111010 ----- print sign (debug.pvvs)
111011 ----- print magnitude (debug.pvvs)
111100 ----- print string (debug.pvvs)
+ 111101 ----- print signed number (debug.pvvs)
1xxxxxx - reserved for less common entry points
1000000 ----- lowbitand (logic.pvvs)
- 1000001 ----- isnegative (math.pvvs)
+ 1000001 ----- <empty>
1000010 ----- print sign of number (stdio.pvvs)
1000011 ----- print magnitude of number (stdio.pvvs)
1000100 ----- print string from stack (stdio.pvvs)