Int 21 Fn 2511  P - Phar Lap 386/dos-extender - Issue Real-mode Interrupt  [E]

   AX = 2511h
   DS:EDX -> parameter block (see below)

Return: all segment registers unchanged
   EDX unchanged
   all other registers contain values set by the real-mode int handler
   the flags are set as they were left by the real-mode interrupt handler
   real-mode register values are returned in the parameter block

Note:  this function is also supported by FlashTek X-32VM

See Also: AX=2503h,AX=2505h,AX=250Eh,AH=E3h"OS/286",INT 31/AX=0300h

Format of parameter block:
Offset Size    Description
 00h   WORD    interrupt number
 02h   WORD    real-mode DS value
 04h   WORD    real-mode ES value
 06h   WORD    real-mode FS value
 08h   WORD    real-mode GS value
 0Ah   DWORD   real-mode EAX value
 0Eh   DWORD   real-mode EDX value

Note: all other real-mode values set from protected-mode registers