[followup throughout text]

> From: Alexander Jolk <jolk@ap-pc513b.physik.uni-karlsruhe.de>
> Subject: Sun 3/60 and XKernel trouble: dies with exception
> 
> Hi,
> 

  [snip]

> (a) I installed the XKernel package from ftp.de.netbsd.org,
> /pub/unix/systems/BSD/NetBSD/arch/sun3/x11r6/Xkernel-root.tar.gz, and
> unpacked it on the Linux server under /usr/local/Xkernel-root.  I had
> /etc/bootparams point to that directory as root, and to a
> (nonexistent) file in that directory as swap.  Could this be the
> cause?  How do I have to set up that swap file?
> 
     No, though with only 4MB of ram you will probably need swap
  space.  Do the 3/60's have any internal disks, or do you plan on
  booting and swapping across the net?  XKernel is supposed to run
  swapless, but with 4MB of ram I think you can forget that idea.
  IIRC, you should make a file of n size kilobytes (depending on how
  much swap you want) if you wish to support netswapping.  use dd to
  create a file like so:

  dd if=/dev/zero of=swapfile bs=1024 count=filesize_in_kilobytes

  /dev/null ought to work for an input file as well... 

     BTW: I've never installed netbsd diskless, so I don't know what
  to do about installing the miniroot on netswap space... could
  someone elaborate on this?

> (b) I linked /tftpboot/<some hex string> to
> /usr/local/XKernel-root/netbsd, and this is what got booted by tftp as
> I can tell from the file size.  Is this correct?

     This is how I normally do it.

> 
> (c) The Sun3's arrived at our place without memory.  I installed 4
> 1MBx3 SIMMs and set the jumpers accordingly.  I know that 4MB is too
> short to do something reasonable with that machine ones it boots.
> Is the XKernel supposed to boot correctly with only 4MB, or could this
> be the cause?  (Finding more memory, or finding 1MBx9 SIMMs, could be
> difficult these days...)  I do not believe in faulty memory, though,
> because the error code seems reproducible to me.
> 

     This _is_ your problem.  Junk those 1x3 simms and go buy yourself
  real 1x9 simm boards.  I've had _nothing_ but trouble using those
  chips... an excellent explanation for why can be had in the Sun
  Hardware Reference FAQ.  See: http://www.ixa.net/~nikm/sparc.html

QUOTE:

17) My Sun doesn't like 3-chip SIMMs.

        From John O'Connor:

        3-chip SIMMs have two 4Mbit chips (organised as 1M * 4bits)
        plus one 1Mbit chip as opposed to the nine 1Mbit chips on the
        9-chip SIMMS. The difference arises from the fact that the
        4Mbit chips require more addresses to be read in the refresh
        cycles, so you get unreliable operation of 3-chip SIMMs in
        systems that don't provide enough refresh cycles.

UNQUOTE


> (d) One of the two Sun 3/60 I tested had a graphics board installed.
> I removed that for testing, but the monitor would not show anything so
> I booted using a serial console and the DIAG mode.  Is this in error?
> The other Sun3, without any previously installed graphics board,
> exhibits the exact same error, though.

     Don't have enough information to help here.  Can you tell us if
  these are bw2 or cg3/4 video cards?  Do they support color?  What
  kind of monitor do you have connected?  IIRC DIAG simply _forces_
  the 3/60 to use the serial port as a console.  One can still tell
  the boot prom to use the serial port as the console anyway.  I
  suggest you determine if the machine is configured to boot to a
  serial console before junking the frame buffer as DOA.  The FB may
  still be dead if it doesn't work on two machines, however.

Good Luck,
--jmg