28

Turn trace on and oft
There are two ways to turn tracing on and off: directly, from the Debug menu, orby meansof Debug points in theprogram.

The menu options which control tracing are Show Trace - TROFF and Shnw Trace - IRON. Shnw Trace - IRON turns tracing on, and Show Trace - TROFF tamsisoff again. The difference between Show Truce - TROFF and Debug enabled is that the formeraltowsthetracingtobechangedusingdebugpoints, whereas thelasseralwaysignores all tracing commands.

The tracing options in debug points sbould now be self-enplanatory. Turn on tracing sams tracing on (provided thaI one of the Show Trace optiom in selected in the Program menu) and Turn nff tracing sams it off again. If the tracing is changed by a debug point inside asubpregram or modale, it reverts to issoriginal value on exit.

However, debug points which turn racing off can be overridden. The last two items on the Program menu are <<TROFF>> enabled and <<TROFF>> dinabled.Whenthesecondof these is selected, all <TROFF>> debug points are ignored.

Single Step
Single slep modeenablea you toexeeute yourprogram one statementala time.

If you startaprogram by selecting the second item on theProgram menu— Start Step tbeeption Single Step wiltautomaticallybeselectedin thelewerpartofthalmenubefere the pre-scan of the program. If the pre-scan finds no ermrs in the pmgram, Start Step will change to Step, and you wilt be able to ‘step’ through the program, one statement at a time, byrepeasedly selecting Step (ermerelikely using issaccelerasorkey

In fact, you can select this optiou at any time the program is slopped. His and BASIC 2 Plus wilt go into single step mode. Si ngle Step wilt be selected in the lower part of the program menu, undone statement will be executed. When you no longer wish to single step, selecteneoftheetheroptiens(Full Speed, Debug Disabled, Debug Enabled, Show Trace - TROFF or Show Trace IRON) and then select Cxntinue, and the prograsn willcentinue in ysarchosen mode.

If you select Cnntinue withoutchoesiug one of the above options, Debug Enabled will automatically be selected for you.
28

28