diff --git a/compacting-storage.lua b/compacting-storage.lua
index 5bedc20..7477cae 100644
--- a/compacting-storage.lua
+++ b/compacting-storage.lua
@@ -7,7 +7,8 @@
 -- constants
 
 local INVENTORY = ""
-local SLEEP_TIME = 5
+local SLEEP_TIME = 30
+local AMOUNT_PER = 63 -- the amount of item change per request
 local ITEM_TYPES = { "iron", "copper", "zinc", "gold", "electrum" }
 local PRIORITY = { "ingot", "block", "nugget" }
 
@@ -17,8 +18,16 @@ end
 
 -- TODO map targets to specific relays
 local target = {}
+target.iron = peripheral.wrap""
+target.copper = peripheral.wrap""
+target.zinc = peripheral.wrap""
+target.gold = peripheral.wrap""
+target.electrum = peripheral.wrap""
+
+-- Levels
+local limits = {}
 for _, type in ipairs(ITEM_TYPES) do
-    target[type] = {
+    limits[type] = {
         "nugget" = { stacks(4), stacks(8) },
         "ingot" = { stacks(4), stacks(8) },
         "block" = { stacks(4), stacks(1000) }
@@ -51,9 +60,9 @@ end
 
 -- basic actions
 function request (item_type, conversion_type)
-    target[item_type].setOutput(convert.conversion_type, true)
+    target[item_type].setOutput(convert[conversion_type], true)
     os.sleep(0.05)
-    target[item_type].setOutput(convert.conversion_type, false)
+    target[item_type].setOutput(convert[conversion_type], false)
 end
 
 function request_multiple (item_type, conversion_type, count)
@@ -68,8 +77,6 @@ function request_multiple (item_type, conversion_type, count)
 end
 
 -- fundamental actions
--- assumptions: a drain or fill of 1 will increase or decrease the amount of
--- that item by 63
 function drain (type, form, amount)
     local conversion = nil
     if form == "nugget" then
@@ -95,14 +102,12 @@ function fill (type, form, amount)
 end
 
 -- making the decision what to do
--- assumptions: a drain or fill of 1 will increase or decrease the amount of
--- that item by 63
 function should_drain (type, counts)
     local drain_form, amount = nil, 0
     for _, form in ipairs(PRIORITY) do
         local diff = counts[form] - target[type][form][2]
         if diff > 0 then
-            amount = math.ceil(diff / 63)
+            amount = math.ceil(diff / AMOUNT_PER)
             drain_form = form
             return drain_form, amount
         end
@@ -115,7 +120,7 @@ function should_fill (type, counts)
         local diff = target[type][form][1] - counts[form]
         if diff > 0 then
             if fill_dest == nil then
-                amount = math.ceil(diff / 63)
+                amount = math.ceil(diff / AMOUNT_PER)
                 fill_dest = form
             end
         else