The primary option menu is displayed after TSO (Time Sharing Option) has established your session. It appears as a series of numbered options, each representing a different function or service provided by ISPF. For example, option 2 typically represents the EDIT function, which invokes the ISPF editor. The screen layout includes a prompt for "Option ===>", followed by a list of available functions.

To access any of the displayed functions, you need to enter the corresponding option number at the bottom of the screen next to the "Option ===>" prompt and press the Enter key. This action selects the desired function or service from the menu.

Each option in the ISPF Primary Option Menu leads to a specific function or panel, which can be defined using either a set of panel definition keywords or HTML-like tags. The most common functions include:

These panels are used to display a list of processing options that users can choose from. An example is the Primary Option Menu itself, where you can select different functions by entering their respective option numbers and pressing Enter.

For data entry tasks, such as inputting information required for specific applications, these panels provide fields where users can enter necessary data. This data is then processed by the application to perform its intended function.

These panels are used to show some or all of the information contained in a table. They are particularly useful for displaying and manipulating data stored in tables, which is common in database applications and other structured data handling tasks.

The ISPF interface includes command tables that list commands and their corresponding actions. Users can enter these commands by typing the command name at the appropriate prompt on the screen. For example, you might see prompts like "Enter command:".