349 lines
27 KiB
Groff
349 lines
27 KiB
Groff
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| For those of you who don't know how the SNES does do it's graphics, it |
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| uses tiles (surprise surprise!). |
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| |
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| There are different MODEs on the SNES; the most famous being MODE 7. |
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| Most people think that $2106 (Screen Pixelation: Look in SNES.1 for an ex- |
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| planation on this register) is MODE 7. *** THIS IS NOT MODE 7!!! ***. |
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| So, the next time the pixels get really "big" (almost making them |
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| look like IBM-clone 320x200x256 MODE 13h graphics), and your friend says |
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| "WOW! MODE 7 is really awesome," punch him/her in the nose for me. Just |
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| joking. :-) |
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| |
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| Also, another thing I should mention: Bitplanes are not equal the planes, |
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| atleast in my document. Planes are like overlayed-screens; you can scroll |
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| a plane, but not a bitplane. Bitplanes are put ONTO a plane... |
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| |
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| I'll be explaining MODE 1. MODE 7 I don't know, and I don't plan on learn- |
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| ing about it anytime in the near future. Sorry to those who wanted MODE 7 |
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| documentation! :-( Look elsewhere. |
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|MODE #/Playfields MaxColour/Tile Palettes Colours |
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|----------------------------------------------------------------------------|
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|0 4 4 8 32 |
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|1 3 16/16/4 (HUH?) 8 128 |
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| |
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| MODE 0 is good for geometric shapes (if you were going to rotate a wire- |
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| frame cube, or something like that), basic star scrolls, or a very 'bland' |
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| text scroller... it's pretty cool and doesn't take up much space. :-) |
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| I'm going to explain MODE 1, since MODE 0 is the same thing but with less |
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| bitplanes. :-) |
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| |
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| MODE 1 is really best for things; detailed star scrolls, text scrollers, |
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| geometric shapes, and filled objects. It's the most common used MODE in |
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| the professional SNES programming world. |
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| |
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| What you need is 4 bitplanes of data; You don't HAVE to use all 4 bit- |
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| planes; you can use 1 bitplane if you want, but you only get 16 colours. |
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| |
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| You also need a plane map: You can't just have the predefined graphics, |
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| and that's it: You need to "setup the plane" to tell it what tile goes |
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| where. For demonstration purposes, i'll use code to explain it... |
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|----------------------------------------------------------------------------|
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| The "lda #$0000 tcd" transfers the DP location pointer to where the |
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| so-called 'scratchpad RAM' is. This makes things go much faster, because |
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| DP is always faster than normal RAM (yay for DP!) |
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| The other part defines the location of the data for where the binary or |
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| image data is into two DP locations: font and font2. |
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|----------------------------------------------------------------------------|
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| font equ $00 ; Direct page equates. |
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| font2 equ font+1 |
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| |
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| sei |
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| phk |
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| plb |
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| xce |
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| rep #$30 |
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| lda #$0000 |
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| tcd |
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| lda #charset |
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| sta font |
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| lda #charset2 |
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| sta font2 |
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|----------------------------------------------------------------------------|
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| The following code tells the SNES where the actual data is in VRAM memory. |
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|----------------------------------------------------------------------------|
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| lda #$10 ; Plane 0 text @VRAM location $1000. |
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| sta $2107 |
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| lda #$02 ; Tiles for Plane 0 @VRAM $2000. |
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| sta $210b |
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|----------------------------------------------------------------------------|
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| The following code actually MOVES the data in the binary/image into the |
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| SNESs' VRAM. |
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|----------------------------------------------------------------------------|
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| sep #$20 |
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| ldx #$2000 ; This puts the data sent thru $2118 and |
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| stx $2116 ; $2119 into VRAM location $2000. |
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| ldy #$0000 |
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|- lda (font),y ; ...Get bitplane 0 data (font)... |
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| sta $2118 ; ...and store it in bitplane 0... |
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| lda (font2),y ; ...Get bitplane 1 data (font2)... |
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| sta $2119 ; ...and story it in bitplane 1... |
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| stz $2118 ; I don't use bitplane 2 and 3, so I put |
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| stz $2119 ; zeros for their data. You could put |
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| iny ; more font data here if you wanted. |
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| cpy #$0200 |
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| bne - |
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| |
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| ldx #$1000 ; Put the data sent thru $2118 and $2119 |
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| stx $2116 ; into VRAM location $1000. |
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| ldx #$0000 |
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|- lda Text,x ; Get the character from Text... Then AND |
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| and #$3f ; #$3f it 'cuz I only define the first 8 |
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| sta $2118 ; bits for a character: I don't care for |
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| stz $2119 ; the rest... Check near the end of this |
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| inx ; file for an explanation on why I just |
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| cpx #$0400 ; clear them. |
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| bne - |
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|----------------------------------------------------------------------------|
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| Here's the actual data names (charset, charset2, and Text). My new source |
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| has them in dcb % statements to make the font more readable; the first |
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| time I did this, I had to convert the binary stuff I wrote on paper into |
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| hex, then put them into decent hex statements in an orderly fashion! :-( |
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|----------------------------------------------------------------------------|
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|charset |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'@' |
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| dcb $00,$3c,$66,$7e,$66,$66,$66,$00 ;'A' |
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| dcb $00,$7c,$66,$7c,$66,$66,$7c,$00 ;'B' |
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| dcb $00,$3c,$66,$60,$60,$66,$3c,$00 ;'C' |
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| dcb $00,$78,$6c,$66,$66,$6c,$78,$00 ;'D' |
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| dcb $00,$7e,$60,$78,$60,$60,$7e,$00 ;'E' |
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| dcb $00,$7e,$60,$78,$60,$60,$60,$00 ;'F' |
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| dcb $00,$3c,$66,$60,$6e,$66,$3c,$00 ;'G' |
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| dcb $00,$66,$66,$7e,$66,$66,$66,$00 ;'H' |
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| dcb $00,$3c,$18,$18,$18,$18,$3c,$00 ;'I' |
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| dcb $00,$1e,$0c,$0c,$0c,$6c,$38,$00 ;'J' |
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| dcb $00,$6c,$78,$70,$78,$6c,$66,$00 ;'K' |
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| dcb $00,$60,$60,$60,$60,$60,$7e,$00 ;'L' |
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| dcb $00,$63,$77,$7f,$6b,$63,$63,$00 ;'M' |
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| dcb $00,$66,$76,$7e,$7e,$6e,$66,$00 ;'N' |
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| dcb $00,$3c,$66,$66,$66,$66,$3c,$00 ;'O' |
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| dcb $00,$7c,$66,$66,$7c,$60,$60,$00 ;'P' |
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| dcb $00,$3c,$66,$66,$66,$3c,$0e,$00 ;'Q' |
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| dcb $00,$7c,$66,$66,$7c,$6c,$66,$00 ;'R' |
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| dcb $00,$3e,$60,$3c,$06,$66,$3c,$00 ;'S' |
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| dcb $00,$7e,$18,$18,$18,$18,$18,$00 ;'T' |
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| dcb $00,$66,$66,$66,$66,$66,$3c,$00 ;'U' |
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| dcb $00,$66,$66,$66,$66,$3c,$18,$00 ;'V' |
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| dcb $00,$63,$63,$6b,$7f,$77,$63,$00 ;'W' |
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| dcb $00,$66,$3c,$18,$3c,$66,$66,$00 ;'X' |
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| dcb $00,$66,$66,$3c,$18,$18,$18,$00 ;'Y' |
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| dcb $00,$7e,$0c,$18,$30,$60,$7e,$00 ;'Z' |
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| dcb $08,$00,$00,$00,$00,$00,$00,$00 ;'[' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'\' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;']' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'^' |
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| dcb $00,$08,$00,$00,$00,$00,$00,$00 ;'_' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;' ' |
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| dcb $00,$7E,$7E,$3C,$18,$00,$18,$00 ;'!' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'"' |
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| dcb $80,$80,$80,$80,$80,$80,$80,$80 ;'#' |
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| dcb $FC,$FE,$FF,$F7,$F7,$FF,$FE,$FC ;'$' |
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| dcb $3E,$42,$4E,$5C,$5C,$4E,$42,$3E ;'%' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$01 ;'&' |
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| dcb $00,$00,$00,$07,$00,$00,$00,$00 ;''' |
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| dcb $00,$04,$08,$08,$08,$08,$04,$00 ;'(' |
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| dcb $00,$20,$10,$10,$10,$10,$20,$00 ;')' |
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| dcb $08,$08,$08,$F8,$08,$08,$08,$08 ;'*' |
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| dcb $10,$10,$10,$1F,$10,$10,$10,$10 ;'+' |
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| dcb $10,$10,$20,$C0,$00,$00,$00,$00 ;',' |
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| dcb $00,$00,$00,$FF,$00,$00,$00,$00 ;'-' |
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| dcb $00,$00,$00,$00,$00,$18,$18,$00 ;'.' |
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| dcb $00,$00,$00,$FF,$80,$80,$80,$80 ;'/' |
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| dcb $00,$3c,$66,$6e,$76,$66,$3c,$00 ;'0' |
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| dcb $00,$18,$38,$18,$18,$18,$7e,$00 ;'1' |
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| dcb $00,$7c,$06,$0c,$30,$60,$7e,$00 ;'2' |
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| dcb $00,$7e,$06,$1c,$06,$66,$3c,$00 ;'3' |
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| dcb $00,$0e,$1e,$36,$7f,$06,$06,$00 ;'4' |
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| dcb $00,$7e,$60,$7c,$06,$66,$3c,$00 ;'5' |
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| dcb $00,$3e,$60,$7c,$66,$66,$3c,$00 ;'6' |
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| dcb $00,$7e,$06,$0c,$0c,$0c,$0c,$00 ;'7' |
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| dcb $00,$3c,$66,$3c,$66,$66,$3c,$00 ;'8' |
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| dcb $00,$3c,$66,$3e,$06,$66,$3c,$00 ;'9' |
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| dcb $00,$00,$00,$03,$04,$08,$08,$08 ;':' |
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| dcb $00,$80,$80,$F0,$80,$80,$00,$00 ;';' |
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| dcb $80,$80,$80,$FF,$00,$00,$00,$00 ;'<' |
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| dcb $00,$00,$00,$C0,$20,$10,$10,$10 ;'=' |
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| dcb $08,$08,$04,$03,$00,$00,$00,$00 ;'>' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'?' |
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|charset2 |
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| dcb $00,$3C,$4E,$5E,$5E,$40,$3C,$00 ;'@' |
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| dcb $00,$3c,$66,$7e,$66,$66,$66,$00 ;'A' |
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| dcb $00,$7c,$66,$7c,$66,$66,$7c,$00 ;'B' |
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| dcb $00,$3c,$66,$60,$60,$66,$3c,$00 ;'C' |
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| dcb $00,$78,$6c,$66,$66,$6c,$78,$00 ;'D' |
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| dcb $00,$7e,$60,$78,$60,$60,$7e,$00 ;'E' |
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| dcb $00,$7e,$60,$78,$60,$60,$60,$00 ;'F' |
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| dcb $00,$3c,$66,$60,$6e,$66,$3c,$00 ;'G' |
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| dcb $00,$66,$66,$7e,$66,$66,$66,$00 ;'H' |
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| dcb $00,$3c,$18,$18,$18,$18,$3c,$00 ;'I' |
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| dcb $00,$1e,$0c,$0c,$0c,$6c,$38,$00 ;'J' |
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| dcb $00,$6c,$78,$70,$78,$6c,$66,$00 ;'K' |
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| dcb $00,$60,$60,$60,$60,$60,$7e,$00 ;'L' |
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| dcb $00,$63,$77,$7f,$6b,$63,$63,$00 ;'M' |
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| dcb $00,$66,$76,$7e,$7e,$6e,$66,$00 ;'N' |
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| dcb $00,$3c,$66,$66,$66,$66,$3c,$00 ;'O' |
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| dcb $00,$7c,$66,$66,$7c,$60,$60,$00 ;'P' |
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| dcb $00,$3c,$66,$66,$66,$3c,$0e,$00 ;'Q' |
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| dcb $00,$7c,$66,$66,$7c,$6c,$66,$00 ;'R' |
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| dcb $00,$3e,$60,$3c,$06,$66,$3c,$00 ;'S' |
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| dcb $00,$7e,$18,$18,$18,$18,$18,$00 ;'T' |
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| dcb $00,$66,$66,$66,$66,$66,$3c,$00 ;'U' |
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| dcb $00,$66,$66,$66,$66,$3c,$18,$00 ;'V' |
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| dcb $00,$63,$63,$6b,$7f,$77,$63,$00 ;'W' |
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| dcb $00,$66,$3c,$18,$3c,$66,$66,$00 ;'X' |
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| dcb $00,$66,$66,$3c,$18,$18,$18,$00 ;'Y' |
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| dcb $00,$7e,$0c,$18,$30,$60,$7e,$00 ;'Z' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'[' |
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| dcb $09,$09,$00,$00,$00,$00,$00,$00 ;'\' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;']' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'^' |
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| dcb $00,$08,$00,$00,$00,$00,$00,$00 ;'_' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;' ' |
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| dcb $00,$7E,$7E,$3C,$18,$00,$18,$00 ;'!' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'"' |
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| dcb $80,$80,$80,$80,$80,$80,$80,$80 ;'#' |
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| dcb $FC,$FE,$FF,$F7,$F7,$FF,$FE,$FC ;'$' |
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| dcb $3E,$42,$4E,$5C,$5C,$4E,$42,$3E ;'%' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$01 ;'&' |
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| dcb $00,$00,$00,$07,$00,$00,$00,$00 ;''' |
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| dcb $00,$04,$08,$08,$08,$08,$04,$00 ;'(' |
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| dcb $00,$20,$10,$10,$10,$10,$20,$00 ;')' |
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| dcb $08,$08,$08,$F8,$08,$08,$08,$08 ;'*' |
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| dcb $10,$10,$10,$1F,$10,$10,$10,$10 ;'+' |
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| dcb $10,$10,$20,$C0,$00,$00,$00,$00 ;',' |
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| dcb $00,$00,$00,$FF,$00,$00,$00,$00 ;'-' |
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| dcb $00,$00,$00,$00,$00,$18,$18,$00 ;'.' |
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| dcb $00,$00,$00,$FF,$80,$80,$80,$80 ;'/' |
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| dcb $00,$3c,$66,$6e,$76,$66,$3c,$00 ;'0' |
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| dcb $00,$18,$38,$18,$18,$18,$7e,$00 ;'1' |
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| dcb $00,$7c,$06,$0c,$30,$60,$7e,$00 ;'2' |
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| dcb $00,$7e,$06,$1c,$06,$66,$3c,$00 ;'3' |
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| dcb $00,$0e,$1e,$36,$7f,$06,$06,$00 ;'4' |
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| dcb $00,$7e,$60,$7c,$06,$66,$3c,$00 ;'5' |
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| dcb $00,$3e,$60,$7c,$66,$66,$3c,$00 ;'6' |
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| dcb $00,$7e,$06,$0c,$0c,$0c,$0c,$00 ;'7' |
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| dcb $00,$3c,$66,$3c,$66,$66,$3c,$00 ;'8' |
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| dcb $00,$3c,$66,$3e,$06,$66,$3c,$00 ;'9' |
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| dcb $00,$00,$00,$03,$04,$08,$08,$08 ;':' |
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| dcb $00,$80,$80,$F0,$80,$80,$00,$00 ;';' |
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| dcb $80,$80,$80,$FF,$00,$00,$00,$00 ;'<' |
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| dcb $00,$00,$00,$C0,$20,$10,$10,$10 ;'=' |
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| dcb $08,$08,$04,$03,$00,$00,$00,$00 ;'>' |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'?' |
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| |
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|TEXT dcb " THIS IS YOUR ENTIRE SCREEN " |
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| dcb " HERE... IF YOU REMOVE ONE OF " |
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| dcb " THE LINES WHICH IS BLANK, THE " |
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| dcb " SCREEN ENDS UP BEING FUNKY " |
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| dcb " DOWN AT THE BOTTOM OF THE " |
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| dcb " SCREEN. " |
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| dcb " " |
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| dcb " SO MAKE SURE YOU ALWAYS LEAVE " |
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| dcb " ALL OF THIS TEXT THINGS IN! " |
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| dcb " " |
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| dcb " " |
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| dcb " " |
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| dcb " YOSHI THE DINO " |
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| dcb " " |
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| dcb " " |
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| dcb " " |
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| dcb " " |
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| dcb " " |
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| dcb " " |
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| dcb "********************************" |
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|----------------------------------------------------------------------------|
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| Well there's some code for those whom want to rip it :-). I hope I haven't |
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| confused you yet: If I have, go back and re-read the code. I've been work- |
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| ing with the 65c816 based CPU for awhile, so I understand a little more |
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| than a newbie. :-) |
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| You're probably wondering how the heck the following line ends up being an |
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| "@" on your TV or monitor: |
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| charset |
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| dcb $00,$00,$00,$00,$00,$00,$00,$00 ;'@' |
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|charset2 |
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| dcb $00,$3C,$4E,$5E,$5E,$40,$3C,$00 ;'@' |
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| |
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| Convert the above hex-values into binary. Consider each byte (each new $xx |
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| statement) a new pixel line. Tile size in thie case is 8x8. |
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| %00000000 = $00 |
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| %00000000 = $00 This is charset |
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| %00000000 = $00 |
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| %00000000 = $00 |
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| %00000000 = $00 |
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| %00000000 = $00 |
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| %00000000 = $00 |
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| %00000000 = $00 |
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| |
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| %00000000 = $00 |
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| %00111100 = $3C This is charset2 |
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| %01001110 = $4E |
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| %01011110 = $5E |
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| %01011110 = $5E |
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| %01000000 = $40 |
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| %00111100 = $3C |
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| %00000000 = $00 |
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| |
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| See the AT symbol in charset2? This font took me hours by hand, drawing it |
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| in binary-statements, so... |
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| You're probably now asking: "Well, that tells me how to define where a |
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| pixel IS, but how do I define it's colour?" |
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| |
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| If you have a 0 for bitplane 0, a 0 for bitplane 1, a 0 for bitplane 2, |
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| and a 0 for bitplane 3, you get color #0; eg.: |
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| 0000 = Color #0 |
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| ||||___________Bitplane 0 |
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| |||__________Bitplane 1 |
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| ||_________Bitplane 2 |
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| |________Bitplane 3 |
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| |
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| So, now, think about a 0 for bitplane 0, a 1 for bitplane 1 and 2, and a 0 |
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| for bitplane 3: |
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| 0110 = Color #6 |
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| ||||___________Bitplane 0 |
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| |||__________Bitplane 1 |
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| |_________Bitplane 2 |
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|
| |________Bitplane 3 |
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| |
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|
| Keep in mind, this is the best explanation i've ever seen done about SNES |
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|
|
| pixel color definition. Until I see better, I'd have to say this is the |
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| best it's gonna get. |
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|
| The result above gives you the color # per pixel; it's interesting. It's |
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| an "overlay" method, so-to-speak. |
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| |
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|
| I mentioned in the source listed above that you should check near the end |
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|
| of this file for information on why I "stz $2119". |
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|
|
| Well, here's why: |
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|
| The bits in the tile-data are fairly "silly," atleast to me. The bits for |
|
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| the actual character take up the first 10 bits; the other 6 are for 'fun'. |
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|
|
| y: Flip the tile vertically. yxPcccNN | NNNNNNNN |
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|
| x: Flip the tile horizontally. |
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|
| P: Priority bit (if it's set to 1, tile shows thru from plane 1 to 0). |
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|
| c: Pallete # (0-7). |
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|
| N: Character-bits themselves. |
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| |
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|
| So, I STZ there: Yes, I leave the top bits "unset", which means you COULD |
|
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|
| get messed up data; but as far as I have checked, the SNES has zeros in |
|
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|
|
| memory when you power it: So, the bits I don't zero out should be zero |
|
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|
|
| anyways! If you want to set them, feel free to do so... The resutls of |
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||
|
|
| flipping Y and X are sortof fun to play with. "To read this scroller, you |
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||
|
|
| must stand on your head." |
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|
|
----------------------------------------------------------------------------
|