Call Parameters
  Standard Interface Enhanced Interface
Function Number Must be 23
Data String Preallocated string; see the following table
Length 6 or 7 implied 16
PS Position NA

The calling data string contains these elements:
Byte Definition
Standard Enhanced  
1 1 One of the following values:
  • A 1-character presentation space short name (PSID)
  • A blank or null indicating a request for the host-connected host presentation space
2–4 Reserved.
2 5 One of the following values:
  • The character B asking for notification of both host presentation space and OIA updates.
  • The character O asking for notification of only OIA updates.
  • The character P asking for notification of only host presentation space updates.
  • The character A requesting the asynchronous mode of the notification When A is specified, position 9–12 returns the address of an event object. The event selection character B, O, or P must be placed in position 13.
  • The character M requesting the asynchronous message mode of the notification.

    When M is specified, the event selection character B, O, or P must be placed in position 13 (7 for 16-bit).

  • E The character E asking for notification of completion during a printer session.
6–8 Reserved.
3–4 9–12 When M is specified in position 5 (2 for 16-bit), the window handle of the window that receives the message should be set. The message is a return value of RegisterWindowMessage (PCSHLL) (not equal 0).
7 13 One of the following values if position 5 (2 for 16-bit) is A or M:
  • The character B asking for notification of both host presentation space and OIA updates
  • The character O asking for notification of only OIA updates
  • The character P asking for notification of only host presentation update.
14–16 Reserved.