[rescue] Re: ultra 1 with weird errors

Gavin Hubbard ghub005 at xtra.co.nz
Wed Aug 6 06:08:24 CDT 2003

>Message: 5
>Date: Sun, 20 Jul 2003 23:53:01 +0200
>From: Frank Van Damme <frank.vandamme at student.kuleuven.ac.be>
>Subject: [rescue] ultra 1 with weird errors
>To: rescue at sunhelp.org
>Message-ID: <200307202353.02156.frank.vandamme at student.kuleuven.ac.be>
>Content-Type: text/plain; charset="iso-8859-15"
>Hello list,
>I have found a dutchman with an ultra 1 that he's willing to sell -
>unfortunately the machine gives an error on boot-up, in the openboot prom.
>"Fast Data Access MMU Miss"
>Now, I'm not familiar with this, but what does it mean and most importantly:
>is it repairable? What parts may need replacing?
>Frank Van Damme    http://www.openstandaarden.be

Hi Frank

By coincidence, I picked up an Ultra 170e this afternoon that had this
exact same problem. It would get to OBP fine but whenever I tried to boot
it from disk or CD it gave the "Fast Data Access MMU Miss" error.

I turned the diag-switch on and the diag-level to max and this showed that
someone had loaded the memory in the wrong order. In this particular system
there was 64MB in banks 1,2, and 3 while bank 0 was empty.

Interestingly the system was detecting all of the memory (192MB) at startup
and appeared otherwise quite normal (no warning messages about misloaded
memory) and it was only at boot-up that it failed. Rearranging the memory
so it occupied bank 0,1, and 2 immediately fixed the problem.

I'm not saying that this is neccesarily the fault with the system you are
looking at, but it is definitely worth checking out as a possibility.

Best regards,


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