Programmer's Workbench Information

All programs must have a .ASM extension

Options

• Each time you start PWB, do the following
  • Click the Options menu
  • Select the Build Options choice
  • Select Use Debug Options. If you don't do this, it won't build. See note below for other possibility.
• All programs must have a .ASM extension. You must type the extension when saving the file.

Note: It is possible to create an executable by using the release options. When you create a file using the Release Options you won't be able to see any symbolic information when you debug the program: ie, you won't see the names of labels or data. This is good for a release version, so that people can't see how you coded the program. It is bad when you are trying to get the program to work. For your class projects always use the Debug Options. But if you ever develop some software that you want to distribute, but don't want people to see the source, then link the program using Release Options like this:

• Click the Options menu
• Select the Link Options choice
• Check the Release Options box
• Click Additional Release Options
• Be sure that Pack Executable File is not checked.

CodeView Debugging Information

Breakpoint (F9)

A breakpoint is a line in your program that will pause execution. Whenever the program reaches this line, the execution will stop, so that you can examine variables and issue more commands to the debugger.

Step (F8)

With the step command, you can execute one instruction at a time. If the instruction is a call to a subroutine or an interrupt, then the entire subroutine is executed.

Trace (F10)

The trace command is similar to the step command, except that if the instruction is a call to a subroutine or an interrupt, then control will be sent to the first instruction inside the subroutine.

Output Window (F4)

See the output of your program.

Window Menu

There are many different windows that you can display. They are all listed under the window menu.

Watch Window

When there is a variable that you want to monitor, you add the variable to your watch window. Then, you can see the value of the variable, and see the value everytime it changes.

Register Window

The register window is very helpful. With it, you can see all the registers in the 8088. Whenever an instruction changes a value in a register, the new value will be highlighted in reverse video.

Memory Window

You can set the memory window to look either at your data segment or your stack segment. Follow these steps:

• Step through the first few commands of your program so that the DS register has the correct value.
• From the Window menu, select either Memory 1 or Memory 2.
• From the Options menu, select the same memory window as above.
• To select the data segment, enter the address expression DS:0
• To select the stack segment, enter the address expression SS:SP. Remember that the stack grows from high memory to low memory, so yo will have to scroll the window up in order to see the stack.