Format of Phar Lap real-mode call parameter block:
Offset	Size	Description	)
 00h	WORD	real-mode DS value
 02h	WORD	real-mode ES value
 04h	WORD	real-mode FS value
 06h	WORD	real-mode GS value
 08h	DWORD	real-mode EAX value
 0Ch	DWORD	real-mode EBX value
 10h	DWORD	real-mode ECX value
 14h	DWORD	real-mode EDX value