Re: TransWarp & Zip GS upgrades

[supertimer@aol.com (Supertimer)]

CUTblakeney@home.com (Jeff Blakeney) wrote:

>supertimer@aol.com (Supertimer) wrote:
>
>>The newer design 14Mhz 65C816 is different because
>>on the TWGS and Zip GS it is underclocked so it runs
>>very comfortably at 5v at any speed.  In fact, the design
>>has proven stable up to at least 20Mhz which is why
>>CMD can use them in the SuperCPU accelerator at
>>20Mhz all the time.  In fact, running the newer 65C816
>>at higher than normal voltages is a waste of time and
>>will put your entire IIGS at unnecessary risk.  That's
>>why I tried so hard to get Nathan to update his FAQ
>>on accelerators which recommends voltage increases.
>>At the time, Nathan ignored all requests to update the
>>FAQ.  I believe there are still folks out there who have
>>5.5v on the 14Mhz chip for no benefit at all because of
>>this.
>
>What makes you think that increasing the voltage won't help?
>
>If you are trying to push the processor and make it run faster, it
>will try to draw more power.  If it tries drawing more current than
>can be supplied then the voltage will start to decrease.  If you
>increase the voltage, then the voltage decrease will only lower the
>voltage to its normal level of 5V rather than something that might be
>too low for the processor to continue operating.
>
>This is the way electronics work.

You are correct BUT the current WDC CPU is rated at
14Mhz (with selected units rated by outside lab to
20Mhz for CMD).  Thus, on the IIGS, this chip is not
overclocked.  Therefore, it should be run on standard 5v
voltage.

Nathan's accelerator FAQ was written with a certain
assumption.  This was that a 65C816 of the older
design was used.  The older design would basically
be overclocked at the faster TWGS and ZipGS speeds
users now push their IIGS.  Using the older processor,
YES voltage increases would help.

But the 14Mhz chip is designed to run faster without
the need for a voltage boost.  So why do it and risk
your IIGS?  The way Nathan's FAQ was set up, it
recommended increasing the 5V line at the power
supply which meant that following the instructions,
the entire IIGS would be run on a 5V line increased
to 5.2V-5.5V.  That's not good.