millfork/include/c64_cia.mfk

// Hardware addresses for C64

#if not(CBM_64)
#warn c64_cia module should be only used on C64-compatible targets
#endif

//   CIA1
volatile byte cia1_pra       @$DC00
volatile byte cia1_prb       @$DC01
byte cia1_ddra      @$DC02
byte cia1_ddrb      @$DC03
volatile byte cia2_pra       @$DD00
volatile byte cia2_prb       @$DD01
byte cia2_ddra      @$DD02
byte cia2_ddrb      @$DD03

macro asm void cia_disable_irq() {
    ? LDA #$7f
    ! LDA $dc0d
    ! LDA $dd0d
    ! LDA $dc0d
    ! LDA $dd0d
}


macro void vic_bank_0000() {
    cia2_ddra = 3
    cia2_pra = 3
}

macro void vic_bank_4000() {
    cia2_ddra = 3
    cia2_pra = 2
}

macro void vic_bank_8000() {
    cia2_ddra = 3
    cia2_pra = 1
}

macro void vic_bank_C000() {
    cia2_ddra = 3
    cia2_pra = 0
}