Current ROM Progress

;----------------------------------------------------------------
; DEFINES
;----------------------------------------------------------------
PPU_CTRL                = $2000
PPU_MASK                = $2001
PPU_STATUS              = $2002
PPU_OAM_ADDR            = $2003
PPU_OAM_DATA            = $2004
PPU_SCROLL              = $2005
PPU_ADDRESS             = $2006
PPU_DATA                = $2007
DMC_REG_1               = $4010
PPU_OAM_DMA             = $4014
CONTROLLER_1            = $4016
CONTROLLER_2            = $4017
;----------------------------------------------------------------
; constants
;----------------------------------------------------------------

frameCounter            = $0900
playerSpeed             = $0500

PRG_COUNT               = 1 ;1 = 16KB, 2 = 32KB
MIRRORING               = %0001 ;%0000 = horizontal, %0001 = vertical, %1000 = four-screen

;----------------------------------------------------------------
; variables
;----------------------------------------------------------------

   .enum $0000

   ;NOTE: declare variables using the DSB and DSW directives, like this:

   ;MyVariable0 .dsb 1
   ;MyVariable1 .dsb 3

   .ende

   ;NOTE: you can also split the variable declarations into individual pages, like this:

   ;.enum $0100
   ;.ende

   ;.enum $0200
   ;.ende


;----------------------------------------------------------------
; iNES header
;----------------------------------------------------------------

   .db "NES", $1a ;identification of the iNES header
   .db PRG_COUNT ;number of 16KB PRG-ROM pages
   .db $01 ;number of 8KB CHR-ROM pages
   .db $00|MIRRORING ;mapper 0 and mirroring
   .dsb 9, $00 ;clear the remaining bytes

;----------------------------------------------------------------
; program bank(s)
;----------------------------------------------------------------

   .base $10000-(PRG_COUNT*$4000)

palettes:
    .db $0f,$00,$10,$30,$0f,$01,$12,$38,$0f,$04,$15,$26,$0f,$0f,$2d,$3d
    .db $0f,$00,$10,$30,$0f,$01,$12,$38,$0f,$04,$15,$26,$0f,$0f,$2d,$3d

    ;  VERT-TILE-ATTR-HORIZ
player_mSPRITE:
    .db $80, $00, $00, $80
    .db $80, $01, $00, $88
    .db $80, $02, $00, $90
    .db $88, $10, $00, $80
    .db $88, $11, $00, $88
    .db $88, $12, $00, $90

Reset:
    SEI             ;Disable IRQs
    CLD             ;Disable Decimal mode

    LDX #$40        ;Hex for binary flag 0100 0000 which inhibits and clears the frame interrupt flag
    STX $4017       ;Disable Audio Processor frame IRQ

    LDX #$FF        ;Load 255 to stack
    TXS             ;-----------------
    INX             ;Overflow X to 0
    STX PPU_CTRL    ;Set PPU CTRL flags to 0
    STX PPU_MASK    ;Set PPU Mask flags to 0
    STX DMC_REG_1       ;Set DMC flags to 0
   ;NOTE: initialization code goes here

VBlankWait1:
    BIT PPU_STATUS
    BPL VBlankWait1

ClearMemory:
    LDA #$00
    STA $0000, x    ;Basically this clears out every RAM register by loading in 0
    STA $0100, x
    STA $0300, x
    STA $0400, x
    STA $0500, x
    STA $0600, x
    STA $0700, x
    LDA #$FE
    STA $0200, x
    INX
    BNE ClearMemory

VBlankWait2:
    BIT PPU_STATUS
    BPL VBlankWait2

;This code tells the PPU to start accepting Background Palette data.


InitPalettes:
    LDA PPU_STATUS  ;Reads the PPU Status to reset the high/low latch

    LDA #$3F        ;Write the high byte of the PPU address
    STA PPU_ADDRESS

    LDA #$00        ;Write the low byte of the PPU address
    STA PPU_ADDRESS

    LDX #$00

LoadPalettes:
    LDA palettes, x ;Load the current index of the palette using X as the index number;
    STA PPU_DATA    ;Write the current index to the PPU Memory;
    INX             ;Increment the index
    CPX #$20        ;Compare the index against hex value 20(decimal: 32)
    BNE LoadPalettes;Continue the loop until the index until the index hits hex 20(decimal: 32)

InitSprites:
    LDX #$00

LoadSprites:
    LDA player_mSPRITE, x   ;Same deal as the palette, but this time for the metasprite
    STA $0200, x            ;Increment through each bit of RAM
    INX
    CPX #$18
    BNE LoadSprites

PPUStart:
    LDA #%10000000
    STA PPU_CTRL

    LDA #%00010000
    STA PPU_MASK

    LDX #$00

Update:
    JMP Update

NMI:
    LDA #$00        ;OAM low read write address value
    STA PPU_OAM_ADDR;Set the low byte (00) of the RAM address

    LDA #$02        ;OAM high address value
    STA PPU_OAM_DMA ;Set the high byte (02) of the RAM address, start the transfer

    INC frameCounter

   ;NOTE: NMI code goes here

LatchController:
    LDA #$01
    STA CONTROLLER_1
    LDA #$00
    STA CONTROLLER_1

;==================================
;READ A BUTTON
;==================================
ReadContA:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContADone

ReadContADone:

;==================================
;READ B BUTTON
;==================================
ReadContB:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContBDone

ReadContBDone:

;==================================
;READ SELECT BUTTON
;==================================
ReadContSelect:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContSelectDone

ReadContSelectDone:

;==================================
;READ START BUTTON
;==================================

ReadContStart:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContStartDone

ReadContStartDone:

;==================================
;READ UP BUTTON
;==================================
ReadContUp:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContUpDone

ReadContUpDone:

;==================================
;READ DOWN BUTTON
;==================================

ReadContDown:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContDownDone

ReadContDownDone:

;==================================
;READ LEFT BUTTON
;==================================

ReadContLeft:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContLeftDone

    LDA $0203
    SEC
    SBC #$01
    STA $0203

    LDA $0207
    SEC
    SBC #$01
    STA $0207

    LDA $020B
    SEC
    SBC #$01
    STA $020B

    LDA $020F
    SEC
    SBC #$01
    STA $020F

ReadContLeftDone:

;==================================
;READ RIGHT BUTTON
;==================================

ReadContRight:
    LDA CONTROLLER_1
    AND #%00000001
    BEQ ReadContRightDone

    LDA $0203
    CLC
    ADC #$01
    STA $0203

    LDA $0207
    CLC
    ADC #$01
    STA $0207

    LDA $020B
    CLC
    ADC #$01
    STA $020B

    LDA $020F
    CLC
    ADC #$01
    STA $020F


ReadContRightDone:


IRQ:
   ;NOTE: IRQ code goes here

;----------------------------------------------------------------
; interrupt vectors
;----------------------------------------------------------------

   .org $fffa

   .dw NMI
   .dw Reset
   .dw IRQ


;----------------------------------------------------------------
; CHR-ROM bank
;----------------------------------------------------------------

    .incbin "tiles.chr"