Category: <b>disk I/O enhancements</b>
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<pre><b>INT 21 - Advanced SCSI Programming Interface (ASPI) - INTERFACE</b>

	AX = 4402h
	BX = file handle for device "SCSIMGR$"
	CX = 0004h or 0005h (refer to notes below)
	DS:DX -&gt; buffer for result (see <a href=../../it/52/14.html>#01452</a>), set to zeros before call
Return: CF clear if successful
	    AX = 0004h or 0005h (refer to notes below)
	CF set on error
	    AX = error code (01h,05h,06h,0Dh) (see <a href=../../it/80/16.html>#01680</a> at AH=59h/BX=0000h)
Notes:	the variant of the call requesting five bytes is an UNDOCUMENTED
	  extension supported by Adaptec's ASPI2DOS.SYS, ASPI4DOS.SYS, and
	  ASPI7DOS.SYS; if made of a host manager which does not support the
	  variant, only four bytes will be returned.  If the variant is
	  supported, Adaptec's WINASPI.DLL assumes that the host manager is
	  an "advanced" one which operates in either real or protected mode
	  (and thus does not require a DPMI INT 31/AX=0301h call to be invoked
	  from protected mode).	 Support of the five-byte variant also appears
	  to imply that an advanced ASPI host manager uses no temporary
	  storage space except the SRB (see <a href=../../it/54/14.html>#01454</a>) and the stack, and that it
	  is fully reentrant.
	if called with a standard request for four bytes, even Adaptec's
	  advanced drivers return only the requested four bytes containing the
	  ASPI entry point address
	the function address is called with the address of a SCSI Request
	  Block (see <a href=../../it/54/14.html>#01454</a>) on the stack and the caller must clean up the
	  stack
SeeAlso: AX=440Ch"ASPITAPE",INT 11/AH=FFh"WD7000"

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