POST Probes -> Was -> Re: Here's a plan

[James Oakley]

Matthew Sullivan wrote:

> Whilst this is a good idea, it wasn't quite what i was thinking about, for
> the only reason ... wouldn't this give us flashing problems, or can you
> also arrange to be able to flash to the '2nd' BIOS ..? (I said I was not
> much good with digital electronics design ;-))

Does anybody know how, electrically, the flash is erased and
reprogrammed? None of my books with BIOS stuff in them mention this. Is
it a MEMW or an IOW line? Either way, if you remove the BIOS and place
two of them on an appropriate ISA card with a switch on their enable
pins, it should be fine (just be careful of the switch position before
doing any flashing, of course).

> However, assuming that one BIOS can be programmed, and the other maybe
> read-only?

Simple, don't tie whatever line it is (MEMW/IOW) that enables writes to
the flash to the backup bios. And clearly label which socket is which on
the silk screen :-)


> any design ideas/plans etc...  If this works, I'd like to get my
> hands on a plan ASAP cause this would be just what I need...

Once a list of features is finalised, it's probably a matter of a couple
of hours to design the schematic and board (I have an autorouter at
work, we've done PCI boards before). Then we can figure how much one of
these babies will cost us each (most expensive is the board itself,
though there are some cheap solutions out there now, such as ExpressPCB
(~US$100 for a couple of boards, most of which is the setup fee,
additional boards cost much less)).

We also could etch the boards ourselves, but that way lies madness. It
sounds cheap at first but you don't want to try to draw an edgecard
connector with a marker (Rat Shack style), and not everyobody has access
to a UV oven or a CNC machine. 


> If you're carful you could even make a business plan & money from it... but
> more on that when we see what we've got....

Nah, no market for that outside of people like us, I prefer the
non-profit approach anyway (why do you think I hang around here?). I
propose that any additional electronic design be part of the OpenBIOS
project, like what is done by many Linux packages that have specific
hardware.


Is anybody else interested? Speak now... please :-)


James Oakley
jfunk at roadrunner.nf.net