TestOS.sb

# Highlighted for brainfuck, but /not/ brainfuck

{  # The INTERVAL interrupt- currently, it just records how often it's been called in cell 3
    =>>  # Go to the first cell then go right by 2 (to cell #3)
    +  # Increment cell 3
    %  # Return to whatever was going on previously
}

+ {  # ZERO DIVISION INTERRUPT: Called when a number is divided by 0
    # Nothing to do here (we don't even use div`, so you never divide by 0)
}

+2 {  # The KEYBOARD interrupt- Triggered when a key is pressed
    [>]  # Find a cell we can interfere with
    +753664*  # Go to the terminal register
    [>]  # Go to the fist cell the terminal has that isn't open
    ?    # Query hardware 0 (KEYBOAaD) for what key was most recently pressed
    +2560  # Colorize the cell
    % # Return to whatever was going on before (jump back to the old cell)
}

+16{  # Main method- called when the kernel loads
    +753664*  # Go to the proper register

    +2560  # Colorize
    +107>  # Print "k"
    +2560
    +101>  # Print "e"
    +2560
    +114>  # Print "r"
    +2560
    +110>  # Print "n"
    +2560
    +101>  # Print "e"
    +2560
    +108>  # Print "l"
    +2560
    +32>   # Print <space>
    +2560
    +98>   # Print "b"
    +2560
    +111>  # Print "o"
    +2560
    +111>  # Print "o"
    +2560
    +116>  # Print "t"
    +2560
    +105>  # Print "i"
    +2560
    +110>  # Print "n"
    +2560
    +103>  # Print "g"
    (+>)66    # Go to the next line (width-80 display)
    +[]    # Hang forever without terminating
}:  # Execute the main method