Added a memory node, stores 16 values and takes into account an offset.

It's accessed using a channel in the form of sending a digiline message:
Channel: <prefix><address + offset>
Message:
 - For read: "get"
 - For write: a number (it doesn't really mind beyond that)

test3d_t416/depends.txt

@@ -0,0 +1,2 @@
+default
+digilines

test3d_t416/init.lua

@@ -0,0 +1,80 @@
+local MEMSIZE=16
+if not digiline then
+ print("Digilines not found.")
+ return
+end
+local oldprint=print
+local function print(...)
+ for k,v in ipairs({...}) do
+  oldprint("[Test3D:T416] "..tostring(v))
+ end
+end
+print("Loading.")
+
+local function t416_digiline_receive(pos, node, channel, msg)
+ print("Digiline: "..tostring(pos.x)..","..tostring(pos.y)..","..tostring(pos.z).."; Channel: "..tostring(channel).."; Message: "..tostring(msg))
+ local meta = minetest.get_meta(pos)
+ local mem = string.split(meta:get_string("mem"),"\n")
+ local ms = ""
+ local chan = meta:get_string("channel")
+ local memoffset = meta:get_int("startaddr")
+ if channel:sub(1,#chan) == chan and tonumber(channel:sub(#chan+1),16)+1-memoffset <= MEMSIZE and tonumber(channel:sub(#chan+1),16)+1-memoffset > 0 then
+  local memaddr = tonumber(channel:sub(#chan+1),16)+1-memoffset
+  print(memaddr)
+  if tostring(msg):lower() == "get" then
+   digiline:receptor_send(pos, digiline.rules.default, channel, tonumber(mem[memaddr] or 0))
+   print("Reading address "..tostring(memaddr)..": "..tostring(mem[memaddr]))
+  else
+   mem[memaddr] = tonumber(msg) or 0
+   for k,v in ipairs(mem) do
+    ms = ms .. tostring(v) .. "\n"
+   end
+   meta:set_string("mem",ms)
+   print("Set address "..tostring(memaddr).." to "..tostring(tonumber(msg)))
+  end
+ end
+end
+print("Created T416 digiline function")
+
+local function t416_set_meta(pos)
+ local meta = minetest.get_meta(pos)
+ local ms = ""
+ for i = 1, 16 do
+  ms = ms .. "0\n"
+ end
+ meta:set_string("mem",ms)
+ meta:set_string("channel","Default")
+ meta:set_int("startaddr",0)
+ meta:set_string("formspec","size[5,12]\nlabel[0.4,0.5;T416 Memory Node (16 words)]\nfield[0.5,2;4,1;channel;Channel prefix;${channel}]\nfield[0.5,3;4,1;startaddr;Starting address;${startaddr}]\ntextarea[0.5,4;4,8;mem;Memory contents;${mem}]")
+end
+minetest.register_node("test3d_t416:t416", {
+ description = "T416 Memory Node",
+ tiles = {
+  {
+   image="t416.png",
+   animation={
+    type = "vertical_frames",
+    aspect_w=16,
+    aspect_h=16,
+    length=18,
+    length=1.8,
+   },
+  },
+ },
+ on_construct = t416_set_meta,
+ groups = {snappy=1,choppy=2,oddly_breakable_by_hand=2,flammable=3},
+ digiline = {
+  receptor = {},
+  effector = {
+   action = t416_digiline_receive
+  }
+ },
+ on_receive_fields = function(pos,_,fields,sender)
+  if fields.channel == nil then return end
+  local meta = minetest.get_meta(pos)
+  fields.channel = fields.channel or ""
+  meta:set_string("channel",fields.channel)
+  meta:set_int("startaddr",tonumber(fields.startaddr))
+ end
+})
+print("T416 node registered")