Subject: Re: Upgrading a 375?
To: None <Marc.Gutschner@Frankfurt.NetSurf.DE>
From: David Carrel <carrel@RedBackNetworks.com>
List: port-hp300
Date: 01/19/1999 10:24:54
> somewhere (can't remember where) I read something about upgrading a 375 to
> a 380 simply by ripping out the 'piggy-backed'(?) board with the 68030 and
> replacing it with a 68040 and inserting a new oscillator. Is it possible
> to still run NetBSD on such a 'trans-mutated' 375? And what ROM-Version do
> I need to have in the 375 to make it possible?

Marc,

this will definitely work.  I am using just such a beast right now.  But
you will need a new ROM in addition to the new 040 and oscillator.  Here
is the info you need for the ROM.

HP boot ROM for a 380
        Part #1818-5062
        Order from 800 227-8164

The oscillator should be twice the speed of the 040.  It goes in the empty
socket on the motherboard.  (When the daughterboard is installed, the
oscillator is on it.)  I run my 040 at 33MHz, but it is rated for that.
Rumor has it that you can overclock a 25MHz part to 33, but you definitely
run a risk doing so.  There is a jumper on the motherboard marked 25/33.
This seems to add a memory wait state, when set to 33.  I found that I did
not need the wait state, even when clocked to 33MHz, but if you get random
memory errors, try switching that.

Dave