To look at some of the CodeView commands while running HELLO.EXE, make the Source window active by pressing F6 or by clicking its title bar. Then choose the Restart command from the Run menu. Restart clears memory and prepares the program to start execution at .STARTUP.
Press F5 or choose the Go button at the bottom of the screen to start the program. The program executes until it reaches the breakpoint you set at the INVOKE directive.
If you press F8 or the Trace button, CodeView executes and displays each statement of PutStr. If you use F10 or the Step button, CodeView executes PutStr without showing each step.
The variable pMsg is actually a pointer, so no value is displayed until you execute the PutStr procedure. As you step through PutStr, the display switches to the output screen each time a character is written to the screen.
Because pMsg is also a local variable, it appears in the Local window with all variables local to PutStr. You can expand local data in the Local and Watch windows by double-clicking it.
Press F10 to finish stepping through the program. A dialog box informs you that the program has completed execution normally. Press ENTER to clear the dialog box and complete your debugging session.