millfork/include/vcs_hardware.mfk

#if not(ATARI_2600)
#warn vcs_hardware module should be only used on Atari 2600-compatible targets
#endif

volatile byte VSYNC @$00
volatile byte VBLANK @$01
volatile byte WSYNC @$02
volatile byte RSYNC @$03
volatile byte NUSIZ0 @$04
volatile byte NUSIZ1 @$05
volatile byte COLUP0 @$06
volatile byte COLUP1 @$07
volatile byte COLUPF @$08
volatile byte COLUBK @$09
volatile byte CTRLPF @$0A
volatile byte REFP0 @$0B
volatile byte REFP1 @$0C
volatile byte PF0 @$0D
volatile byte PF1 @$0E
volatile byte PF2 @$0F
volatile byte RESP0 @$10
volatile byte RESP1 @$11
volatile byte RESM0 @$12
volatile byte RESM1 @$13
volatile byte RESBL @$14
volatile byte AUDC0 @$15
volatile byte AUDC1 @$16
volatile byte AUDF0 @$17
volatile byte AUDF1 @$18
volatile byte AUDV0 @$19
volatile byte AUDV1 @$1A
volatile byte GRP0 @$1B
volatile byte GRP1 @$1C
volatile byte ENAM0 @$1D
volatile byte ENAM1 @$1E
volatile byte ENABL @$1F
volatile byte HMP0 @$20
volatile byte HMP1 @$21
volatile byte HMM0 @$22
volatile byte HMM1 @$23
volatile byte HMBL @$24
volatile byte VDELP0 @$25
volatile byte VDELP1 @$26
volatile byte VDELBL @$27
volatile byte RESMP0 @$28
volatile byte RESMP1 @$29
volatile byte HMOVE @$2A
volatile byte HMCLR @$2B
volatile byte CXCLR @$2C
volatile byte CXM0P @$30
volatile byte CXM1P @$31
volatile byte CXP0FB @$32
volatile byte CXP1FB @$33
volatile byte CXM0FB @$34
volatile byte CXM1FB @$35
volatile byte CXBLPF @$36
volatile byte CXPPMM @$37
volatile byte INPT0 @$38
volatile byte INPT1 @$39
volatile byte INPT2 @$3A
volatile byte INPT3 @$3B
volatile byte INPT4 @$3C
volatile byte INPT5 @$3D
volatile byte SWCHA @$0280
volatile byte SWACNT @$0281
volatile byte SWCHB @$0282
volatile byte SWBCNT @$0283
volatile byte INTIM @$0284
volatile byte INSTAT @$0285
volatile byte TIM1T @$0294
volatile byte TIM8T @$0295
volatile byte TIM64T @$0296
volatile byte T1024T @$0297


macro asm void wsync() {
    STA WSYNC
}

macro asm void start_frame() {
    ? LDA #0
    ! STA VBLANK
    ? LDA #2
    ! STA VSYNC
    ! STA WSYNC
    ! STA WSYNC
    ! STA WSYNC
    ! LDA #0
    ! STA VSYNC
    ? LDX #37
    start_frame_loop:
    ! STA WSYNC
    ? DEX
    BNE start_frame_loop
}
macro asm void end_frame() {
    ? LDA #%01000010
    ! STA VBLANK
    ? LDX #30
    end_frame_loop:
    ! STA WSYNC
    ? DEX
    BNE end_frame_loop
}

asm void reset_routine() @$FFF4 {
    LDX #$FF
    TXS
    JMP main
}

const array __vectors @$FFFA = @word [
    reset_routine.addr,
    reset_routine.addr,
    reset_routine.addr
]