Guys, thanks a lot! I've got it working!!! Thank you Benson, Skylar and 
Kirk! Now I think I need to set-up tftp server and try to install NetBSD 
on this machine... Also I might give Linux MIPS a try, although 
NetBSD/PMAX documentation seems much more consistent and up-to-date than 
docs for Linux/MIPS... Another challenge for me and my PMAX would be 
setting up Plan 9 on it, I'll be posting more on that soon.

Here I go:
KN01 V7.02

7..6..5..4..3..2..1..0

24Mb..........0

KN01 V7.02
08-00-2b-1b-bd-3e
0x01800000
>> help
CMD:

   auto
   boot [-f FILE] [-n] [ARG...]
   cat FILE...
   ctrs
   d [-(b|h|w)] ADDR VAL
   disable DEV
   dump [-(b|h|w)] [-(o|d|u|x|c|B)] RNG
   e [-(b|h|w)] ADDR
   enable DEV
   fill [-(b|h|w)] [-v VAL] RNG
   go [PC]
   help [CMD]
   ? [CMD]
   init
   passwd -(c|s|u)
   printenv [EVAR...]
   setenv EVAR STR
   test [ARG...]
   unsetenv EVAR
   warm

RNG:
   ADDR#CNT
   ADDR:ADDR
>>

Cheers,
Boris Maryshev,
The Estonian IT College,
Autonomous Robotics Lab

On Sat, 18 Sep 2004, Kirk Russell wrote:

> On Sat, 18 Sep 2004, Boris Maryshev wrote:
>
>> Hi! I made cable as described in this link and then used RS-232<->RS-232
>> console cable with it and it actually seems to work when I connect it to
>> the "printer" port, but unfortunately I don't get prompt.
>>
>> What I get is this:
>> KN01 V7.02
>>
>> 7..6..5..4..3..2..
>> ??
>> And that's all, it doesn't take any input, just prints ??, then refreshes
>> screen and loops it this way...
>>
>> Any idea what am I dealing with?
>
> http://q.dyndns.org/~blc/DS3100/bootrom.html
>
> I don't think the decstation 3100 will boot without a working ethernet
> link.
>
>
>