local characters = {
    "`", "1", "2", "3", "4", "5", "6", "7", "8", "9", "0", "-", "=",
    "~", "!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "_", "+"
}
local monitor = peripherals.find("monitor")

function getCharacter()
    return characters[math.random(1, #characters)]
end

function render()
    for x = 1, 51 do
        for y = 1, 19 do
            monitor.setTextColor(colors.green)
            monitor.setCursorPos(x, y)
            monitor.write(getCharacter())
        end
    end
end