Re: 4400/200: (1) update, (2) "RESETing to change Configuration!"?

[David Riley <fraveydank%gmail.com@localhost>]

On Sep 25, 2021, at 10:45 AM, Mouse <mouse%Rodents-Montreal.ORG@localhost> wrote:
> 
> (2)
> 
> There's another symptom, though, which has shown up recently.
> 
> Sometimes - usually in response to a reset-all or boot command - it
> will print
> 
> RESETing to change Configuration!
> 
> give a startup chime (a second one, if in response to a reset-all), and
> drop into its flashing-question-mark mode.  (A few times, I've managed
> to press cmd-opt-O-F in time and get directly into OF, but usually I've
> had to power-cycle to do that.)
> 
> When it does this, it not only does the flashing question mark thing,
> it also resets real-base to -1.  It does not reset load-base.
> 
> Any idea what's behind this, what I can do about it, etc?

This is the expected consequence of losing PRAM battery power (same as losing battery power in any other machine that keeps config parameters in SRAM, like PCs, Suns, etc)... it's detecting a corruption of the parameters due to the power loss and resetting to defaults.

The solution to this, of course, is to get a battery in there (people do make replacements for that weird Rayovac 3-cell monstrosity, because it was fairly popular, but the 3-AA replacement was pretty common back in the day).  The expected effect is about the same as if you held down cmd-opt-P-R at boot, which intentionally resets the PRAM.

No idea why it doesn't reset load-base, unless the load-base is something that's the same as the default?  Or possibly it's a part of the PRAM that doesn't get erased by the reset routine, in which case you should treat it as suspect because it could well be corrupt at that point.

Note that replacing the battery will probably also help with point (1) (trimmed), as a lot of that is likely due to a power management component locking up due to brownout.  A LOT of Macs from the 68k era up through late PPC did not deal well with bad battery power.


- Dave