diff --git a/programs.info b/programs.info
index 476f8f4..441c14b 100644
--- a/programs.info
+++ b/programs.info
@@ -58,6 +58,13 @@
             "libgpu","libevent","simple_data_structure"
         }
     },
+    ["shrink"]={
+        title="Shrink",
+        info="Shrink string by removing useless spaces.",
+        files={
+            "shrink.lua"
+        }
+    },
     ["drone"]={
         title="Drone",
         info="Drone console and bios",
@@ -65,10 +72,12 @@
         contact="1362050620@qq.com",
         files={
             ["programs/drone/drone_bios.lua"]="drone_bios.lua",
-            ["programs/drone/drone_console.lua"]="drone_console.lua"
+            ["programs/drone/drone_console.lua"]="drone_console.lua",
+            ["programs/drone/drone_radar.lua"]="drone_radar.lua",
+            ["programs/drone/drone_flash.lua"]="drone_flash.lua"
         },
         requires={
-            "libevent"
+            "libevent", "shrink"
         }
     },
     ["smartstorage"]={
diff --git a/programs/drone/drone_bios.lua b/programs/drone/drone_bios.lua
index 0a96ba2..94018bd 100644
--- a/programs/drone/drone_bios.lua
+++ b/programs/drone/drone_bios.lua
@@ -1,6 +1,6 @@
+drone_version="Drone v3.3b"
 drone=component.proxy(component.list("drone")())
 modem=component.proxy(component.list("modem")())
-drone_version="Drone v3.2"
 drone.setStatusText(drone_version .. '\n' .. modem.address)
 modem.open(98)
 handlers={}
@@ -8,39 +8,67 @@ timers={}
 wake_list={}
 handlers["_anything"]={}
 handle_event=function(e)
-    if(handlers[e[1]]) then for i,tb in pairs(handlers[e[1]]) do coroutine.resume(tb.co,i,e) end end
-    for i,tb in pairs(handlers["_anything"]) do coroutine.resume(tb.co,i,e) end
+    if(handlers[e[1]]) then 
+        for i,tb in pairs(handlers[e[1]]) do 
+            coroutine.resume(tb.co,i,e) 
+        end
+    end
+    for i,tb in pairs(handlers["_anything"]) do 
+        coroutine.resume(tb.co,i,e)
+    end
 end
 sleep=function(sec)
-    local this,flag=coroutine.running()
-    table.insert(wake_list,{id=0,tm=computer.uptime()+sec,co=this})
-    local this_id=coroutine.yield()
-    table.remove(wake_list,this_id)
+    table.insert(wake_list,{id=0,tm=computer.uptime()+sec,co=coroutine.running()})
+    table.remove(wake_list,coroutine.yield())
 end
-cancel=function(id)
-    if(timers[id]) then for i,t in ipairs(wake_list) do if(t.id==id) then table.remove(wake_list,i) break end end timers[id]=nil return true 
-    else return false end
+cancel=function(id,wid)
+    if(wid) then 
+        table.remove(wake_list,wid) 
+    else 
+        for i,t in ipairs(wake_list) do 
+            if(t.id==id) then 
+                table.remove(wake_list,i) 
+                break 
+            end 
+        end
+    end
+    if(timers[id]) then 
+        timers[id]=nil 
+        return true
+    else 
+        return false 
+    end
 end
 timer=function(sec,fn,times)
-    local next=computer.uptime()+sec
-    local id=table.insert(timers,{cb=fn,intv=sec,times=times})
-    table.insert(wake_list,{tm=next,id=id,co=coroutine.create(function(this_id)
+    table.insert(timers,{cb=fn,intv=sec,times=times})
+    local id=#timers
+    table.insert(wake_list,{tm=computer.uptime()+sec,id=id,co=coroutine.create(function(wid)
         while true do 
-            pcall(fn) 
-            local this_tb=timers[this.id]
-            if(this_tb.times>0) then this_tb.times=this_tb.times-1 
-                if(this_tb.times<1) then timer[wake_list[this_id].id]=nil table.remove(wake_list,this_id) return
-                else this.tm=computer.uptime()+this_tb.intv this_id=coroutine.yield() end
+            pcall(fn)
+            local tb=timers[id]
+            if(tb.times<0 or tb.times>1) then 
+                tb.times,tb.tm=tb.times-1,computer.uptime()+tb.intv
+                wid=coroutine.yield()
+            else
+                cancel(id,wid)
+                return
             end
         end
     end)})
     return id
 end
 ignore=function(name,id)
-    handlers[name][id]=nil
+    if(handlers[name][id]) then 
+        handlers[name][id]=nil 
+        return true
+    else 
+        return false 
+    end
 end
 listen=function(name,cb)
-    if(handlers[name]==nil) then handlers[name]={} end
+    if(handlers[name]==nil) then 
+        handlers[name]={}
+    end
     table.insert(handlers[name],{co=coroutine.create(function(i,e)
         while true do
             local ok,res=pcall(cb,e)
@@ -54,28 +82,27 @@ listen=function(name,cb)
     return #handlers[name]
 end
 wait=function(sec,name)
-    if(sec==nil and name==nil) then sec=-1 
-    elseif(sec==nil and name~=nil) then sec=-1
-    elseif(sec~=nil and name==nil) then if(type(sec)=="string") then name=sec sec=-1 end end
-    local this,flag=coroutine.running()
-    if(sec>=0) then
-        table.insert(wake_list,{id=0,tm=computer.uptime()+sec,co=this})
-    else
-        table.insert(wake_list,{id=0,tm=math.huge,co=this})
-    end
-    local id
-    if(name~=nil) then
-        id=listen(name,function(e) if(e[1]==name) then coroutine.resume(this,-1,e) return false end end)
-    else
-        id=listen("_anything",function(e) coroutine.resume(this,-1,e) return false end)
-    end
-    local this_id,e=coroutine.yield()
-    if(this_id==-1) then
-        for idx,t in ipairs(wake_list) do if(t.co==this) then table.remove(wake_list,idx) end end
+    if(name==nil and type(sec)=="string") then name=sec sec=nil end
+    sec=sec and computer.uptime()+sec or math.huge
+    local this=coroutine.running()
+    table.insert(wake_list,{id=0,tm=sec,co=this})
+    name=name or "_anything"
+    local id=listen(name,function(e) 
+        coroutine.resume(this,-1,e)
+        return false
+    end)
+    local wid,e=coroutine.yield()
+    ignore(name,id)
+    if(wid==-1) then
+        for i,t in ipairs(wake_list) do 
+            if(t.co==this) then 
+                table.remove(wake_list,i)
+                break
+            end
+        end
         return e
     else
-        ignore(id)
-        table.remove(wake_list,this_id)
+        table.remove(wake_list,wid)
         return nil
     end
 end
@@ -83,25 +110,26 @@ listen("modem_message",function(e)
     local snd=e[3]
     local tag=e[6]
     local cmd=e[7]
-    if(tag~=nil and cmd~=nil and tag=='execute_command') then 
-        local ok,err=pcall(function() 
-            local f=load(cmd)
-            local cmdok,cmdresult=pcall(f)
-            if(not cmdok) then
-                modem.send(snd,99,"Failed to execute: " .. cmdresult)
+    if(tag and tag=='execute_command' and cmd) then 
+        local f,err=load(cmd)
+        if(f) then
+            local ok,err=pcall(f)
+            if(not ok) then 
+                modem.send(snd,99,"CallError: " .. res)
             else
-                modem.send(snd,99,cmdresult)
+                modem.send(snd,99,res)
             end
-        end)
-        if(not ok) then
-            modem.send(snd,99,"Command Execute Failed: " .. err)
+        else
+            modem.send(snd,99,"SyntaxError: " .. err)
         end
     end
 end)
 while true do
     local max_wait,max_id=math.huge,0
     for i,v in ipairs(wake_list) do
-        if(v.tm<max_wait) then max_wait,max_id=v.tm,i end
+        if(v.tm<max_wait) then 
+            max_wait,max_id=v.tm,i
+        end
     end
     local e
     if(max_wait==math.huge) then
diff --git a/programs/drone/drone_console.lua b/programs/drone/drone_console.lua
index f6d569e..574b59a 100644
--- a/programs/drone/drone_console.lua
+++ b/programs/drone/drone_console.lua
@@ -108,7 +108,7 @@ function helper.setRadar(enable)
 end
 helper.target_drone=''
 function helper.install_step1()
-    modem.broadcast(98,"modem.send('" .. modem.address .. "',99,'hide_msg','prepare_for_install')")
+    modem.broadcast(98,"execute_command","modem.send('" .. modem.address .. "',99,'hide_msg','prepare_for_install')")
     while true do
         local e=WaitEvent(5,"modem_message")
         if(e==nil) then 
@@ -126,8 +126,12 @@ function helper.install_step1()
     return false
 end
 helper.drone_lib=[==[
-    drone_lib_version='DroneLib v0.1'
-    
+    drone_lib_version='DroneLib v0.1.1'
+    move=function(x,y,z,t)
+        t=t or 5
+        drone.move(x,y,z) 
+        while drone.getOffset()>1 do sleep(t) end
+    end
     return drone_lib_version .. " successfully installed."
 ]==]
 function helper.install_step2()
@@ -135,7 +139,7 @@ function helper.install_step2()
         SetResponse("[Local] Install step 2: About to perform installation on " .. helper.target_drone)
         os.sleep(1)
         SetResponse("[Local] Install step 2: Sending data to " .. helper.target_drone)
-        modem.send(helper.target_drone,98,helper.drone_lib)
+        modem.send(helper.target_drone,98,"execute_command",helper.drone_lib)
     end
 end
 
diff --git a/programs/drone/drone_flash.lua b/programs/drone/drone_flash.lua
new file mode 100644
index 0000000..9c2ea84
--- /dev/null
+++ b/programs/drone/drone_flash.lua
@@ -0,0 +1,44 @@
+-- Drone Flash
+-- Created by Kiritow
+local component=require('component')
+local shrink=require('shrink')
+require('libevent')
+print("Please insert new eeprom. (Or press Ctrl+C if the eeprom is already inserted.)")
+while true do
+    local e=WaitMultipleEvent("interrupted","component_added")
+    if(e.event=="interrupted" or (e.event=="component_added" and e.componentType=="eeprom")) then 
+        break
+    end
+end
+print("[Working] Reading drone bios from disk...")
+local f=io.open("drone_bios.lua","r")
+if(not f) then 
+    print("[Error] Unable to open drone_bios.lua.")
+    return 
+end
+local data=f:read("a")
+f:close()
+print("Original data size: " .. string.len(data))
+print("[Working] Syntax checking...")
+local xt={}
+local fn,err=load(data,"DroneBios","t",xt)
+if(not fn) then
+    print("Found syntax error: " .. err)
+    return
+end
+print("[Working] Getting DroneBios version...")
+pcall(fn)
+local drone_bios_version=xt['drone_version']
+if(not drone_bios_version) then 
+    print("[Error] Unable to get version tag.")
+    return
+end
+print("Version tag: " .. drone_bios_version)
+print("[Working] Shrinking...")
+data=shrink(data)
+print("Shrank data size: " .. string.len(data))
+print("[Working] Writing to eeprom...")
+component.eeprom.set(data)
+print("[Working] Setting eeprom label...")
+component.eeprom.setLabel(drone_bios_version)
+print("[Done] Remember to insert the original eeprom!")
\ No newline at end of file
diff --git a/programs/drone/drone_radar.lua b/programs/drone/drone_radar.lua
new file mode 100644
index 0000000..5605871
--- /dev/null
+++ b/programs/drone/drone_radar.lua
@@ -0,0 +1,105 @@
+-- Drone Radar
+-- Created by Kiritow.
+local component=require('component')
+local computer=require('computer')
+local term=require('term')
+local text=require('text')
+
+require("libevent")
+
+local radar_version="Drone Radar v0.1.3"
+local modem=component.modem
+local gpu=term.gpu()
+
+local function status(msg)
+    local w,h=gpu.getResolution()
+    gpu.set(1,h,"Status: " .. msg)
+end
+
+term.clear()
+print("Drone Radar")
+print("Checking hardware...")
+if(modem==nil) then
+    print("This program requires a modem component to work")
+    return
+end
+print("Opening modem port...")
+if(not modem.open(99)) then
+    if(modem.isOpen(99)) then
+        print("Port 99 is already opened.")
+    else
+        print("Unable to open port 99.")
+        return
+    end
+end
+print("Adding timer...")
+local broadcast_intv=8
+local timer=AddTimer(broadcast_intv,function()
+    modem.broadcast(98,"execute_command","modem.send('" .. modem.address .. "',99,'radar_info',drone.getOffset(),computer.energy())")
+end,-1)
+print("Adding listener...")
+local tb_drone={}
+local listener=AddEventListener("modem_message",function(e)
+    if(e.port==99 and e.data[1]=='radar_info') then
+        tb_drone[e.senderAddress]={
+            distance=e.distance,
+            offset=e.data[2],
+            energy=e.data[3],
+            update=computer.uptime()
+        }
+        PushEvent("radar_gui_update")
+    end
+end)
+
+local function show_tb(tb)
+    local maxLen={}
+    for idx,v in ipairs(tb) do 
+        for nidx,val in ipairs(v) do
+            if(not maxLen[nidx] or maxLen[nidx]<string.len(val)) then
+                maxLen[nidx]=string.len(val)
+            end
+        end
+    end
+    for idx,v in ipairs(tb) do
+        for nidx,val in ipairs(v) do
+            v[nidx]=text.padRight(val,maxLen[nidx])
+        end
+        print(table.concat(v," "))
+    end
+end
+
+term.clear()
+print(radar_version)
+
+while true do
+    term.setCursor(1,2)
+    local now=computer.uptime()
+    local show={}
+    table.insert(show,{"Address","Status","Distance","Offset","Energy"})
+    for addr,tb in pairs(tb_drone) do
+        local newt={string.sub(addr,1,8),"[Missing]",string.format("%.1f",tb.distance),string.format("%.1f",tb.offset),string.format("%.1f",tb.energy)}
+        if(now-tb.update<broadcast_intv) then 
+            if(tb.offset<1) then
+                newt[2]="[OK]"
+            else
+                newt[2]="[Flying]"
+            end
+        end
+        table.insert(show,newt)
+
+        if(now-tb.update>broadcast_intv*2.5) then
+            tb_drone[addr]=nil
+        end
+    end
+    show_tb(show)
+    local e=WaitMultipleEvent("interrupted","radar_gui_update")
+    if(e.event=="interrupted") then break end
+end
+
+term.clear()
+print("Stopping listener...")
+RemoveEventListener(listener)
+print("Stopping timer...")
+RemoveTimer(timer)
+print("Closing port...")
+modem.close(99)
\ No newline at end of file