> To: Herb Peyerl <Herb.Peyerl@sidney.novatel.ca>
> Cc: port-hp300@sun-lamp.cs.berkeley.edu
> Subject: Re: 040 support. 
> Date: Tue, 14 Jun 1994 17:33:11 -0700
> From: David Carrel <carrel@cisco.com>
> 
> I already tried this.  No go.  I popped out the "L shaped" daughter board
> and put in a 040.  You must also add a 50MHz oscillator to run the 040 at
> 25MHz.  (When the daughter board is in, it has a 100MHz oscillator on it.
> Without the daughterboard you must add add an oscillator on the motherboard
> right next to the 040 socket.)  With the 040 and oscillator, my system
> fails in the rom diagnostic test.  The diagnostic LEDs say that the error
> is "can't find alpha video".  That doesn't mean much to me but I figured
> that it was a 040/030 incompatibility.  (Addressing???)  I tried two
> different 040s.  One is known to work.
> 
There are a variety of CPU registers and memory mapped HW locations that
the ROM prods to attempt to identify the CPU.  It sounds like it thinks you
have an old hp200.  It probably doesn't match any of the hp300 profiles so
it guesses you are the only other thing it knows about, a 200!

> Yes the jumper marked 25/33 is for running the 040 at 25 or 33 MHz with a
> 50 or 66 MHz oscillator.)  Somebody at HP once told me that it "should"
> work at 33.
> 
So you are saying that a 380 could be upgraded from a 25mhz 040 to a 33mhz
one with the proper crystal?  Might have to try that with our main server
machine (it has 3 SCSI controllers, 3 HP-IB controllers and 3 LAN cards so
we cannot just move all its peripherals to our hp433 box due to lack of DIO
slots).

> So...  Does anyone know how to access the ROM.  Is it mapped into memory?
> If I had a ROM burner and a program that would let me read ROM contents
> from a live system ...
> 
This is most likely illegal.  We asked HP if we could make copies of a newer
ROM set for SCSI boot support for our 320s but they said no and the idea was
dropped (since we didn't want to pay $200 bucks a pop for 20+ sets of ROMs
for obsolete machines!)  We just use our slowly diminishing supply of HP-IB
disks on these machines...

Anyway, the ROM is mapped into the physical memory address space starting at
the low 64k or so I believe.  There is a test in hp300/mem.c which prevents
/dev/mem accesses from going outside of RAM.  If you disable that, you should
be able to see the ROM contents.  The ROM uses the first page of physical RAM
as scratch space (which BSD never touches).

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