TunnelBot2

function DigandMove()
 turtle.dig()
 os.sleep( 1 )
 while turtle.detect() do
  turtle.dig()
  os.sleep( 1 )
 end
 turtle.forward()
end

for t=1,30000 do
 DigandMove()
 turtle.turnRight()
 turtle.digDown()
 for i=1,3 do
  DigandMove()
  turtle.digDown()
  if i < 3 then
   turtle.digUp()
   os.sleep( 1 )
   while turtle.detectUp() do
    turtle.digUp()
    os.sleep( 1 )
   end
  end
 end
 for i=1,9 do
  turtle.drop()
 end
 turtle.turnLeft()
 DigandMove()
 turtle.turnLeft()
 turtle.digDown()
 for i=1,3 do
  DigandMove()
  turtle.digDown()
  if i<3 then
   turtle.digUp()
   os.sleep( 1 )
   while turtle.detectUp() do
    turtle.digUp()
    os.sleep( 1 )
   end
  end
 end
 for i=1,9 do
  turtle.drop()
 end
 turtle.turnRight()
end