Use array objects for samples and timestamps (as two items in a DotDict per trace); put +2 back into timeout calculation logic

vm.py

@@ -13,6 +13,7 @@ document][VM01B].
 
 """
 
+import array
 import asyncio
 from collections import namedtuple
 from enum import IntEnum
@@ -356,10 +357,10 @@ class VirtualMachine:
         if sample_width == 2:
             data = await self._reader.readexactly(2 * n)
             data = struct.unpack(f'>{n}h', data)
-            return [(value+32768)/65535 for value in data]
+            return array.array('d', ((value+32768)/65535 for value in data))
         elif sample_width == 1:
             data = await self._reader.readexactly(n)
-            return [value/255 for value in data]
+            return array.array('d', (value/255 for value in data))
         else:
             raise ValueError(f"Bad sample width: {sample_width}")