Int 21 Fn E1  - Os/286, Os/386 - Issue Real Procedure Call                 [E]

   AH = E1h
   ???

Return: ???

Note:  protected mode only???

See Also: AH=E0h"OS/286",AH=E2h"OS/286",AH=E3h"OS/286",AX=250Eh,INT 31/AX=0301h