Re: Weird thing happened on my 2gs rom3

["AMart79196@gmail.com" <AMart79196@gmail.com>]

On Mar 13, 4:11 pm, demp...@actrix.gen.nz (David Empson) wrote:
> AMart79...@gmail.com <AMart79...@gmail.com> wrote:
> > [...] when I hit the openapple- control-esc, I found instead of three
> > options there, there was 5 options there.
> > I always though that those options were written into the ROM and that
> > anything else that popped up there was static and would erase on a
> > reset or turning off the machine.
>
> Correct. The extra two items you are seeing are also built into the ROM
> on a ROM 3 IIgs, but they aren't supposed to be displayed unless you
> enable them.
>
> I forget their exact names, but they are debugging tools.
>
> The official way of enabling them is to use the # command in the
> monitor. They will then appear in the CDA menu until you power off the
> IIgs.
>
> I remember that a long time ago we were investigating the same problem
> on this group - for some people (notably Mitchell Spector, I think?)
> with a ROM 3 IIgs, these CDAs were always appearing, while others
> (including mine) were behaving normally.
>
> We eventually tracked it down to a bug in the ROM 3 firmware. The
> appearance of these CDAs is controlled by a RAM location somewhere in
> the $E0 or $E1 bank, and it happens that there is no code to initialize
> this location on power-up. This means that the initial content of that
> location depends on the random contents of dynamic RAM when power is
> applied.
>
> It seems that for most ROM 3s, this location starts up containing zero,
> which disables the debugging CDAs, but some others consistently come up
> with a nonzero value, which enables them. In some others it might be
> random.
>
> Try doing a search through Google's archives for the old thread for more
> details. I think it predates my saved copies of my own posts.
>
> --
> David Empson
> demp...@actrix.gen.nz

WOW, I never knew that...buy funny that it disappeared when i pulled
the battery, and hasen't reappeared again...
I will do a search on google and see what i dig up.
If anyone else finds anything or knows anything else, please post info
or a link.  Thanks so much guys!!  Very much appreciated!