diff --git a/basic_machines/chest.lua b/basic_machines/chest.lua
index 6ec5d45..3d60697 100644
--- a/basic_machines/chest.lua
+++ b/basic_machines/chest.lua
@@ -23,27 +23,27 @@ local InventoryState = {}
 local function store_action(pos, player, action, stack)
 	local meta = minetest.get_meta(pos)
 	local name = player and player:get_player_name() or ""
-	local number = meta:get_string("number")
+	local number = meta:get_string("node_number")
 	local item = stack:get_name().." "..stack:get_count()
 	PlayerActions[number] = {name, action, item}
 end	
 
 local function send_off_command(pos)
 	local meta = minetest.get_meta(pos)
-	local dest_num = meta:get_string("dest_num")
-	local own_num = meta:get_string("number")
-	local owner = meta:get_string("owner")
-	techage.send_multi(dest_num, owner, nil, "off", own_num)
+	local numbers = meta:get_string("numbers") or ""
+	if numbers ~= "" then
+		local own_num = meta:get_string("node_number")
+		techage.send_multi(numbers, "off", own_num)
+	end
 end
 
 
 local function send_command(pos)
 	local meta = minetest.get_meta(pos)
-	local dest_num = meta:get_string("dest_num")
-	if dest_num ~= "" then
-		local own_num = meta:get_string("number")
-		local owner = meta:get_string("owner")
-		techage.send_multi(dest_num, owner, nil, "on", own_num)
+	local numbers = meta:get_string("numbers") or ""
+	if numbers ~= "" then
+		local own_num = meta:get_string("node_number")
+		techage.send_multi(numbers, "on", own_num)
 		minetest.after(1, send_off_command, pos)
 	end
 end
@@ -110,12 +110,16 @@ minetest.register_node("techage:chest_ta2", {
 	after_place_node = function(pos, placer)
 		local meta = minetest.get_meta(pos)
 		local number = techage.add_node(pos, "techage:chest_ta2")
-		meta:set_string("number", number)
+		meta:set_string("node_number", number)
 		meta:set_string("owner", placer:get_player_name())
 		meta:set_string("formspec", formspec2())
 		meta:set_string("infotext", S("TA2 Protected Chest").." "..number)
 	end,
 
+	techage_set_numbers = function(pos, numbers, player_name)
+		return techage.logic.set_numbers(pos, numbers, player_name, S("TA2 Protected Chest"))
+	end,
+	
 	can_dig = can_dig,
 	after_dig_node = after_dig_node,
 	allow_metadata_inventory_put = allow_metadata_inventory_put,
@@ -159,12 +163,16 @@ minetest.register_node("techage:chest_ta3", {
 	after_place_node = function(pos, placer)
 		local meta = minetest.get_meta(pos)
 		local number = techage.add_node(pos, "techage:chest_ta3")
-		meta:set_string("number", number)
+		meta:set_string("node_number", number)
 		meta:set_string("owner", placer:get_player_name())
 		meta:set_string("formspec", formspec3())
 		meta:set_string("infotext", S("TA3 Protected Chest").." "..number)
 	end,
 
+	techage_set_numbers = function(pos, numbers, player_name)
+		return techage.logic.set_numbers(pos, numbers, player_name, S("TA3 Protected Chest"))
+	end,
+	
 	can_dig = can_dig,
 	after_dig_node = after_dig_node,
 	allow_metadata_inventory_put = allow_metadata_inventory_put,
@@ -208,12 +216,16 @@ minetest.register_node("techage:chest_ta4", {
 	after_place_node = function(pos, placer)
 		local meta = minetest.get_meta(pos)
 		local number = techage.add_node(pos, "techage:chest_ta4")
-		meta:set_string("number", number)
+		meta:set_string("node_number", number)
 		meta:set_string("owner", placer:get_player_name())
 		meta:set_string("formspec", formspec4())
 		meta:set_string("infotext", S("TA4 Protected Chest").." "..number)
 	end,
 
+	techage_set_numbers = function(pos, numbers, player_name)
+		return techage.logic.set_numbers(pos, numbers, player_name, S("TA4 Protected Chest"))
+	end,
+	
 	can_dig = can_dig,
 	after_dig_node = after_dig_node,
 	allow_metadata_inventory_put = allow_metadata_inventory_put,
@@ -249,16 +261,8 @@ techage.register_node({"techage:chest_ta2", "techage:chest_ta3", "techage:chest_
 			return techage.get_inv_state(inv, "main")
 		elseif topic == "player_action" then
 			local meta = minetest.get_meta(pos)
-			local number = meta:get_string("number")
+			local number = meta:get_string("node_number")
 			return PlayerActions[number]
-		elseif topic == "set_numbers" then
-			if techage.check_numbers(payload) then
-				local meta = minetest.get_meta(pos)
-				meta:set_string("dest_num", payload)
-				local number = meta:get_string("number")
-				meta:set_string("infotext", S("TA Protected Chest").." "..number.." "..S("connected with").." "..payload)
-				return true
-			end
 		else
 			return "unsupported"
 		end
diff --git a/basis/command.lua b/basis/command.lua
index 8ad5c34..b8f0e06 100644
--- a/basis/command.lua
+++ b/basis/command.lua
@@ -83,10 +83,11 @@ end
 local function not_protected(pos, placer_name, clicker_name)
 	local meta = minetest.get_meta(pos)
 	if meta then
-		local cached_name = meta:get_string("techage_cached_name")
-		if placer_name and (placer_name == cached_name or not minetest.is_protected(pos, placer_name)) then
-			meta:set_string("techage_cached_name", placer_name)
-			if clicker_name == nil or not minetest.is_protected(pos, clicker_name) then
+		if placer_name and not minetest.is_protected(pos, placer_name) then
+			if clicker_name == nil or placer_name == clicker_name then
+				return true
+			end
+			if not minetest.is_protected(pos, clicker_name) then
 				return true
 			end
 		end
@@ -157,20 +158,6 @@ end
 -- API helper functions
 -------------------------------------------------------------------
 	
--- Check the given list of numbers.
--- Returns true if number(s) is/are valid and point to real nodes.
-function techage.check_numbers(numbers)
-	if numbers then
-		for _,num in ipairs(string_split(numbers, " ")) do
-			if Number2Pos[num] == nil then
-				return false
-			end
-		end
-		return true
-	end
-	return false
-end	
-
 -- Function returns { pos, name } for the node on the given position number.
 function techage.get_node_info(dest_num)
 	if Number2Pos[dest_num] then
@@ -297,6 +284,21 @@ function techage.not_protected(number, placer_name, clicker_name)
 	return false
 end
 
+-- Check the given list of numbers.
+-- Returns true if number(s) is/are valid, point to real nodes and
+-- and the nodes are not protected for the given player_name.
+function techage.check_numbers(numbers, placer_name)
+	if numbers then
+		for _,num in ipairs(string_split(numbers, " ")) do
+			if not techage.not_protected(num, placer_name, nil) then
+				return false
+			end
+		end
+		return true
+	end
+	return false
+end	
+
 function techage.send_multi(numbers, topic, payload)
 	for _,num in ipairs(string_split(numbers, " ")) do
 		if Number2Pos[num] and Number2Pos[num].name then
diff --git a/doc/ta3_doc.lua b/doc/ta3_doc.lua
index e977318..38b2e20 100644
--- a/doc/ta3_doc.lua
+++ b/doc/ta3_doc.lua
@@ -109,5 +109,5 @@ techage.register_category_page("ta3l",
 	S("TA3: Logic"),
 	S("Collection of TA3 logic blocks to control your machines."),
 	"techage:terminal2", 
-	{"terminal"}
+	{"terminal", "button", "detector", "repeater", "programmer"}
 )
diff --git a/init.lua b/init.lua
index 24e5d85..54359bb 100644
--- a/init.lua
+++ b/init.lua
@@ -149,7 +149,12 @@ else
 	end
 	
 	-- Logic
+	dofile(MP.."/logic/lib.lua")
 	dofile(MP.."/logic/terminal.lua")
+	dofile(MP.."/logic/button.lua")
+	dofile(MP.."/logic/detector.lua")
+	dofile(MP.."/logic/repeater.lua")
+	dofile(MP.."/logic/programmer.lua")
 
 	-- Test
 	dofile(MP.."/recipe_checker.lua")
diff --git a/logic/button.lua b/logic/button.lua
new file mode 100644
index 0000000..e4d5907
--- /dev/null
+++ b/logic/button.lua
@@ -0,0 +1,201 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2017-2019 Joachim Stolberg
+
+	GPL v3
+	See LICENSE.txt for more information
+
+	Logic button
+	
+]]--
+
+-- for lazy programmers
+local M = minetest.get_meta
+local S = techage.S
+
+local logic = techage.logic
+
+local function switch_on(pos)
+	local cycle_time = M(pos):get_int("cycle_time")
+	logic.swap_node(pos, "techage:button_on")
+	logic.send_on(pos, M(pos), cycle_time)
+	minetest.sound_play("techage_button", {
+			pos = pos,
+			gain = 0.5,
+			max_hear_distance = 5,
+		})
+end
+
+local function switch_off(pos)
+	logic.swap_node(pos, "techage:button_off")
+	logic.send_off(pos, M(pos))
+end
+
+local function formspec(meta)
+	local numbers = meta:get_string("numbers") or ""
+	local idx = meta:get_int("cycle_idx") or 0
+	if idx == 0 then idx = 1 end
+	return "size[7.5,6]"..
+		"dropdown[0.2,0;3;type;switch,button 2s,button 4s,button 8s,button 16s,button 32s;"..idx.."]".. 
+		"field[0.5,2;7,1;numbers;"..S("Insert destination node number(s)")..";"..numbers.."]" ..
+		"checkbox[1,3;public;public;false]"..
+		"button_exit[2,4;3,1;exit;"..S("Save").."]"
+end
+
+minetest.register_node("techage:button_off", {
+	description = S("TA3 Button/Switch"),
+	tiles = {
+		-- up, down, right, left, back, front
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_button.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_button.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_button_off.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = M(pos)
+		logic.after_place_node(pos, placer, "techage:button_off", S("TA3 Button/Switch"))
+		logic.infotext(meta, S("TA3 Button/Switch"))
+		meta:set_string("formspec", formspec(meta))
+		meta:set_string("public", "false")
+		meta:set_int("cycle_time", 0)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		if minetest.is_protected(pos, player:get_player_name()) then
+			return
+		end
+		print(dump(fields))
+		local meta = M(pos)
+		if not techage.check_numbers(fields.numbers, player:get_player_name()) then
+			return
+		end
+		
+		meta:set_string("numbers", fields.numbers)
+		if fields.public then
+			meta:set_string("public", fields.public)
+		end
+		local cycle_time = nil
+		if fields.type == "switch" then
+			meta:set_int("cycle_idx", 1)
+			cycle_time = 0
+		elseif fields.type == "button 2s" then
+			meta:set_int("cycle_idx", 2)
+			cycle_time = 2
+		elseif fields.type == "button 4s" then
+			meta:set_int("cycle_idx", 3)
+			cycle_time = 4
+		elseif fields.type == "button 8s" then
+			meta:set_int("cycle_idx", 4)
+			cycle_time = 8
+		elseif fields.type == "button 16s" then
+			meta:set_int("cycle_idx", 5)
+			cycle_time = 16
+		elseif fields.type == "button 32s" then
+			meta:set_int("cycle_idx", 6)
+			cycle_time = 32
+		end
+		if cycle_time ~= nil then
+			meta:set_int("cycle_time", cycle_time)
+		end
+		logic.infotext(meta, S("TA3 Button/Switch"))
+		if fields.exit then
+			meta:set_string("formspec", nil)
+		else
+			meta:set_string("formspec", formspec(meta))
+		end
+	end,
+	
+	on_rightclick = function(pos, node, clicker)
+		local meta = M(pos)
+		local numbers = meta:get_string("numbers")
+		if numbers ~= "" and numbers ~= nil then
+			if meta:get_string("public") == "true" or 
+					clicker:get_player_name() == meta:get_string("owner") then
+				switch_on(pos)
+			end
+		end
+	end,
+
+	techage_set_numbers = function(pos, numbers, player_name)
+		local meta = M(pos)
+		local res = logic.set_numbers(pos, numbers, player_name, S("TA3 Button/Switch"))
+		meta:set_string("formspec", formspec(meta))
+		return res
+	end,
+	
+	after_dig_node = function(pos, oldnode, oldmetadata, digger)
+		techage.remove_node(pos)
+	end,
+	
+	on_rotate = screwdriver.disallow,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+minetest.register_node("techage:button_on", {
+	description = ("TA3 Button/Switch"),
+	tiles = {
+		-- up, down, right, left, back, front
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_button.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_button.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_button_on.png",
+	},
+
+	on_rightclick = function(pos, node, clicker)
+		local meta = M(pos)
+		local numbers = meta:get_string("numbers")
+		if numbers ~= "" and numbers ~= nil then
+			if meta:get_string("public") == "true" or 
+					clicker:get_player_name() == meta:get_string("owner") then
+				switch_off(pos)
+			end
+		end
+	end,
+
+	on_timer = switch_off,
+	on_rotate = screwdriver.disallow,
+
+	techage_set_numbers = function(pos, numbers, player_name)
+		local meta = M(pos)
+		local res = logic.set_numbers(pos, numbers, player_name, S("TA3 Button/Switch"))
+		meta:set_string("formspec", formspec(meta))
+		return res
+	end,
+	
+	after_dig_node = function(pos, oldnode, oldmetadata, digger)
+		techage.remove_node(pos)
+	end,
+	
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+	drop = "techage:button_off",
+})
+
+minetest.register_craft({
+	output = "techage:button_off",
+	recipe = {
+		{"", "group:wood", ""},
+		{"default:glass", "techage:vacuum_tube", ""},
+		{"", "group:wood", ""},
+	},
+})
+
+techage.register_entry_page("ta3l", "button",
+	S("TA3 Button/Switch"), 
+	S("The Button/Switch is used to send on/off commands to machines/nodes.@n"..
+		"It can be configured as switch or as button with configurable cycle time from 2 to 32s)"),
+	"techage:button_on")
diff --git a/logic/detector.lua b/logic/detector.lua
new file mode 100644
index 0000000..cfd60c1
--- /dev/null
+++ b/logic/detector.lua
@@ -0,0 +1,154 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2017-2019 Joachim Stolberg
+
+	GPL v3
+	See LICENSE.txt for more information
+
+	Item detector
+	
+]]--
+
+-- for lazy programmers
+local M = minetest.get_meta
+local S = techage.S
+
+local logic = techage.logic
+local BLOCKING_TIME = 8 -- seconds
+
+local function switch_on(pos)
+	local mem = tubelib2.get_mem(pos)
+	local t = minetest.get_gametime()
+	if t > (mem.time or 0) then
+		logic.swap_node(pos, "techage:detector_on")
+		logic.send_on(pos, M(pos), 1)
+		mem.time = t + BLOCKING_TIME
+	end
+end
+
+local function switch_off(pos)
+	logic.swap_node(pos, "techage:detector_off")
+	logic.send_off(pos, M(pos))
+end
+
+local function formspec(meta)
+	local numbers = meta:get_string("numbers") or ""
+	return "size[7.5,3]"..
+		"field[0.5,1;7,1;numbers;"..S("Insert destination node number(s)")..";"..numbers.."]" ..
+		"button_exit[2,2;3,1;exit;"..S("Save").."]"
+end
+
+minetest.register_node("techage:detector_off", {
+	description = S("TA3 Detector"),
+	tiles = {
+		-- up, down, right, left, back, front
+		"techage_filling_ta3.png^techage_frame_ta3_top.png^techage_appl_arrow.png",
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_outp.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_inp.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_detector.png^[transformFX",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_detector.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = M(pos)
+		logic.after_place_node(pos, placer, "techage:detector_off", S("TA3 Detector"))
+		logic.infotext(meta, S("TA3 Detector"))
+		meta:set_string("formspec", formspec(meta))
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		local meta = minetest.get_meta(pos)
+		if techage.check_numbers(fields.numbers, player:get_player_name()) then
+			meta:set_string("numbers", fields.numbers)
+			logic.infotext(M(pos), S("TA3 Detector"))
+			meta:set_string("formspec", formspec(M(pos)))
+		end
+	end,
+	
+	techage_set_numbers = function(pos, numbers, player_name)
+		local meta = M(pos)
+		local res = logic.set_numbers(pos, numbers, player_name, S("TA3 Detector"))
+		meta:set_string("formspec", formspec(meta))
+		return res
+	end,
+	
+	after_dig_node = function(pos, oldnode, oldmetadata, digger)
+		techage.remove_node(pos)
+	end,
+	
+	on_rotate = screwdriver.disallow,
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+})
+
+
+minetest.register_node("techage:detector_on", {
+	description = S("TA3 Detector"),
+	tiles = {
+		-- up, down, right, left, back, front
+		"techage_filling_ta3.png^techage_frame_ta3_top.png^techage_appl_arrow.png",
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_outp.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_inp.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_detector_on.png^[transformFX",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_detector_on.png",
+	},
+
+	on_timer = switch_off,
+	on_rotate = screwdriver.disallow,
+
+	techage_set_numbers = function(pos, numbers, player_name)
+		local meta = M(pos)
+		local res = logic.set_numbers(pos, numbers, player_name, S("TA3 Detector"))
+		meta:set_string("formspec", formspec(meta))
+		return res
+	end,
+	
+	after_dig_node = function(pos, oldnode, oldmetadata, digger)
+		techage.remove_node(pos)
+	end,
+	
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2, not_in_creative_inventory=1},
+	is_ground_content = false,
+	sounds = default.node_sound_wood_defaults(),
+	drop = "techage:detector_off",
+})
+
+minetest.register_craft({
+	output = "techage:detector_off",
+	recipe = {
+		{"", "group:wood", ""},
+		{"techage:tubeS", "techage:vacuum_tube", "techage:tubeS"},
+		{"", "group:wood", ""},
+	},
+})
+
+
+techage.register_node({"techage:detector_off", "techage:detector_on"}, {
+	on_push_item = function(pos, in_dir, stack)
+		if techage.push_items(pos, in_dir, stack) then
+			switch_on(pos)
+			return true
+		end
+		return false
+	end,
+	is_pusher = true,  -- is a pulling/pushing node
+})	
+
+techage.register_entry_page("ta3l", "detector",
+	S("TA3 Detector"), 
+	S("The Detector is a special kind of tube block that@n"..
+		"outputs an event when items pass through.@n"..
+		"It sends an 'on' when an item goes through,@n"..
+		"followed by an 'off' event one second later.@n"..
+		"After that it blocks further events for 8 seconds."),
+	"techage:detector_on")
diff --git a/logic/lib.lua b/logic/lib.lua
new file mode 100644
index 0000000..c7d317d
--- /dev/null
+++ b/logic/lib.lua
@@ -0,0 +1,73 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2019 Joachim Stolberg
+
+	GPL v3
+	See LICENSE.txt for more information
+
+	Logic library
+	
+]]--
+
+-- for lazy programmers
+local M = minetest.get_meta
+local S = techage.S
+
+techage.logic = {}
+
+function techage.logic.swap_node(pos, name)
+	local node = minetest.get_node(pos)
+	if node.name == name then
+		return
+	end
+	node.name = name
+	minetest.swap_node(pos, node)
+end
+
+function techage.logic.after_place_node(pos, placer, name, descr)
+	local meta = M(pos)
+	local own_num = techage.add_node(pos, name)
+	meta:set_string("node_number", own_num)
+	meta:set_string("owner", placer:get_player_name())
+	meta:set_string("infotext", descr.." -")
+end
+
+function techage.logic.send_on(pos, meta, time)
+	local own_num = meta:get_string("node_number") or ""
+	local numbers = meta:get_string("numbers") or ""
+	if time and time > 0 then
+		minetest.get_node_timer(pos):start(time)
+	end
+	techage.send_multi(numbers, "on", own_num)
+end
+
+function techage.logic.send_off(pos, meta)
+	local own_num = meta:get_string("node_number") or ""
+	local numbers = meta:get_string("numbers") or ""
+	techage.send_multi(numbers, "off", own_num)
+end
+
+function techage.logic.infotext(meta, descr, text)
+	local own_num = meta:get_string("node_number") or ""
+	local numbers = meta:get_string("numbers") or ""
+	if numbers ~= "" then
+		meta:set_string("infotext", descr.." "..own_num..": "..S("connected with").." "..numbers)
+	elseif text then
+		meta:set_string("infotext", descr.." "..own_num..": "..text)
+	else
+		meta:set_string("infotext", descr.." "..own_num)
+	end
+end
+
+function techage.logic.set_numbers(pos, numbers, player_name, descr)
+	if techage.check_numbers(numbers, player_name) then
+		local meta = M(pos)
+		meta:set_string("numbers", numbers)
+		techage.logic.infotext(meta, descr)
+		return true
+	end
+	return false
+end
\ No newline at end of file
diff --git a/logic/programmer.lua b/logic/programmer.lua
new file mode 100644
index 0000000..657c140
--- /dev/null
+++ b/logic/programmer.lua
@@ -0,0 +1,108 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2017-2019 Joachim Stolberg
+
+	GPL v3
+	See LICENSE.txt for more information
+
+	Number programmer
+	
+]]--
+
+-- for lazy programmers
+local M = minetest.get_meta
+local S = techage.S
+
+local function join_to_string(tbl)
+	local t = {}
+	for key,_ in pairs(tbl) do
+		t[#t + 1] = key
+	end
+	return table.concat(t, " ")
+end
+
+local function reset_programmer(itemstack, user, pointed_thing)
+	user:set_attribute("techage_prog_numbers", nil)
+	minetest.chat_send_player(user:get_player_name(), S("[Techage Programmer] programmer reset"))
+	return itemstack
+end	
+
+local function read_number(itemstack, user, pointed_thing)
+	local pos = pointed_thing.under
+	if pos then
+		local number = techage.get_node_number(pos)
+		if number then
+			local numbers = minetest.deserialize(user:get_attribute("techage_prog_numbers")) or {}
+			numbers[number] = true
+			user:set_attribute("techage_prog_numbers", minetest.serialize(numbers))
+			minetest.chat_send_player(user:get_player_name(), S("[Techage Programmer] number").." "..number.." read")
+		else
+			minetest.chat_send_player(user:get_player_name(), S("[Techage Programmer] Unknown node on").." "..minetest.pos_to_string(pos))
+		end
+	else
+		return reset_programmer(itemstack, user, pointed_thing)
+	end
+	return itemstack
+end
+
+local function program_numbers(itemstack, placer, pointed_thing)
+	local pos = pointed_thing.under
+	if pos then
+		local meta = M(pos)
+		local numbers = minetest.deserialize(placer:get_attribute("techage_prog_numbers")) or {}
+		placer:set_attribute("techage_prog_numbers", nil)
+		local player_name = placer:get_player_name()
+		if meta and meta:get_string("owner") ~= player_name then
+			minetest.chat_send_player(player_name, S("[Techage Programmer] foreign or unknown node!"))
+			return itemstack
+		end
+		local text = join_to_string(numbers)
+		local ndef = minetest.registered_nodes[minetest.get_node(pos).name]
+		if ndef and ndef.techage_set_numbers then
+			local res = ndef.techage_set_numbers(pos, text, player_name)
+			if res == true then
+				minetest.chat_send_player(player_name, S("[Techage Programmer] node programmed!"))
+			else
+				minetest.chat_send_player(player_name, S("[Techage Programmer] Error: invalid numbers!"))
+			end
+		else
+			minetest.chat_send_player(player_name, S("[Techage Programmer] Error: programmer not supported!"))
+		end
+		return itemstack
+	else
+		return reset_programmer(itemstack, placer, pointed_thing)
+	end
+end
+
+minetest.register_craftitem("techage:programmer", {
+	description = S("Techage Programmer (right = read number, left = write numbers)"),
+	inventory_image = "techage_programmer.png",
+	stack_max = 1,
+	wield_image = "techage_programmer_wield.png",
+	groups = {cracky=1, book=1},
+	-- left mouse button = program
+	on_use = program_numbers,
+	on_secondary_use = reset_programmer,
+	-- right mouse button = read
+	on_place = read_number,
+})
+
+minetest.register_craft({
+	output = "techage:programmer",
+	recipe = {
+		{"", "default:steel_ingot", ""},
+		{"", "techage:wlanchip",    ""},
+		{"", "dye:red",             ""},
+	},
+})
+
+techage.register_entry_page("ta3l", "programmer",
+	S("Techage Programmer"), 
+	S("The Programmer is a tool to collect block numbers (right mouse button)@n"..
+		"from machines/nodes to program (left mouse button) the Repeater@n"..
+		"or other nodes. This is especially useful if you want to switch on/off@n"..
+		"many block at the same time."),
+	"techage:programmer")
diff --git a/logic/repeater.lua b/logic/repeater.lua
new file mode 100644
index 0000000..422c273
--- /dev/null
+++ b/logic/repeater.lua
@@ -0,0 +1,118 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2017-2019 Joachim Stolberg
+
+	GPL v3
+	See LICENSE.txt for more information
+
+	Signal Repeater
+	
+]]--
+
+-- for lazy programmers
+local M = minetest.get_meta
+local S = techage.S
+
+local logic = techage.logic
+local OVER_LOAD_MAX = 10
+local CYCLE_TIME = 2
+
+local function formspec(meta)
+	local numbers = meta:get_string("numbers") or ""
+	return "size[7.5,3]"..
+		"field[0.5,1;7,1;numbers;"..S("Insert destination node number(s)")..";"..numbers.."]" ..
+		"button_exit[2,2;3,1;exit;"..S("Save").."]"
+end
+
+minetest.register_node("techage:repeater", {
+	description = S("TA3 Repeater"),
+	tiles = {
+		-- up, down, right, left, back, front
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3_top.png",
+		"techage_filling_ta3.png^techage_frame_ta3.png^techage_appl_repeater.png",
+	},
+
+	after_place_node = function(pos, placer)
+		local meta = M(pos)
+		local mem = tubelib2.get_mem(pos)
+		logic.after_place_node(pos, placer, "techage:repeater", S("TA3 Repeater"))
+		logic.infotext(meta, S("TA3 Repeater"))
+		meta:set_string("formspec", formspec(meta))
+		mem.overload_cnt = 0
+		minetest.get_node_timer(pos):start(CYCLE_TIME)
+	end,
+
+	on_receive_fields = function(pos, formname, fields, player)
+		local meta = M(pos)
+		if techage.check_numbers(fields.numbers, player:get_player_name()) then
+			meta:set_string("numbers", fields.numbers)
+			logic.infotext(M(pos), S("TA3 Repeater"))
+			meta:set_string("formspec", formspec(meta))
+		end
+	end,
+	
+	on_timer = function(pos,elapsed)
+		local mem = tubelib2.get_mem(pos)
+		mem.overload_cnt = 0
+		return true
+	end,
+	
+	techage_set_numbers = function(pos, numbers, player_name)
+		local meta = M(pos)
+		local res = logic.set_numbers(pos, numbers, player_name, S("TA3 Repeater"))
+		meta:set_string("formspec", formspec(meta))
+		return res
+	end,
+	
+	after_dig_node = function(pos)
+		techage.remove_node(pos)
+	end,
+
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=2, cracky=2, crumbly=2},
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+})
+
+
+minetest.register_craft({
+	output = "techage:repeater",
+	recipe = {
+		{"", "group:wood", ""},
+		{"techage:vacuum_tube", "", "techage:vacuum_tube"},
+		{"", "group:wood", ""},
+	},
+})
+
+techage.register_node({"techage:repeater"}, {
+	on_recv_message = function(pos, topic, payload)
+		local mem = tubelib2.get_mem(pos)
+		mem.overload_cnt = (mem.overload_cnt or 0) + 1
+		if mem.overload_cnt > OVER_LOAD_MAX then
+			logic.infotext(M(pos), S("TA3 Repeater"), "fault (overloaded)")
+			minetest.get_node_timer(pos):stop()
+			return false
+		else
+			local numbers = M(pos):get_string("numbers") or ""
+			techage.send_multi(numbers, topic, payload)
+		end
+	end,
+	on_node_load = function(pos)
+		minetest.get_node_timer(pos):start(CYCLE_TIME)
+	end,
+})		
+
+techage.register_entry_page("ta3l", "repeater",
+	S("TA3 Repeater"), 
+	S("The Repeater is a multiplier block, sending received commands@n"..
+		"to all connected blocks. The list of destination block numbers@n"..
+		"has to be configured, but can easily programmed@n"..
+		"by means of the Programmer."),
+	"techage:repeater")
+
diff --git a/logic/terminal.lua b/logic/terminal.lua
index 5bde164..f184697 100644
--- a/logic/terminal.lua
+++ b/logic/terminal.lua
@@ -12,6 +12,7 @@
 	
 ]]--
 
+local M = minetest.get_meta
 local S = techage.S
 
 local HELP_TA3 = S("#### TA3 Terminal ####@n"..
@@ -40,14 +41,14 @@ local HELP_TA3 = S("#### TA3 Terminal ####@n"..
 
 local CMNDS_TA3 = S("Syntax error, try help")
 
-local function formspec1()
-	return "size[6,4]"..
-	default.gui_bg..
-	default.gui_bg_img..
-	default.gui_slots..
-	"field[0.5,1;5,1;number;Techage Controller number:;]" ..
-	"button_exit[1.5,2.5;2,1;exit;Save]"
-end
+--local function formspec1()
+--	return "size[6,4]"..
+--	default.gui_bg..
+--	default.gui_bg_img..
+--	default.gui_slots..
+--	"field[0.5,1;5,1;number;Techage Controller number:;]" ..
+--	"button_exit[1.5,2.5;2,1;exit;Save]"
+--end
 
 local function get_string(meta, num, default)
 	local s = meta:get_string("bttn_text"..num)
@@ -127,7 +128,6 @@ local function command(pos, command, player)
 			output(pos, "$ "..command)
 			local num, cmnd, payload = command:match('^cmd%s+([0-9]+)%s+(%w+)%s*(.*)$')
 			if num and cmnd then
-				local own_number = meta:get_string("own_number")
 				if techage.not_protected(num, owner, owner) then
 					local resp = techage.send_single(num, cmnd, payload)
 					if type(resp) == "string" then
@@ -177,7 +177,7 @@ local function register_terminal(num, tiles, node_box, selection_box)
 		after_place_node = function(pos, placer)
 			local number = techage.add_node(pos, minetest.get_node(pos).name)
 			local meta = minetest.get_meta(pos)
-			meta:set_string("own_number", number)
+			meta:set_string("node_number", number)
 			meta:set_string("command", S("commands like: help"))
 			meta:set_string("formspec", formspec2(meta))
 			meta:set_string("owner", placer:get_player_name())
@@ -284,12 +284,15 @@ minetest.register_craft({
 
 techage.register_node({"techage:terminal1", "techage:terminal2"}, {
 	on_recv_message = function(pos, topic, payload)
-		if topic == "term" then
-			output(pos, payload)
-			return true
-		elseif topic == "msg" then
-			output(pos, payload.src..": "..payload.text)
-			return true
+		output(pos, "cmd="..dump(topic)..", data="..dump(payload))
+		return true
+	end,
+	on_node_load = function(pos)
+		local meta = M(pos)
+		local number = meta:get_string("number") or ""
+		if number ~= "" then
+			meta:set_string("node_number", number)
+			meta:set_string("number", nil)
 		end
 	end,
 })
diff --git a/power/powerswitch.lua b/power/powerswitch.lua
index 05bd695..e7d7d71 100644
--- a/power/powerswitch.lua
+++ b/power/powerswitch.lua
@@ -80,9 +80,9 @@ minetest.register_node("techage:powerswitch", {
 	},
 	
 	after_place_node = function(pos, placer)
-		local meta = minetest.get_meta(pos)
+		local meta = M(pos)
 		local number = techage.add_node(pos, "techage:powerswitch")
-		meta:set_string("number", number)
+		meta:set_string("node_number", number)
 		meta:set_string("owner", placer:get_player_name())
 		meta:set_string("infotext", S("TA Power Switch").." "..number)
 	end,
@@ -212,6 +212,14 @@ techage.register_node({"techage:powerswitch", "techage:powerswitch_on"}, {
 			return "unsupported"
 		end
 	end,
+	on_node_load = function(pos)
+		local meta = M(pos)
+		local number = meta:get_string("number") or ""
+		if number ~= "" then
+			meta:set_string("node_number", number)
+			meta:set_string("number", nil)
+		end
+	end,
 })	
 
 minetest.register_craft({
diff --git a/solar/minicell.lua b/solar/minicell.lua
index 281818b..65b375d 100644
--- a/solar/minicell.lua
+++ b/solar/minicell.lua
@@ -83,7 +83,7 @@ minetest.register_node("techage:ta4_solar_minicell", {
 	after_place_node = function(pos)
 		local meta = minetest.get_meta(pos)
 		local number = techage.add_node(pos, "techage:ta4_solar_minicell")
-		meta:set_string("number", number)
+		meta:set_string("node_number", number)
 		meta:set_string("infotext", S("TA4 Streetlamp Solar Cell").." "..number)
 		local mem = tubelib2.get_mem(pos)
 		mem.capa = 0
@@ -121,6 +121,14 @@ techage.register_node({"techage:ta4_solar_minicell"}, {
 			return "unsupported"
 		end
 	end,
+	on_node_load = function(pos)
+		local meta = M(pos)
+		local number = meta:get_string("number") or ""
+		if number ~= "" then
+			meta:set_string("node_number", number)
+			meta:set_string("number", nil)
+		end
+	end,
 })
 
 minetest.register_craft({
diff --git a/textures/techage_appl_button.png b/textures/techage_appl_button.png
new file mode 100644
index 0000000..99f30dd
Binary files /dev/null and b/textures/techage_appl_button.png differ
diff --git a/textures/techage_appl_detector.png b/textures/techage_appl_detector.png
new file mode 100644
index 0000000..05dc45d
Binary files /dev/null and b/textures/techage_appl_detector.png differ
diff --git a/textures/techage_appl_detector_on.png b/textures/techage_appl_detector_on.png
new file mode 100644
index 0000000..0d05fb7
Binary files /dev/null and b/textures/techage_appl_detector_on.png differ
diff --git a/textures/techage_appl_repeater.png b/textures/techage_appl_repeater.png
new file mode 100644
index 0000000..37b5bad
Binary files /dev/null and b/textures/techage_appl_repeater.png differ
diff --git a/textures/techage_button_off.png b/textures/techage_button_off.png
new file mode 100644
index 0000000..0d65841
Binary files /dev/null and b/textures/techage_button_off.png differ
diff --git a/textures/techage_button_on.png b/textures/techage_button_on.png
new file mode 100644
index 0000000..68f9f24
Binary files /dev/null and b/textures/techage_button_on.png differ
diff --git a/textures/techage_programmer.png b/textures/techage_programmer.png
new file mode 100644
index 0000000..03a08d7
Binary files /dev/null and b/textures/techage_programmer.png differ
diff --git a/textures/techage_programmer_wield.png b/textures/techage_programmer_wield.png
new file mode 100644
index 0000000..7a6866c
Binary files /dev/null and b/textures/techage_programmer_wield.png differ
diff --git a/tools/repairkit.lua b/tools/repairkit.lua
index e7d88d2..8ab3481 100644
--- a/tools/repairkit.lua
+++ b/tools/repairkit.lua
@@ -1,7 +1,7 @@
 --[[
 
-	TexchAge
-	========
+	TechAge
+	=======
 
 	Copyright (C) 2017-2019 Joachim Stolberg