus OFFLINE  

PacManPlus

    River Patroller

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Posted Mon Apr 9, 2018 5:55 PM

Hi guys... running into an issue with my current project.

 

Doesn't One on One use a 320 mode background with 160 mode sprites?  I'd like to do that with my current project, but I don't see a way of doing it.

I really don't want to switch to 160 mode completely...

 

How did they do that?

Thanks,

Bob



#2 Defender_2600 OFFLINE  

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Posted Mon Apr 9, 2018 7:49 PM

Hi Bob, 320 mode + 160 mode would be very interesting ...
 

Anyway, I see a few square pixels in those sprites. Maybe they used the 320C mode sprites with 320A mode background.

 

--------------------------------------------------------------------------------------------------

320C    WM=1,RM1=1,RM0=1
    4 colors from 2 palettes + background & transparent, 2 bits / pixel
D7 D6 D3 D2
 0  0  0  0    BG + BG / transparent
 0  0  0  1    BG + BG / transparent
 0  0  1  0    BG + BG / transparent
 0  0  1  1    BG + BG / transparent
 0  1  0  0    BG + c2
 0  1  0  1    BG + c6
 0  1  1  0    BG + c10
 0  1  1  1    BG + c14
 1  0  0  0    c2 + BG
 1  0  0  1    c6 + BG
 1  0  1  0    c10 + BG
 1  0  1  1    c14 + BG
 1  1  0  0    c2 + c2
 1  1  0  1    c6 + c6
 1  1  1  0    c10 + c10
 1  1  1  1    c14 + c14

-----------------------------------------------------------------------------------------------------

 

maybe they used the 320C mode.PNG

 



#3 Defender_2600 OFFLINE  

Defender_2600

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Posted Mon Apr 9, 2018 8:49 PM

Bob, I don't know if it helps for your project (and maybe I'm missing something) but the 320D mode looks like the equivalent of 320B mode (with 3 colors + background & transparent from 2 palettes) with the advantage that the 320D mode is only 1bpp (as 320A) and therefore approximately equivalent to 160A (cycles consumption).

 

 

sprite data to color mapping.PNG

 



#4 PacManPlus OFFLINE  

PacManPlus

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Posted Tue Apr 10, 2018 7:45 AM

Thank you for that...

 

Although I need more colors than only 2 palettes' worth...  which is why I couldn't go with 320A either...

I may have to convert it to regular 160A mode. :(



#5 Defender_2600 OFFLINE  

Defender_2600

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Posted Tue Apr 10, 2018 8:56 AM

Obviously, I will not ask you questions about this mysterious background... but I wish you all the best in your work. :)



#6 gambler172 OFFLINE  

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Posted Wed Apr 11, 2018 12:00 PM

Hi guys... running into an issue with my current project.
 
Doesn't One on One use a 320 mode background with 160 mode sprites?  I'd like to do that with my current project, but I don't see a way of doing it.
I really don't want to switch to 160 mode completely...
 
How did they do that?
Thanks,
Bob


Hi my friend

cannot wait to se a 1st bin of you new project
Hope you are well.

greetings Walter

#7 EricBall OFFLINE  

EricBall

    Dragonstomper

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Posted Wed Apr 11, 2018 1:00 PM

Doesn't One on One use a 320 mode background with 160 mode sprites?  I'd like to do that with my current project, but I don't see a way of doing it.

I really don't want to switch to 160 mode completely...

 

 

Unfortunately it's not possible to mix 160 and 320 modes on a single line as that is controlled by the Read Mode bits in the CTRL register.  You could change the CTRL register mid-screen using a Display List Interrupt to have different sections of the screen use different resolution.

 

Bob, I don't know if it helps for your project (and maybe I'm missing something) but the 320D mode looks like the equivalent of 320B mode (with 3 colors + background & transparent from 2 palettes) with the advantage that the 320D mode is only 1bpp (as 320A) and therefore approximately equivalent to 160A (cycles consumption).

 

The difference is in how the palette bits are used.  So with 320D if the sprite is palette = x01 then the sprite can use the second set of four pixel duos: BG+C1 / transparent, BG+C3, C2+C1, C2+C3.  So while 320D looks like it has all of the combinations which 320B has, each 320D sprite is restricted to what colors it can use for each pixel.

 

But I'm glad to see someone using my tables!



#8 SlidellMan OFFLINE  

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Posted Wed Apr 11, 2018 6:46 PM

I have to see the potential results of this.






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