morse_demo.8o

# CHIP-8 Morse Code Demo
# Copyright 2015 Matthew Mikolay
# See github.com/mattmikolay/chip-8 or mattmik.com for more info.

:alias x v0                     # x coordinate of current character
:alias y v1                     # y coordinate of current character
:alias delay_reg v2             # Register used for general timing
:alias sound_reg v3             # Register used for beeps and boops

:const MESSAGE_X 11             # x coordinate of message top left
:const MESSAGE_Y 14             # y coordinate of message top left

:const DASH_LENGTH 15           # Duration of Morse code dash
:const DOT_LENGTH 5             # Duration of Morse code dot
:const DASH_DOT_LENGTH 20       # Duration of Morse code dash followed by dot
:const DOT_DOT_LENGTH 10        # Duration of Morse code dot followed by dot

# Duration between the printing of individual letters.
# This value should be 2 * DOT_LENGTH, as it always follows an
# extra duration of DOT_LENGTH.
:const LETTER_SEP_LENGTH 10

# Duration between the printing of complete words.
# This value should be 6 * DOT_LENGTH, as it always follows an
# extra duration of DOT_LENGTH.
:const WORD_SEP_LENGTH 30       # Duration of 

# Duration of delay before erasing entire "COSMAC VIP" message
:const PAUSE_LENGTH 120

: main

    clear

    i := sprite_border

    # Draw borders at top and bottom of screen
    x := 0
    loop

        y := 0
        sprite x y 13

        y := 20
        sprite x y 12

        x += 8

        if x != 64 then

    again

    y := MESSAGE_Y

: type_letters

    x := MESSAGE_X

    draw_c
    play_dash
    play_dot
    play_dash
    play_dot
    draw_c
    end_letter
    x += 4

    draw_o
    play_dash
    play_dash
    play_dash
    draw_o
    end_letter
    x += 4

    draw_s
    play_dot
    play_dot
    play_dot
    draw_s
    end_letter
    x += 4

    draw_m
    play_dash
    play_dash
    draw_m
    end_letter
    x += 6

    draw_a
    play_dot
    play_dash
    draw_a
    end_letter
    x += 4

    draw_c
    play_dash
    play_dot
    play_dash
    play_dot
    draw_c
    end_word
    x += 9

    draw_v
    play_dot
    play_dot
    play_dot
    play_dash
    draw_v
    end_letter
    x += 4

    draw_i
    play_dot
    play_dot
    draw_i
    end_letter
    x += 4

    draw_p
    play_dot
    play_dash
    play_dash
    play_dot
    draw_p
    end_word

    # Draw the entire message
    draw_all

    # Wait a bit before erasing the text
    delay_reg := PAUSE_LENGTH
    delay := delay_reg
    loop
        delay_reg := delay
        while delay_reg != 0x00
    again

    # Erase the entire message
    draw_all

    jump type_letters

: play_dash
    sound_reg := DASH_LENGTH
    delay_reg := DASH_DOT_LENGTH
    buzzer := sound_reg
    delay := delay_reg
    loop
        delay_reg := delay
        while delay_reg != 0x00
    again
    return

: play_dot
    sound_reg := DOT_LENGTH
    delay_reg := DOT_DOT_LENGTH
    buzzer := sound_reg
    delay := delay_reg
    loop
        delay_reg := delay
        while delay_reg != 0x00
    again
    return

: end_letter
    delay_reg := LETTER_SEP_LENGTH
    delay := delay_reg
    loop
        delay_reg := delay
        while delay_reg != 0x00
    again
    return

: end_word
    delay_reg := WORD_SEP_LENGTH
    delay := delay_reg
    loop
        delay_reg := delay
        while delay_reg != 0x00
    again
    return

: draw_c
    i := sprite_c
    sprite x y 5
    return

: draw_o
    i := sprite_o
    sprite x y 5
    return

: draw_s
    i := sprite_s
    sprite x y 5
    return

: draw_m
    i := sprite_m
    sprite x y 5
    return

: draw_a
    i := sprite_a
    sprite x y 5
    return

: draw_v
    i := sprite_v
    sprite x y 5
    return

: draw_i
    i := sprite_i
    sprite x y 5
    return

: draw_p
    i := sprite_p
    sprite x y 5
    return

: draw_all

    x := MESSAGE_X

    draw_c
    x += 4

    draw_o
    x += 4

    draw_s
    x += 4

    draw_m
    x += 6

    draw_a
    x += 4

    draw_c
    x += 9

    draw_v
    x += 4

    draw_i
    x += 4

    draw_p
    return

: sprite_c
    0xE0
    0xA0
    0x80
    0xA0
    0xE0

: sprite_o
    0xE0
    0xA0
    0xA0
    0xA0
    0xE0

: sprite_s
    0xE0
    0x80
    0xE0
    0x20
    0xE0

: sprite_m
    0xF8
    0xA8
    0xA8
    0xA8
    0xA8

: sprite_a
    0xE0
    0xA0
    0xE0
    0xA0
    0xA0

: sprite_v
    0xA0
    0xA0
    0xA0
    0xA0
    0x40

: sprite_i
    0xE0
    0x40
    0x40
    0x40
    0xE0

: sprite_p
    0xE0
    0xA0
    0xE0
    0x80
    0x80

: sprite_border
    0xFF
    0x00
    0xFF
    0x00
    0xFF
    0x00
    0xFF
    0x00
    0xFF
    0x00
    0xFF
    0x00
    0xFF