Call Parameters
  Standard Interface Enhanced Interface
Function Number Must be 127
Data String See the following table
Length 8, 10, or 14 Must be 20
PS Position NA

The calling data string can contain:
Byte Definition
Standard Enhanced
1 1 A 1-character presentation space short name (PSID).
2–4 Reserved.
2 5 S or A or M
S =
Synchronous. Control is not returned to the application until the read is satisfied.
A =
Asynchronous. Control is returned immediately to the application, can wait for the event object.
M =
Asynchronous. Control is returned immediately to the application, can wait for the message.
6 Reserved.
3–4 7–8 2-byte destination/origin ID.
5–8 9–12 4-byte address of the buffer from which the data is to be written. The buffer must be obtained using the Allocate Communications Buffer (123) function.
9–10 13–16 Reserved.
11–12 17–20 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).
13–14 The data in these positions is ignored by EHLLAPI However, no error is caused if the migrating program has data in these positions. This data is accepted to provide compatibility with migrating applications.