Several uses of GDDM's simpler alphanumeric functions were discussed in "Basic procedural alphanumerics" in topic 5.0. This topic provides guidance on some of the more complex uses the alphanumerics API, such as:

• Defining multiple fields
• Querying modified fields
• Specifying default field attributes
• Using light-pen fields.

Subtopics:

• 13.1 Example: Alphanumeric menu program
• 13.2 Concepts introduced by the MENU program
• 13.3 Redefining the attributes of existing fields
• 13.4 Resetting the default value of an alphanumeric field attribute
• 13.5 Processing an alphanumeric field with changed status
• 13.6 Using procedural alphanumerics for double-byte characters
• 13.7 Performing output of strings mixing single- and double-byte characters
• 13.8 Field outlining on the IBM 5550 Multistation
• 13.9 Improving the performance of procedural alphanumerics applications