Is 440BX ported to Linuxbios v2?

Richard Smith smithbone at gmail.com
Thu Jan 13 13:49:01 CET 2005


> > http://www.digikey.com is your friend.
> >
> > Well really almost any JDEC part 2MBits and larger will work.  If you
> > use a larger part you might have to ground the unused address lines if
> > they left them floating on the pcb.
> 
> Thanks for the links. No luck with any of the links given, however. How
> to find a replacement part?

They are there but you just don't know what to look for. *grin*  First
off you part number is incorrect it should be W29C020 not W290C020. 
But there are't that many people who sell windbond.  But you don need
a windbond any 2MBit part will work as long as the footprint is the
same... any 29?020 part will work.

Oh wait a minute... I bet you don't have a programmer do you?  Ick. 
In that case foget what I said.  You will need a part supported by the
hot swap trick.

Ron.  What flash parts are supported by your hotswap trick?
 
> I know about the 100MHz rating for 440BX. However, on the board you can
> select 66/100 MHz FSB and the BIOS supports the higher FSB speeds. Also
> the board has multiplier settings (3-5) x (66,100) MHz = 200-500 MHz for
> CPUs with changable clock multipliers. The board runs today with dual
> Celeron (Mendocino, 300MHz, before Intel disabled dual on Celerons) at
> 103/66*300MHz = 466MHz stably for many years now.

The mutipler settings cannot be set by software.  The P6 samples
several pins on the transition from Active RESET to inactive RESET to
determine its multiplier.  The driver of those pins must tri-state
after the sample because they are used for other things.  At this
stage BIOS code hasn't even been started.

So that means that there is a small microcontroller (or some other
hardware) that is configureable and will see that those straps are set
correctly at de-assertion of reset.

This will be difficult to figure out.  If you are lucky the chip
responsible for this is on the smbus and you could reverse engineer
the commands.  But in any case it would be a lot of work.
 
However this may also mean that once they are set they will never
change.  So you might be able to put in the BIOS that came with the
board.  Set your settings and then use LinuxBIOS after that.

-- 
Richard A. Smith



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