1001 ----- print string from heap (stdio.pvvs)
1010 ----- print number from stack (stdio.pvvs)
010xxx - math functions
+ 10000 ----- random (math.pvvs)
10001 ----- absolute value (math.pvvs)
011xxx - unassigned
100xxx - unassigned
101xxx - unassigned
- 110xxx - unassigned
- 111xxx - conversion functions
+ 110xxx - conversion functions
+ 111xxx - debug functions
+ 111000 ----- dump heap (debug.pvvs)
1xxxxxx - reserved for less common entry points
1000000 ----- print sign of number (stdio.pvvs)
1000001 ----- print magnitude of number (stdio.pvvs)