INT 21 P - Phar Lap 386/DOS-Extender - LOAD FLAT MODEL .EXP or .REX FILE
        AX = 2529h
        ???
Return: ES:EBX -> parameter block
        ???
Note:   details not available at this time
SeeAlso: AX=252Ah

Format of parameter block:
Offset  Size    Description
 00h    DWORD   initial EIP
 04h    WORD    initial CS
 06h    DWORD   initial ESP
 0Ah    WORD    initial SS
 0Ch  4 WORDs   initial DS, ES, FS, GS
 14h    DWORD   minimum size in bytes of program segment
 18h    DWORD   bytes of additional memory allocated
 1Ch    DWORD   flags
                bit 0: child linked with -UNPRIVILEGED
                ---v6.0+ ---
                bit 1: child is PE file instead of .EXP
                bit 2: loaded file is a DLL
                bits 3-31 reserved
---v6.0+ ---
 20h    DWORD   module handles (PE files only)
 24h  7 DWORDs  reserved (0)

.