Before your program can use ARs to reference data in an address/data space, it must establish a connection to the address/data space. The important facts to remember about setting up an environment in which your program can use ARs follows:

• Establishing addressability to an address/data space means your program must:
  • Have authority to access data in the address/data space
  • Have an access list entry that points to the address/data space
  • Have the ALET that indexes to the entry

This section describes these actions and gives some examples. The first item in the list, having authority to access data in the address/data space, depends on whether the entry is for a data space or an address space.

• Authority to add an entry for a data space follows certain rules that are summarized in Table 1. This table tells what problem state and supervisor state or PSW key 0-7 programs can do with data spaces.
• Authority to add an entry for an address space is determined by whether you require that the system check the EAX value of the program when the program issues an ALESERV ADD macro. CHKEAX=YES asks the system to make sure the program has the appropriate EAX value before executing the macro. CHKEAX=NO tells the system not to check the EAX value of the program. EAX-authority is described in EAX-authority to an address space. Only programs in supervisor state or PSW key 0 - 7 can use CHKEAX=NO. If they have EAX-authorization, problem state programs with PSW key 8 - F can add entries for address spaces to their access lists.