;Commander X16 ABI Registers Assembly Language Routines

;Zero Page System Variables - x16emu Release 34 Memory Map
ABIPTR  EQU $00   ;Pointer for ABI Functions
R0      EQU $02   ;ABI Register 0
R0L     EQU $02   ;ABI Register 0 LSB
R0H     EQU $03   ;ABI Register 0 MSB
R1      EQU $04   ;ABI Register 1
R1L     EQU $04   ;ABI Register 1 LSB
R1H     EQU $05   ;ABI Register 1 MSB
R2      EQU $06   ;ABI Register 2
R2L     EQU $06   ;ABI Register 2 LSB
R2H     EQU $07   ;ABI Register 2 MSB
R3      EQU $08   ;ABI Register 3
R3L     EQU $08   ;ABI Register 3 LSB
R3H     EQU $09   ;ABI Register 3 MSB
R4      EQU $0A   ;ABI Register 4
R4L     EQU $0A   ;ABI Register 4 LSB
R4H     EQU $0B   ;ABI Register 4 MSB
R5      EQU $0C   ;ABI Register 5
R5L     EQU $0C   ;ABI Register 5 LSB
R5H     EQU $0D   ;ABI Register 5 MSB
R6      EQU $0E   ;ABI Register 6
R6L     EQU $0E   ;ABI Register 6 LSB
R6H     EQU $0F   ;ABI Register 6 MSB
R7      EQU $10   ;ABI Register 7
R7L     EQU $10   ;ABI Register 7 LSB
R7H     EQU $11   ;ABI Register 7 MSB
R8      EQU $12   ;ABI Register 8
R8L     EQU $12   ;ABI Register 8 LSB
R8H     EQU $13   ;ABI Register 8 MSB
R9      EQU $14   ;ABI Register 9
R9L     EQU $14   ;ABI Register 9 LSB
R9H     EQU $15   ;ABI Register 9 MSB
R10     EQU $16   ;ABI Register 10
R10L    EQU $16   ;ABI Register 10 LSB
R10H    EQU $17   ;ABI Register 10 MSB
R11     EQU $18   ;ABI Register 11
R11L    EQU $18   ;ABI Register 11 LSB
R11H    EQU $19   ;ABI Register 11 MSB
R12     EQU $1A   ;ABI Register 12
R12L    EQU $1A   ;ABI Register 12 LSB
R12H    EQU $1B   ;ABI Register 12 MSB
R13     EQU $1C   ;ABI Register 13
R13L    EQU $1C   ;ABI Register 13 LSB
R13H    EQU $1D   ;ABI Register 13 MSB
R14     EQU $1E   ;ABI Register 14
R14L    EQU $1E   ;ABI Register 14 LSB
R14H    EQU $1F   ;ABI Register 14 MSB
R15     EQU $20   ;ABI Register 15
R15L    EQU $20   ;ABI Register 15 LSB
R15H    EQU $21   ;ABI Register 15 MSB

;Read ABI Registers into Array or Struct
GETABI: STX ABIPTR      ;Store Array Address
        STY ABIPTR+1    
        TAY             ;Copy Array Size into Y Register
GETABY: DEY             ;Decrement Counter
        BMI .GETABX     ;If Not Negative
        LDA R0,Y        ;Get Byte from ABI Register
        STA (ABIPTR),Y  ;And write to ABI Register
        BRA GETABY      ;and Loop
.GETABX RTS

;Return ABI Register Contents
GETABR: TAX             ;Copy Register 


;Write Array or Struct to ABI Registers 
SETABI: STX ABIPTR      ;Store Array Address
        STY ABIPTR+1    
        TAY             ;Copy Array Size into Y Register
SETABY: DEY             ;Decrement Counter
        BMI .SETABX     ;If Not Negative
        LDA (ABIPTR),Y  ;Get Byte from Array or Struct
        STA R0,Y        ;Store in ABI Register
        BRA SETABY      ;and Loop
.SETABX RTS