Revised BASIC trace routine 

          Jay Holovacs, 74756,413 
          2/23/87 

          TRON v3.0 is the latest in a series of sporadic refinements to 
          the TRON trace routine.  As with earlier versions, it provides a 
          running line number trace of a BASIC program while running, a 
          useful programming aid. 

          TRON is now easier to use and allows you to turn on and off the 
          trace feature from the keyboard during program execution.  To 
          use TRON, store it memory as a .CO file and lower HIMEM with the 
          BASIC command: 

          CLEAR 256,62615 

          Activate TRON from the menu by selecting it with the wide 
          cursor; after a few seconds the main menu will return, TRON is 
          now active (if you hear a beep, you forgot to clear HIMEM).  
          Enter BASIC or run your program as normal.  At any point during 
          program execution hit control-T to turn on the trace and 
          control-U to turn it back off.  This can be repeated an 
          unlimited number of times.  When finished, or before loading or 
          running other machine language programs (you can have m-l 
          programs in ram as .CO files with no conflict) it is IMPORTANT 
          to 'unhook' TRON with control-X (computer will beep and a 
          printed message will confirm de-activation.)  After this is 
          done, TRON is completely inactive and must be invoked from the 
          menu to be used again.  In testing, I have not had any problems 
          leaving TRON active when using TELCOM or TEXT but it is strongly 
          recommended as a precaution to deactivate it as soon as you are 
          done working in BASIC.  If you are not sure, no harm is done by 
          pressing cntrl-X again. 

          TRON is stored on CIS in HEX format, and should be downloaded 
          with XMODEM if at all possible.  It will then be necessary to 
          convert the file into the binary file TRON.CO using CHANGE.BA 
          from DL7. 


          SAVING AND RELOADING TRON: 

          If you are using the portable disk drive it can be saved 
          directly as a .CO file.  If you are using cassette, save it to 
          tape as follows: (with TRON DEACTIVATED) 

          CLEAR 256,62515 
          LOADM"TRON.CO" 
          CSAVEM"TRON.CO",62616,62958,62634 

          Loading from tape is done from BASIC with the following commands: 

          CLEAR 256,62515 
          CLOADM"TRON.CO" 
         SAVEM"TRON.CO",62616,62958,62634
          (this loading procedure does not in itself activate TRON) 

          NOTES: 

          TRON is relatively simple and foolproof if you observe the 
          following: 

          Remember that a BASIC program that loads a Machine Language 
          routine through a  
          series of POKES can also conflict with TRON (if active). 

          ROM based programs like TEXT or TELCOM have not caused me a 
          problem, but I  
          advise being sure TRON is deactivated before using these as well. 

          Occasionally, if your program has a great deal of PRINTing 
          activity, printed strings may 'step on' some of the line numbers 
          being printed.  This does no harm. 

          Because TRON samples the program every 4 milliseconds, it is 
          possible for an occasional very fast line to slip thru, but the 
          lines on either side will be caught. 

          I have no tried it with a #102, but it should work (always save 
          your files before trying it the first time however).  If someone 
          does try it, please tell me your results via Easyplex.