View difference between Paste ID: qTyHf99T and 9bMt4rgA

 print("ok")
 local origin = {0,0,0}
 local max = {72,2,144}
 local dir = 1;
 local modX = {0,1,0,-1}
 local modZ = {-1,0,1,0}
 local location = {0,0,0}
 
 function turnAround()
 right()
 right()
 end
 
 function right()
   dir = dir + 1 % 5
 end
 
 
 
 function left()
   dir = dir - 1
   if dir < 1 then
     dir = 1
   end
 end
 
 function down(dig)
   while true do
     if turtle.down() then
       break
     end
     if turtle.detectDown() then
       if dig then
         turtle.digDown()
       end
     end
     sleep(0)
   end
   location[1]=location[1]-1
 end
 
 function up(dig)
   while true do
     if turtle.up() then
       break
     end
     if dig then
       if turtle.detectUp() then
         turtle.digUp()
       end
     end
   sleep(0)
   end
   location[2] = location[2] + 1
 end
 function forward(dig)
   while true do
     if turtle.forward() then
       break
     end
     if turtle.detect() then
       if dig then
         turtle.dig()
       end
     end
     sleep(0)
   end
   print(dir);
   location[1] = location[1] + modX[dir];
   location[3] = location[3] + modZ[dir];
 end
 
 function back(dig)
   while true do
     if turtle.back() then
       break
     end
     if dig then
       turnAround()
       if turlte.detect() then
         turtle.dig()
       end
       turnAround()
     end
     sleep(0)
   end
   location[1] = location[1]+modX[dir];
   location[3] = location[3]+modZ[dir];
 end
 
 function getLocCopy()
   local copy = {}
   for i,n in ipairs(location) do
     copy[i]=n
   end
   return copy;
 end
 
 function checkInventory()
   if turtle.getItemCount(9) > 0 then
     return true
    end
    return false
 end
 
 function dropOff(x,y,z)
   local org = getLocCopy()
   if z%2 == 1 then
     left()
     forward(false)
     right()
   end
   while dir~=2 do
     left()
     sleep(0)
   end
   while location[3] ~= origin[3] do
     forward(false)
     sleep(0)
   end
   if location[1] ~= origin[1] then
     local left = false
     if location[1] <0 then
       left()
       left = true
     elseif location[1]>0 then
       right()
     end
     while location[1] ~= origin[1] do
       forward(false)
       sleep(0)
     end
 
     if left then
      right()
     else
       left()
     end
 
   end
   forward(false)
   forward(false)
   dropAll()
   turnAround()
   forward(false)
   forward(false)
 
   if left then
     left()
   else
     right()
   end
   while location[1] ~= org[1] do
       forward(false)
       sleep(0)
   end
 
   if left then
     right()
   else
     left()
   end
   if org[3] % 2 == 1 then
     right()
 	forward(false)
 	left()
   end
   while location[3]~=org[3] do
     forward(false)
 	sleep(0)
   end
   if org[3]%2==1 then
     left()
 	forward(true)
 	right()
 
   end
 
 end
 
 function dropAll()
   for i=1,9,1 do
     turtle.select(i)
     if turtle.getItemCount(i) >0 then
       turtle.drop(turtle.getItemCount(i));
     end
   end
 
 end
 
 local input = ""
 while input ~= "start" do
   input = io.read()
   sleep(0)
 end
 
 local location = {0,0,0}
 
   for x=0,max[1],1 do
     for z=0,max[3],1 do
       for y=1,max[2]-1,1 do
 
-        up(true);
+        while turtle.detectUp() do
 		  turtle.digUp()
 		  sleep(0)
 		end
         checkInventory()
         down(false);
 		print(tostring(x).."/"..tostring(y).."/"..tostring(z))
-	    dropOff()
+
       forward(true);
       if checkInventory() then
 	    dropOff(x,y,z)
       end
     end
     left()
     forward(true)
     left()
     back(true)
   end