Format of CauseWay executable:
Offset	Size	Description	)
 00h  2 BYTEs	signature "3P"
 02h	DWORD	size of header data in bytes
 06h	DWORD	size of EXE image data in bytes
 0Ah	DWORD	number of bytes of program memory required
 0Eh	WORD	number of segment definitions (see #03165)
 10h	DWORD	number of relocation table entries
 14h	DWORD	offset of program entry point
 18h	WORD	segment list entry number for entry point's CS
 1Ah	DWORD	initial ESP
 1Eh	WORD	segment list entry number for initial SS
 20h	DWORD	control flags (see #03164)
 24h	DWORD	automatic stack size in bytes if ESP entry = 00000000h
 28h	BYTE	length of name (name follows program image)
 29h 23 BYTEs	reserved
SeeAlso: #01594,#01609 at INT 21/AH=4Bh