The PISA Session

The PISA system serves to create, test, use, and maintain application software based on PISA programs. Each of these activities involves a dialogue between the user and the PISA, system. The user is either a person occupied with software production, a person interacting with application programs, or a PISA program that makes use of the PISA system to process specific tasks. Persons maintain their dialogue with the PISA system via a real terminal while programs employ a pseudo terminal. At the moment a user establishes connection to the PISA system, a PISA session is assigned to him; the PISA session provides the user with the hardware and software resources supported by the PISA system.