I've got 3 VAXstation 3100s that I'm playing around with.

===== vax1 =====

KA42-A  V1.3          

>>> b/100
Bootfile: NETTEST
-ESA0
OpenBSD/vax netboot test
Cpu Type  : a (CVAX)
Board Type: a000004 (VAXstation 3100 model 10-48)
Sie Data  : 4010002                              
Boot Dev  : 99 (LANCE)
Booted from ESA0      
Ethernet  : 8:0:2b:12:92:40 7800
(Q)uit) : 

>>> show ver
42-A  V1.1BD-16F-V4.6-24C
        PST: 16F         
        CON: 1BD         
        VMB: V4.6        
        ROM: 24C         

>>> show dev
 VMS/VMB  ULTRIX    ADDR    DEVTYP  NUMBYTES  RM/FX  WP  DEVNAM  REV
 -------  ------  --------  ------  --------  -----  --  ------  ---
 ESA0     SE0     08-00-2B-12-92-40
 DKA300   RZ3     A/3/0/00  DISK      209 MB   FX        RZ24   211B
 ...HostID....    A/7       INITR                                   
 ...HostID....    B/7       INITR
                                 
>>> show mem
        01800000         
        00000000         
        017E1800:017FFFFF

===== vax2 =====

KA42-A  V1.3          

>>> b/100
Bootfile: NETTEST
-ESA0
OpenBSD/vax netboot test
Cpu Type  : a (CVAX)
Board Type: a000004 (VAXstation 3100 model 10-48)
Sie Data  : 4010002                              
Boot Dev  : 99 (LANCE)
Booted from ESA0      
Ethernet  : 8:0:2b:d:78:89 7800
(Q)uit) : 

>>> show ver
KA42-A  V1.1BD-16F-V4.6-24C
        PST: 16F         
        CON: 1BD         
        VMB: V4.6        
        ROM: 24C         

>>> show dev
 VMS/VMB  ULTRIX    ADDR    DEVTYP  NUMBYTES  RM/FX  WP  DEVNAM  REV
 -------  ------  --------  ------  --------  -----  --  ------  ---
 ESA0     SE0     08-00-2B-0D-78-89
 DKA300   RZ3     A/3/0/00  DISK      209 MB   FX        RZ24   211B
 ...HostID....    A/7       INITR                                   
 ...HostID....    B/7       INITR

>>> show mem
        01800000         
        00000000         
        017E1800:017FFFFF

===== vax3 =====

KA42-A  V1.3          

>>> b/100
Bootfile: NETTEST
-ESA0
OpenBSD/vax netboot test
Cpu Type  : a (CVAX)
Board Type: a000004 (VAXstation 3100 model 10-48)
Sie Data  : 4010002                              
Boot Dev  : 99 (LANCE)
Booted from ESA0      
Ethernet  : 8:0:2b:15:2e:15 7800
(Q)uit) : 

>>> show ver
KA42-A  V1.1BD-16F-V4.6-24C
        PST: 16F         
        CON: 1BD         
        VMB: V4.6        
        ROM: 24C         

>>> show dev
 VMS/VMB  ULTRIX    ADDR    DEVTYP  NUMBYTES  RM/FX  WP  DEVNAM  REV
 -------  ------  --------  ------  --------  -----  --  ------  ---
 ESA0     SE0     08-00-2B-15-2E-15
 ...HostID....    A/7       INITR
 ...HostID....    B/7       INITR

>>> show mem
        01000000         
        00000000         
        00FE3E00:00FFFFFF

=====

I'm able to MOPboot all three using the stuff from ftp.luth.se.

Vax1 and vax2 fail with the following error.  I can get vax3 to single-user.

boot device: le0           
nfs_boot: using network interface 'le0'
le0: receiver disabled                 
le0: device timeout   
revarp failed, error=51
no file system for le0 
cannot mount root, error = 79
root device (default le0): le0: device timeout
le0: device timeout                           

It is also interesting to note that vax3 will boot (with a munged kernel 
ethernet address) with the mopboot and kernel @ 
ifib4.ifib.uni-karlsruhe.de:/pub/netbsd-vax but vax1 and vax2
fail with the following after MOPing the bootstrap.

device: le0 attached to 08:00:2b:xx:yy:zz
le0: transmit timeout, stat=0x13
le0: output buffer busy
...
le0: output buffer busy

The only difference I can see in the 3 machine is the amount of memory.

vax1 and vax2 have 24 megs of ram, and vax3 has 16 meg.  Would this
make a difference?

Thanks

/* 
   Matthew N. Dodd		| A memory retaining a love you had for life	
   winter@jurai.net		| As cruel as it seems nothing ever seems to
   http://www.jurai.net/~winter | go right - FLA M 3.1:53	
*/