Function  3Fh   Read From A File Or Device 
		Read from file with handle  

entry   AH      3Fh 
	BX      file handle 
	CX      number of bytes to read 
	DS:DX   address of buffer 

return  flag CF 0       successful read 
		1       error 
	AX      0       pointer was already at end of file 
			or number of bytes read 
			or error code (5, 6) 

note 1) This function attempts to transfer the number of bytes specified in CX 
	to a buffer location. It is not guaranteed that all bytes will be read. 
	If AX 
     2) If performed from STDIN (file handle 0000), the input can be redirected 
     3) If used to read the keyboard, it will only read to the first CR 
     4) The file pointer is incremented to the last byte read. 
     5) The data is read beginning at the current file position.

bugs:	Novell NETX.EXE v3.26 and 3.31 do not set CF if the read fails due to
	  a record lock (see AH=5Ch), though it does return AX=0005h; this
	  has been documented by Novell
Attempting to read close to 64k of data in one chunk MAY result in data corruption 
near the end of the block when running under Window 98.