INT 31 - CauseWay - "GetDOSTrans" - GET DOS TRANSFER BUFFER

	AX = FF25h
Return: BX = real-mode segment of transfer buffer
	ECX = transfer buffer size
	DX = protected-mode selector for transfer buffer
Note:	the default buffer size of 8K is sufficient for most applications,
	  but an application performing large amounts of file I/O may benefit
	  from allocating its own, larger buffer
SeeAlso: AX=FF00h,AX=FF26h