From: Sonny Hung (sonnyhung_at_gmail.com)
Date: Thu Oct 21 2004 - 06:56:49 PDT
On Thu, 21 Oct 2004 05:52:16 -0700, Humphreys, David
<david.humphreys_at_honeywell.com> wrote:
> The base clock provides the cadence for the whole system. Switching crystal
> freqencies on the fly requires waiting for the next clock cycle before that
> action. If you switch at the wrong time there will be an incomplete clock
> cycle and all manner of problems can arise.
> They can range from a total reset to more subtle problems like an incomplete
> write to memory. So, just because you may not have seen a problem doesn't
> mean it isn't waiting in the wings.
David,
Thank you very much for chiming in on this topic. Your words of wisdom
and clear expalination which warns those like myself who consider
attempting this. I believe one of my conversations with Ronnie went
over the need at times for downshifting on certain apps that have a
problem with the higher speed so I was aware of this.
Anyone STILL interested in a (Raw GearShift) upgrade can contact me as
I have the ability to only install a handful (four more maybe) and as
warned clearly you do this at your own riskknowing the inherent
problems associated with this procedure.
> I have a solution for this. It is called 'Gearshift'. I have mentioned this
> before. I have designed a circuit that has NO CRYSTAL and switches
> glitchlessly (is that a word??) between normal and accelerated speeds.
> Furthermore, it requires no user intervention. What this means is that the
> Newton will run at accelerated speed until a function that requires normal
> speed is invoked. It then throttles down until that function is completed
> and switches back to turbo. Nice ehh? The benefits of an accelerated Newton
> WITH serial port compatibility.
Being that I have only signed up in the last year to NTLK - I had not
hear of 'Grearshift' and ask if you have any idea what the financial
setback would be if it were a seperate option or included in a Neton
mega board you mention below?
> Now this is concept and prototype at the moment but it works thus far and I
> just have to make a decision whether to make it stand alone or incorporate
> it into a 'Newton mega board' incorporating other goodies.
What other goodies are being considered for inclusion in this Newton mega board?
> Sonny, as far as the crystals go I will save you some time and tell you that
> 5MHz is the limit. Any faster and the memory will act flakey.
Thanks for the heads up - this Complete Post I believe should go into
the WikiWikiNewt! under OverClocking/GearShifting or something in that
line...
-- God bless, Sonny Hung the Hung Family -- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries Official Newton FAQ: http://www.chuma.org/newton/faq/ WikiWikiNewt for all kinds of articles: http://tools.unna.org/wikiwikinewt/
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