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Cyanne/easy6502_beams-generated.asm

Last active December 24, 2024 14:06
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Revisions

  1. Cyanne revised this gist Dec 24, 2024. No changes.
  2. Cyanne created this gist Jan 13, 2023.
    199 changes: 199 additions & 0 deletions easy6502_beams-generated.asm
    View file
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    StoreGun:
    ; Line order data starting at $20
    LDA #$00 ; Gun 1 Blue Laser Upper Row
    STA $20
    LDA #$60 ; 2 red
    STA $21
    LDA #$68 ; 3 green
    STA $22
    LDA #$00 ; 4 blue
    STA $23
    LDA #$00 ; Gun 1 Blue Laser Upper Row
    STA $24
    LDA #$60 ; 2 red
    STA $25
    LDA #$68 ; 3 green
    STA $26
    LDA #$68 ; 4 green
    STA $27
    LDA #$00 ; Gun 1 Blue Laser Upper Row
    STA $28
    LDA #$60 ; 2 red
    STA $29
    LDA #$68 ; 3 green
    STA $2a
    LDA #$00 ; 4 blue
    STA $2b
    LDA #$00 ; Gun 1 Blue Laser Upper Row
    STA $2c
    LDA #$60 ; 2 red
    STA $2d
    LDA #$68 ; 3 green
    STA $2e
    LDA #$60 ; 4 red
    STA $2f
    LDA #$08 ; Gun 1 Blue Laser Bottom Row
    STA $30
    LDA #$18 ; 2 red bottom
    STA $31
    LDA #$70 ; 3 green bottom
    STA $32
    LDA #$18 ; 4 red bottom
    STA $33
    LDA #$10 ; Gun 1-4 Body Rows
    STA $34
    STA $35
    STA $36
    STA $37
    LDA #$10 ; Gun 1-4 Body Rows
    STA $38
    STA $39
    STA $3a
    STA $3b
    LDA #$10 ; Gun 1-4 Body Rows
    STA $3c
    STA $3d
    STA $3e
    STA $3f
    LDA #$ff ; Done
    STA $40

    ; Blue Laser Upper Rows ($00-$07)
    LDA #$06
    STA $01
    LDA #$0e
    STA $02
    LDA #$03
    STA $03
    LDA #$01
    STA $04
    LDA #$03
    STA $05
    LDA #$0e
    STA $06
    LDA #$06
    STA $07

    ; Blue Laser Bottom Row ($08-$10)
    LDA #$06
    STA $0a
    LDA #$0e
    STA $0b
    LDA #$01
    STA $0c
    LDA #$0e
    STA $0d
    LDA #$06
    STA $0e

    ; Red Laser Upper Rows ($60-$67)
    LDA #$02
    STA $61
    LDA #$08
    STA $62
    LDA #$07
    STA $63
    LDA #$01
    STA $64
    LDA #$07
    STA $65
    LDA #$08
    STA $66
    LDA #$02
    STA $67

    ; Red Laser Bottom Row ($18-$1f)
    LDA #$02
    STA $1a
    LDA #$08
    STA $1b
    LDA #$01
    STA $1c
    LDA #$08
    STA $1d
    LDA #$02
    STA $1e

    ; Green Laser Upper Rows ($68-$6f)
    LDA #$09
    STA $69
    LDA #$05
    STA $6a
    LDA #$0d
    STA $6b
    LDA #$01
    STA $6c
    LDA #$0d
    STA $6d
    LDA #$05
    STA $6e
    LDA #$09
    STA $6f

    ; Green Laser Upper Rows ($70-$77)
    LDA #$09
    STA $72
    LDA #$05
    STA $73
    LDA #$01
    STA $74
    LDA #$05
    STA $75
    LDA #$09
    STA $76

    ; Gun Body Row ($11-$17)
    LDA #$0b
    STA $11
    LDA #$0b
    STA $12
    LDA #$0c
    STA $13
    LDA #$0c
    STA $14
    LDA #$0f
    STA $15
    LDA #$0f
    STA $16
    LDA #$0c
    STA $17

    DrawGun:
    ; A: Color
    LDX #$00 ; X: Init memory pos reader counter.
    LDY #$00 ; Y: Init screen pos writer counter.
    LDA #$01 ; | Init address $50: Line order counter.
    STA $50 ; |
    ; Address $51: Backup space for Y
    ; | Init address $52: Line progress counter
    DrawGunLoop:
    LDA $00,X ; Read color from address $00+X
    STA $0200,Y ; Store this color to address $0200+Y
    INX
    INC $52
    LDA $52
    CMP #$09 ; Check if line is done
    BEQ AddLine
    INY
    JMP DrawGunLoop

    AddLine:
    LDA #$00 ; \ Reset line progress counter
    STA $52 ; /
    TYA ; \ Backup Y (screen pos counter) into $51
    STA $51 ; /
    LDY $50 ; Load into Y Line Order Counter ($50)
    ; Re-set memory read position X by reading the line order data starting at $20
    LDA $0020,Y ; Y now being the line order count
    CMP #$ff
    BEQ Exit
    TAX ; Give the resulting reset point to X
    INY ; Increment line order counter
    STY $50 ; Store it back into $50
    LDY $51 ; Recover backup of Y to Y (screen pos counter)
    JMP DrawGunLoop

    Exit:
    BRK