tron - turn on execution tracing
troff - turn off execution tracing


tron .  .  . 


Tron and troff are debugging aids.  Tron turns on tracing and troff turns it off.  When tracing is on, each program line number is printed within square brackets as it is executed.  Unnumbered lines are displayed as having line number 0. 


The program
	10 tron
	20 i = 11
	30 for j = 1 to 2
	40	k = i + 10
	50	print i; j; k
	60	i = i + 10
	70 next
	80 troff
	90 end
produces the output
	[10][20][30][40] 11 1 21
	[50][60][30][40] 21 2 31
This example uses tron to trace execution of a loop.  The numbers in brackets are line numbers which constitute the trace.  All other output is produced by the print statement in the program. 


If the program is compiled with the "-L" option, tron and troff may not be used.  The "-L" option is used to decrease the size of the compiled Basmark QuickBASIC program by omitting information about program line numbers at run-time. 

from The Basmark QuickBASIC Programmerís Manual by Lawrence Leinweber