I failed in netbooting NetBSD-1.4.1 from Slackware 4.0.
There was no response when I typed in:
	>> boot 3/tftp

---- DECsystem 5000/260 hardware infomation ----
>> cnfg
(1)	 (2)						(3)
3: 	KN05		DEC	V2.1k	TCF0	(32MB)
						(enet: 08-00-2b-39-c5-2f)
						(SCSI=7)
1:	PMAG-DA		DEC	V5.3g	TCF0	(PMAGB-EA: PXG+---D=24)

>> cnfg 3
3:      KN05            DEC     V2.1k   TCF0    (32MB)
--------------------------------------------------------
DEV	PID			VID	REV	SCSI DEV
========================================================
rz0	RZ58	(c)DEC		DEC	2000	DIR
rz1	RX23	(c)DEC		DEC	0054	DIR
rz4	CD-ROM	XM-3401TA	TOSHIBA	0283	DIR
tz5						SEQ

cache: I(16KB), D(16KB), S(1024KB), Scache line(32 bytes)
processor revision(4.0)
mem(0): a0000000:a1ffffff(32MB)
---- DECsystem 5000/260 hardware infomation ----

Please help me find the reason.
Some information:

---- /etc/bootptab ----
.default:\
        :hn:\
        :ds=202.38.64.1:\
        :sa=202.38.72.161:\
        :gw=202.38.72.190:\
        :sm=255.255.255.128:

dec:\
        :tc=.default:\
        :ht=ethernet:\
        :ha=08002b39c52f:\
        :ip=202.38.72.164:\
        :hd=/tftpboot:\
        :bf=install:\
        :rp=/usr/local/root/NetBSD
---- /etc/bootptab ----
---- /etc/exports ----
/home/ftp/pub/NetBSD-1.4.1/binary/sets	dec(ro, no_root_squash)
---- /etc/exports ----

/tftpboot/install is gunzipped from 
	.../binary/kernel/install.gz
Files in /usr/local/root/NetBSD are extracted from 
	.../installation/netboot/diskimage.tgz

/usr/sbin/rpc.mountd and rpc.nfsd have been restarted.
So has /usr/sbin/inetd.

install.ecoff also met the same problem.

TIA,
yours
	Sonnie Hook