there is now a non-standard control code for the terminal to toggle line mode and local echo for the terminal

module/nvt100.lua

@@ -28,6 +28,7 @@ function vt100emu(gpu) -- takes GPU component proxy *gpu* and returns a function
 
  local function termwrite(s)
   local wb = ""
+  local lb, ec = nil, nil
   local function flushwb()
    while wb:len() > 0 do
     checkCursor()
@@ -103,7 +104,7 @@ function vt100emu(gpu) -- takes GPU component proxy *gpu* and returns a function
      elseif cc == "m" then
       for _,num in ipairs(tA) do
        if num == 0 then
-        fg,bg = 0xFFFFFF,0
+        fg,bg,ec,lb = 0xFFFFFF,0,true,true
        elseif num == 7 then
         local nfg,nbg = bg, fg
         fg, bg = nfg, nbg
@@ -111,6 +112,10 @@ function vt100emu(gpu) -- takes GPU component proxy *gpu* and returns a function
         fg = colours[num-29]
        elseif num > 39 and num < 48 then
         bg = colours[num-39]
+       elseif num == 100 then -- disable local echo
+        ec = false
+       elseif num == 101 then -- disable line mode
+        lb = false
        end
       end
       gpu.setForeground(fg)
@@ -129,7 +134,7 @@ function vt100emu(gpu) -- takes GPU component proxy *gpu* and returns a function
   gpu.set(cx,cy,pc)
   gpu.setForeground(fg)
   gpu.setBackground(bg)
-  return rs
+  return rs, lb, ec
  end
 
  return termwrite

module/vt-task.lua

@@ -8,7 +8,7 @@ function vtemu(gpua,scra) -- creates a process to handle the GPU and screen addr
  for k,v in ipairs(component.invoke(scra,"getKeyboards")) do
   kba[v]=true
  end
- local buf = ""
+ local buf, lbuf, echo = "", true, true
  os.spawn(function() dprint(pcall(function()
   while true do
    local ty,ka,ch = coroutine.yield()
@@ -16,24 +16,43 @@ function vtemu(gpua,scra) -- creates a process to handle the GPU and screen addr
     if ch == 13 then ch = 10 end
     if ch == 8 then
      if buf:len() > 0 then
-      write("\8 \8")
+      if echo then write("\8 \8") end
       buf = buf:sub(1,-2)
      end
     elseif ch > 0 then
-     write(string.char(ch))
+     if echo then write(string.char(ch)) end
      buf=buf..string.char(ch)
     end
    end
   end
  end)) end,string.format("ttyd[%s:%s]",gpua:sub(1,8),scra:sub(1,8)))
- local function bread()
-  while not buf:find("\n") do
+ local function bread(n)
+  local r
+  if lbuf then
+   while not buf:find("\n") do
+    coroutine.yield()
+   end
+   local n = buf:find("\n")
+   r, buf = buf:sub(1,n), buf:sub(n+1)
+  else
+   r = buf
+   buf = ""
    coroutine.yield()
   end
-  local n = buf:find("\n")
-  r, buf = buf:sub(1,n), buf:sub(n+1)
   return r
  end
- return bread, function(d) buf=buf..write(d) end, function() io.write("\27[2J\27[H") end
+ local function bwrite(d)
+  local ba, lb, ec = write(d)
+  buf = buf .. ba
+  if lb ~= nil then
+   dprint("local buffer mode: "..tostring(lb))
+   lbuf = lb
+  end
+  if ec ~= nil then
+   dprint("echo mode: "..tostring(ec))
+   echo = ec
+  end
+ end
+ return bread, bwrite, function() io.write("\27[2J\27[H") end
 end
 end