Re: Weird DOS INIT bug

[dalloff@freenet.columbus.oh.us (Dave Althoff)]

Rubywand (rubywand@swbell.net) wrote:


: Dave Althoff writes ...
: > 
: > I remembered the other odd INIT thing I have noticed...
: > 
: > I seem to recall that on the unenhanced ][e (perhaps on other machines; I
: > have not had this happen in years), I have had "INIT" commands get 'stuck'.
: > 
: > Here's the dangerous situation:
: > 
: > I'm trying to format a disk on S6,D2, and something goes wrong.  The drive
: > keeps recalibrating, and clearly this INIT is going to fail.
: > 
: > I do a 3-finger salute and warmstart the machine, which boots from
: > S6,D1...a good disk.  Here's where the wierdness starts--once DOS has
: > loaded, but before the greeting program comes up, DOS immediately begins
: > to format the disk in S6,D1!
: > 
:  ....

: > It requires a very specific set of circumstances for this to happen:  you
: > must interrupt an INIT by performing a warm boot.  Stopping the INIT with
: > a RESET, cycling the power, or allowing the INIT to crash will prevent
: > problems.
: > 
: > Now...Am I nuts, or has this happened to anyone else?  8-)
:  ....

:      Hard to say. We've never owned a IIe; and, I do not recall running
: into the problem on our other II's.

:      It is surprising that a process could, at least partly, survive a
: warm boot. One possibility is that some piece of hardware, perhaps a
: Slot card, is asserting an interrupt at or just after the warm boot
: Reset. The interrupt could steer execution to some part of the INIT code
: and produce strange results.

Well, it isn't terriblly suprising considering that much of memory in the
][e is not touched during a warm boot...case in point...put a picture on
the hi-res page and see what happens to it during a warm boot:  not a
whole lot.  The trick is:  Why is it that the 'current command' gets
preserved and passed to DOS so that it executes as soon as DOS loads...and
BEFORE the usual "RUN THE LAST FILE"* or whatever normally happens.  I
would expect that the act of loading DOS would overwrite whatever command
that is, replacing it with the normal boot sequence.  I've had the
"phantom INIT" happen on more than one machine, but the last time it
happened to me was many years ago.  I do not recall whether I was using
DOS 3.3, the updated DOS 3.3, Pronto-DOS, or something else at the time.

In any case, it is an unusual occurrance, certainly nothing to worry
about.  When I stopped trying to format bad disks, I stopped having such
problems.  That's what happens when the price of a disk goes from
$7.00/each down to about $0.50/each, and my monthly income increases by a
factor of 50...  8-)

--Dave Althoff, ][.
-- 
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