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 ----- <empty>