Function  27h  Random Block Read From File Specified by Struct -FCB
     Similar to 21h (Random Read) except allows multiple files to be read. 
entry   AH      27h 
	CX      number of records to be read 
	DS:DX	address of an opened Struct -FCB
return  AL      00h     successful read 
		01h     end of file, no data read 
		02h     DTA too small for record size specified (read canceled) 
		03h     end of file 
	CX      actual number of records read (includes partial if AL=03h) 
note 1) The record size is specified in the FCB. The service updates the Current 
	Block (offset 0Ch) and Current Record (offset 20h) fields to the next 
	record not read. 
     2) If CX contained 0 on entry, this is a NOP. 
     3) If the DTA is larger than the file, the file is padded to the requested 
	length with zeroes. 
     4) This function assumes that the FCB record size field (0Eh) is correctly 
	set. If not set by the user, the default is 128 bytes. 
     5) The record is written to disk at the current DTA address as specified  
	by the most recent call to function 1Ah. If the size of the record and 
	location of the DTA are such that a segment overflow or wraparound would 
	occur, the error return is set to AL=02h