Turtle Quarry Bot 20x20

turtle.select(1)
turtle.refuel()
turtle.select(2)
turtle.refuel()
turtle.select(1)

Depth = 2

-- The function selecting the length of the quarry.
function forward()
    local length = 20

    for i = 1, length, 1 do
        turtle.dig()
        turtle.forward()
    end
end

-- The function calling the turtle back to the chest/unloading area.
function home()
    local blocks = 20
    turtle.turnLeft()
    for i = 1, blocks, 1 do
        turtle.forward()
    end
    for i = 1, Depth, 1 do
        turtle.up()
    end
    turtle.turnLeft()
    turtle.forward()
    local inventory = 16
    local x = 1
    for i = 1, inventory, 1 do
        turtle.select(x)
        turtle.dropDown()
        x = x + 1
    end
end

-- The function that loops the turtle's digging.
function turn()
    local size = 10
    for i = 1, size do
        turtle.turnRight()
        turtle.dig()
        turtle.forward()
        turtle.turnRight()
        forward()
        turtle.turnLeft()
        turtle.dig()
        turtle.forward()
        turtle.turnLeft()
        forward()
    end
end

-- The function returning the turtle to it's diggingpoint.
function back()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.forward()
    for i = 1, Depth, 1 do
        turtle.digDown()
        turtle.down()
    end
end

-- The loop that keeps the program going.
while(true)do
    turn()
    home()
    Depth = Depth + 1
    back()
end

-- pastebin get wqjagUfU mine