[rescue] best NetBSD support

[Greg A. Woods]

[ On Wednesday, June 19, 2002 at 11:37:09 (-0400), Steve Sandau wrote: ]
> Subject: Re: [rescue] best NetBSD support
>
> In any case, just because it was deprogrammed in place does not mean
> that it can be re-programmed in place. If the deprogramming prevents
> access to the chip, then re-programming may not be possible.
> 
> As a parallel, if you try to flash a PeeCee BIOS and it fails so badly
> that you cannot boot the machine, then you may not be able to re-flash
> the BIOS to fix it. If the BIOS were soldered in, that would ruin the
> motherboard unless you could desolder the old chip and replace it.
> 
> It seems that that could very well happen.

Like I said before, there are undoutably bad designs out there (and one
would expect more incidents of such bad design in PCs than in VAXes).

Most designs I know of though use a small EEPROM that cannot be
accidentally erased by any software means (as the required voltages are
just not ever present in-circuit), and this "safe" firmware can be
enabled with a jumper or switch to load a FlashRAM burner from floppy or
whatever.  This is the way the DEC Multia works, and similarly some of
the flash-able Intel motherboards I've looked at.

Chuck McManis already has a "good" image of the FlashRAM for the
4000/90:

    http://www.mcmanis.com/chuck/computers/vaxen/resources/4k90firm.bin

One person reports that the FlashRAM is configured to be written to by
default (which kinda makes sense given the way they use it), so perhaps
just writing the image to the correct locations is all that's required.

In any case given the relatively good experiences others have reported
with their VAX 4000/90 models, this rare, and perhaps now erradicated,
problem seems silly to worry over, even if you are a VMS nutcase who
might have a momentary lapse of insanity and desire to try NetBSD.  :-)

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods at acm.org>;  <g.a.woods at ieee.org>;  <woods at robohack.ca>
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