INT 21 - DIET v1.43e - SET ADDRESS OF EXTERNAL PROCEDURE                        
	AX = 37DCh
	BX = 899Dh ('DI' + 'ET')
	DS:DX -> external procedure (see #01397)
Return: AX = 0000h
Note:	the resident code will call the specified external procedure at the
	  beginning of decompression and when compression is exited on failure
SeeAlso: AX=37DDh


(Table 01397)
Values DIET external procedure is called with:
	STACK:	WORD	class
			FFFDh creation failed for unknown reasons
			FFFEh creation failed due to lack of space
			FFFFh file creation error
			else file handle of DIETed file to be decompressed
		DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	-> compressed filename
		DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	-> decompressed or temporary filename
Return: SI,DI,BP,DS,ES must be preserved by external procedure