JP   Start
    NOP
    NOP
    NOP

    RET
    LD   R0, (R1)
    LD   (R0), R1
    LD   R0, R1
    LD   R0, 1
    LD   (R0 + 1), R1
    ;LD   (R0), (R1)
    LD   D1, R0, 1
    LD   D1, R0, R1

    JP   Start
    NOP
    NOP
    NOP

    VAR  DeviceConsole 1
    VAR  ConsoleReadChar 0
    VAR  ConsoleWriteChar 0

    VAR  DeviceKeyboard 2

    VAR  DeviceScreen 3
    VAR  ScreenGetWidth 0
    VAR  ScreenGetHeight 1
    VAR  ScreenSetAddr 0
    VAR  ScreenWrite 1

Start:
    LD   R0, Hello
    LD   R1, 12
    CALL WriteStr

    ;LD   R0, 64
    ;LD   R1, 8
    ;OUT  (R1), R0
    ;LD   R1, 0
    ;LD   R2, 10
    ;OUT  (R1), R0
;Loop:
    ;INC  R0
    ;DEC  R2
    ;JNZ  R2, Loop
    HALT

WriteStr:
    ; R0 - string address
    ; R1 - string length
    PUSH R2
    PUSH R3
    PUSH R4
    LD   R3, ConsoleWriteChar
WriteStrLoop:
    LD   D1, R2, (R0)
    OUT  D1, (R3), R2
    INC  R0
    DEC  R1
    JNZ  R1, WriteStrLoop
    POP  R4
    POP  R3
    POP  R2
    RET

ClearScreen:
    PUSH R0
    PUSH R1
    PUSH R2
    PUSH R3
    LD   R0, ScreenSetAddr
    LD   R1, 0
    OUT  (R0), R1
    LD   R0, ScreenGetWidth
    IN   R1, (R0)
    LD   R0, ScreenGetHeight
    IN   R2, (R0)
    MUL  R2, R1
    LD   R0, ScreenWrite
    LD   R1, 120
ClearScreenLoop:
    OUT  (R0), R1
    DEC  R2
    JNZ  R2, ClearScreenLoop
    POP  R3
    POP  R2
    POP  R1
    POP  R0
    RET

Hello:
    DB   'Hello friend'

KeyInterrupt:
    ; Echo key
    PUSH R3
    PUSH R2
    PUSH R4
    LD   R3, ConsoleReadChar
    IN   R2, (R3)
    LD   R3, ConsoleWriteChar
    OUT  (R3), R2
    POP  R4
    POP  R2
    POP  R3
    RET

Test:
    LD   R0, (R1 + 1)
    LD   (R1 + 12), R2