+ 011xxx - heap functions
+ 11000 ----- memset (heap.pvvs)
+ 11001 ----- memcpy (heap.pvvs)
+ 11010 ----- memrand (heap.pvvs)
+ 11011 ----- memcmp (heap.pvvs)
+ 11100 ----- memsrch (heap.pvvs)
+ 11101 ----- <empty>
+ 11110 ----- slurp (heap.pvvs)
+ 11111 ----- spew (heap.pvvs)
+ 100xxx - string functions
+ 100000 ----- strlen (string.pvvs)
+ 101xxx - logic functions
+ 101000 ----- not (logic.pvvs)
+ 101001 ----- and (logic.pvvs)
+ 101010 ----- or (logic.pvvs)
+ 101011 ----- xor (logic.pvvs)
+ 101100 ----- rshift (logic.pvvs)
+ 101101 ----- lshift (logic.pvvs)
+ 110xxx - conversion functions
+ 111xxx - debug functions
+ 111000 ----- dump heap (debug.pvvs)
+ 111001 ----- dump stack (debug.pvvs)
+ 111010 ----- print sign (debug.pvvs)
+ 111011 ----- print magnitude (debug.pvvs)
+ 111100 ----- print string (debug.pvvs)