Re: IIgs locking up after 15-20mins, TWGS likely overheating.

["ict@ccess" <gids.rs@sasktel.net>]

> > Sorry Michael!  I am jinxing your voodoo and raising you a fact.
>
> There's always some fact that causes people to believe in voodoo.  ;-)

You can fool some of the people some of the time with voodoo and you
can fool some of the people all of the time with facts but you can't
fool all of the people all of the time with (somebody else fill in
this word) --- bulls**t -- ice cream --- candy ---
>
> In this case, the "voodoo" is the notion that the bigger wires will
> increase the voltage or current delivered to the main board to a
> significant degree--and that isn't so.  There are other effects,
> though, as noted below...
>
Not at all.  My first reading of the reasons for installing bigger
wires were, bigger wires have less resistance, which reduces heat and
noise, which in turn allows for less voltage drop which means that the
power supply is sufficient to supply most slot cards which in turn
creates a more stable system.
>
> I'd be willing to bet that your crashes would also stop if you
> connected a high-value capacitor between +5v and ground in the
> vicinity of slot 7.

Don't know.  If I would have read an explanation of how that prevented
crashes instead of reading how the increased wire size reduced crashes
and made the system more stable, I might have tried that instead.
>
> Big wire doesn't do a lot to increase DC voltage, but it does
> decrease the resistance and inductance between the main board and
> the big electrolytics in the power supply.  As a result, it is
> causing the high-frequency noise to be attenuated at the bus,
> improving noise margins.
>
Finally, we agree on something  :)

> A better way to bypass the main board is to put capacitors right
> on the main board, as near as possible to where rapidly changing
> loads occur--the Zip GS and RAM card are good candidates.  (This
> is why well-designed cards have sufficient bypassing on the card.)
>
> It sounds like your system is running on the "ragged edge" of
> reliability, since a solid system shouldn't crash in weeks!  This
> makes it very sensitive to very minor changes in the noise, voltage,
> and temperature environment.  This is exactly the environment in
> which changing almost anything can make a difference.
>
Define solid system.  My system is solid if I replace the 8 MB serius
card with the 1.5 MB Apple RAM card.  Which tends to lead me to
believe there is nothing wrong with the ZipGS card, or maybe the
serius RAM card just doesn't like Zip.  And also don't forget, I went
from 10-12 crashes down to 1 with increased wire size.  Which lends me
to believe that the motherboard still can't quite handle 2 or more
large cards.

So if a system is solid with minimum cards, does that make it running
on the "ragged edge" if too many cards draw too much power and makes
it unstable?  Everything has its breaking point.

> But a digital computer is designed so that you can change all sorts
> of things by +/-10% and *nothing changes* in the functioning of the
> machine.  That's the whole point of a digital machine--that small
> "analog" perturbations are irrelevant to its operation, since it
> has sufficient timing and noise margins to not respond to them.
>
> Life is much better when you "back it off a little" and improve system
> reliability by a huge factor.
>
Is it not easier to improve or make the slot cards more efficient with
less draw on the system than trying to improve the system itself?
Modifying the motherboard is probably more than most of us care to
do.  The system has already proven to be solid with no cards plugged
in.  But such is the imperfect world.

> > I haven't soldered a wire to slot 5 ground yet though because, just
> > call me plain lazy, but one crash a day is acceptable to me.  :)
>
> Wow.  To me, that's like saying my tires are fine because I only have
> one blowout a day.  ;-)  You shouldn't have *any* crashes, except
> possibly those due to software bugs.
>
I actually have tires that have been patched 3 times and still going
strong.  :)  But the blow outs are no fault of the vehicle or the
contents of the vehicle.  They are more a cause of the load that is
being placed on the vehicle.  (How's that for an analogy  :)

> > Even 1 mVolt goes a long way to make the IIGS more stable and the
> > power supply strong enough for most purposes.  I have even installed a
> > Version 01 motherboard into a PC tower and adapted a 200 watt power
> > supply to work with the IIGS motherboard with no better results.  I
> > still crash about once per day.
> >
> > my 2 cents worth (solder and #12 gage wire extra)
>
> Millivolt variations in supply voltage are completely irrelevant to
> a stable system.
>
Again with the stable system  :)
you are not trying hard enough to break it  :)
half the fun is testing the limits

> You have at least one serious hardware instability
> in yours, and I'd bet that its the ZipGS.

Could still be possible, but ZipGS is way more stable with a 1.5 MB
RAM card than the 8 MB Serius RAM card.  I can leave the computer on
for a week without crashing.  But I really want to use my 8 MB RAM
card.  Testing with the ZipGS turned off is not really an option which
makes GSOS excruciatingly slow.

> Many overclockers just keep increasing the frequency until it crashes,
> then back off one notch.  A year later, margins have decreased to the
> point where it is now crashing at the lower frequency.  Degrading
> capacitors and power supplies, or increased loads (more cards) are
> the usual mechanism for decreasing margins.  Better to fix them than
> to "learn to live with them."
>
I believe fixing them requires new technology with lower power draw
demands.  Like, my serius RAM card would probably have lower power
consumption if I had the 1x 1MB chips instead of the 8x 1MB and thus
be more stable.  And the CFFA drives have almost no write errors
compared to the Focus Drive, but not just because of the lack of
mechanical parts, but also partly due to the less power draw.  Fixing
the motherboard is not really an option.

> If you look inside most power supplies, there's an adjustment for the
> +5v level.  Measure the +5v at the main board and adjust the pot for
> 5v (or even 5.1v).
>
Done that too.  But I am still not going to let the "benefits of
thicker wires" go.

I have done most of what has been suggested with the exception of the
capacitor to ground mod but to date, the wire mod has been the most
successful.

None of this really matters as the Bernie emulator on a beige G3 has
become my favorite computer to program on.  No problems of crashing
there.  But like most, I like to return to the original to play the
odd game.

Still only giving my 2 cents worth but if there is a reply to this
post, then I will have to increase to 5 cents due to inflation :)

Rob