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====== Int 21H, AH=53H ======

===== Version =====

2 and higher

===== Brief =====

TRANSLATE BIOS PARAMETER BLOCK TO DRIVE PARAM BLOCK

===== Family API =====


===== Input =====

	AH = 53h
	DS:SI -> BIOS Parameter Block (see #01663)
	ES:BP -> buffer for Drive Parameter Block (see #01395 at AH=32h)
	    DBP drive byte must be set to valid drive (Windows95-OSR2)
	---Windows95---
	CX = signature 4558h ('EX') for FAT32 extended BPB/DPB (see #01664)
	DX = signature 4152h ('AR') for FAT32 extended BPB/DPB

===== Return =====

   ES:BP buffer filled

===== Notes =====

	for DOS 3.0+, the cluster at which to start searching is set to 0000h
	  and the number of free clusters is set to FFFFh (unknown)
	if the number of sectors per cluster is set to zero, MS-DOS will hang
	  at startup because it computes the internally-used shift count by
	  shifting this value right until the carry flag is set; since this
	  will never happen when the field is zero, MS-DOS hangs
	not supported by Windows NT 3.1
          
===== See also =====

 

===== Note =====

Text based on [[http://www.cs.cmu.edu/~ralf/files.html|Ralf Brown Interrupt List Release 61]]

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