doscp cannot copy 4,244,522-byte file

[ZKO3-2/S14]

	I cannot copy a file from a DOS partition to UNIX with doscp.
 
	I issue the commands
 
	    link /dev/rdsk/0s8 /dev/dos/C	;my DOS is in partition 3
	    doscp -bm C:/gnu/gnuemacs.tar /gnu
 
	The hard disk is active for about 10 seconds, then nothing 
	happens. After about 5 minutes, I reboot the machine and find 
	an output file whose size is 645,120 bytes.
 
	The source file contains 4,244,522 bytes.  (I've successfully
	copied a file of about 150,000 bytes.)
 
	I'm using System V/AT (PS/2 mod 60, i.e. 80286).
	The hard disk contains 2 partitions: DOS & UNIX.  The UNIX
	partition contains only SYSTEM V/AT, newly installed.
 
	Any thoughts on how to copy this file to the UNIX partition?
 
	Network address:	decvax!decwrl!asd!digrazia
                                            or
			    asd.dec.com!digrazia at decwrl.dec.com
 
	Regards.