Howdy,

Couldn't a guy put a 555 timer in there and have it trigger a non-
sound event every 3 or 4 minutes to keep things powered up? It could
be switched off when APO is desired.
Rig


--- In CasioSK@yahoogroups.com, "plutoniq9" <Plutonique9@...> wrote:
>
> Considering the SK-1 shares the same CPU as the SK-5 & SK-8, it
could
> most probably be fixed with a ROM hack. Problem is, of course, no
> deompiler is available for the OKI CPU used by the SK's, and the
> company have never bothered to respond to any requests I have made,
> bastards.
>
> I got to a certain point with revese engineering specific areas of
the
> SK code....I did this by f'king with specific areas of code (they
are
> seperated in ROM) and then seeing what part of the SK this would
mess
> up. I did this over and over again until I'd identified a good deal
of
> the code (envelopes, preset rhythms/melody, sample looping points
etc.)
>
> However, & a BIG however it is, bytes make little sense without a
> decompiler it's hard to get predictable results with trial and
> error.......
>
> So many projects, so little time
>
> cya
>
> ryan
>
> --- In CasioSK@yahoogroups.com, "gmeredith1" <gmeredith1@> wrote:
> >
> > I have been doing some testing and some research about this, and
> > have come to the conclusion that it is not possible to do this.
> >
> > I have sought to bypass the APO signal line from the SK's
processor
> > and connect an external 5V supply to the power circuit
transistors
> > to keep the keyboard awake. I thought that this would do it, and
now
> > the rest of the keyboard does stay powered up, but the processor
> > itself actually shuts itself down after 7 mins. The lights stay
on,
> > but nobody's home. The keyboard will not operate.
> >
> > Referring to the service manual, you can basically work out what
> > i've done. But I believe the processor itself has a timer in it
that
> > is hard-wired internally in the chip that shuts itself off, no
> > matter what else goes on in the keyboard. That's a damn shame, I
> > really thought I was on to something.
> >
> > I can pretty much assume that all other casio keyboards with the
APO
> > feature will operate in the same way. I have a Casio DG20 digital
> > guitar which I tried it on, and it does the same thing.
> >
> > There IS one way that you can work around this feature, and that
is
> > to press any button or key on the keyboard every 6 or so minutes,
> > before the APO switches off. Knowing this, it should be able to
make
> > a small timer circuit with a tiny relay or electronic switch that
is
> > hotwired to some relatively unused function button on the
keyboard,
> > that will do this automatically.
> >
> > Anyone have anything to add to this?
> >
> > Cheers, Graham
> >
>