100xxx - string functions
100000 ----- strlen (string.pvvs)
100001 ----- isdigit (string.pvvs)
+ 100010 ----- get_user_string (string.pvvs)
101xxx - logic functions
101000 ----- not (logic.pvvs)
101001 ----- and (logic.pvvs)
111011 ----- print magnitude (debug.pvvs)
111100 ----- print string (debug.pvvs)
111101 ----- print signed number (debug.pvvs)
+ 111110 ----- stdlib version (debug.pvvs)
1xxxxxx - reserved for less common entry points
1000000 ----- lowbitand (logic.pvvs)
1000001 ----- <empty>