wool

function drop()
    slot = 1
    turtle.select(slot)
    for x=1, 12 do
        if turtle.getItemCount(slot) > 0 then
            turtle.select(slot)
            turtle.dropDown()
        end
        slot = slot + 1
    end
    slot = 1
end

function place()
    turtle.select(shear)
    while turtle.getItemCount(shear) == 0 do
        shear = shear + 1
        if shear == 17 then
            redstone.setOutput("top", false)
            error()
        end
    end
    turtle.place()
end

function wool()
    while true do
        turtle.turnRight()
        place()
        drop()
        sleep(60)
    end
end

shear = 13
redstone.setOutput("top", true)

repeat
        result, err = pcall(wool)
        if not result then
                print("Horrible nasty stuff happened...")
                print(err)
                print("Whatever happend... The killing needs to resume!")
        end
        os.sleep(60)
until false