random_number_test.8o

# Random Number Test
# Copyright 2015 Matthew Mikolay
# See github.com/mattmikolay/chip-8 or mattmik.com for more info.

# Note: Don't use v0, v1, or v2, as they are needed for printing digits
:alias value v3                 # Register used to store random value
:alias x v4                     # x coordinate of current digit
:alias y v5                     # y coordinate of current digit

: main

    y := 0

    loop

        clear

        # Generate a random value between 0 and 255 inclusive
        value := random 0b11111111

        # Store BCD of random value in program memory
        i := program_end
        bcd value
        load v2

        x := 0

        # Print hundreds digit
        i := hex v0
        sprite x y 0x05

        x += 5

        # Print tens digit
        i := hex v1
        sprite x y 0x05

        x += 5

        # Print ones digit
        i := hex v2
        sprite x y 0x05

        # Wait for a keypress
        value := key

    again

: program_end