Programs

This program handles an interrupt which is generated when the button on the rabbit’s head is pressed. It flashes some lights all the time, to show that the program hasn’t locked-up, and it flashes another light when the button is pressed.

ID      0x7ffffffd
TRANSITION IMMEDIATE
 
# 0: black, 1: red, 2: green, 3: yellow, 4: blue, 5: purple, 6: cyan, 7: white
 
# Set the LEDs to black
    LD R2,5
ledreset:
    DEC R2
    LD R0,0
    LD R1,0
    BSR @setanlednow
    TST R2
    BEQ @ledreset1
    BRA @ledreset
ledreset1:
 
    # Register the interrupt handler
    LD R0,0
    INPUT R0,@int_handler
 
    LD R0,1
    LD R1,255
    LD R2,0
    BSR @setanlednow
mainloop:
    LD R0,1
    LD R1,255
    LD R2,0
    BSR @setanlednow
    WAIT 10
    LD R0,4
    LD R1,255
    LD R2,0
    BSR @setanlednow
    WAIT 10
    BRA @mainloop
 
int_handler:
    PUSH R2,R1,R0
    # Set an LED
    LD R0,7
    LD R1,255
    LD R2,2
    BSR @setanlednow
    WAIT 5
    LD R0,5
    LD R1,255
    LD R2,2
    BSR @setanlednow
    PULL R2,R1,R0
    RTI
 
# Call "BSR @setanlednow" with the palette colour
# in R0, the intensity in R1, and the LED number
# in R2
setanlednow:
    PUSH R7,R6,R5,R4,R3,R2,R1,R0
    LD R7,0
    LD R6,R2
    LD R5,R1
    LD R4,R0
    PALETTE R4,R5
    LED R6,R7
    PULL R7,R6,R5,R4,R3,R2,R1,R0
    RTS