Re: Zip GSX - Extra Components

[Hugh Hood <hughhood@earthlink.net>]

Mike,

Basically, these are a  series of mods that Zip (and later, others) did in
the early days to power the CPU from the 12 volt line rather than the the 5
volt line.

Zip, by running the 12 volt line through some resistors and a voltage
regulator, knocked the voltage down to about 5.6 volts so that a 65C816
rated at 7 MHz could do 9 MHz. (at least for a while).

I've been told that the new 14 MHz (redesigned by Sanyo for WDC) CPUs don't
need the > 5 Voltage to run reliably at higher speeds, although the WDC spec
sheets show that they'll take up to 6 volts, I believe.

Hugh Hood




in article 
f943839e-75cc-4156-907f-02aa05ef8a9c@v15g2000prn.googlegroups.com, Polymorph
at polymorph69@hotmail.com wrote on 11/18/09 4:19 AM:

> Hi Guys,
> 
> I've been watching an auction on eBay for a 14MHz Zip GSX, and seeing
> the photo's with the additional components (extra capacitors,
> resistors and what looks like a transistor?) got me to wondering what
> these additional components are for.
> 
> I modded my Zip GSX a couple of years ago to run at 12.5MHz, and am
> curious as to whether these additional components are needed for
> higher speeds on a Zips GSX? If not, what are they for? Most pictures
> I've seen of the Zip GSX don't have these components installed,
> however, I have seen more than one picture with them.
> 
> Can anyone shed some light on what the additional components might be
> for? Is it recommended to add these components to a Zip GSX that
> doesn't have them? Can anyone list exactly what the additional
> components are? (The specific components I'm referring to are at C16,
> C17, C19, C21, R7, R8, & Q2).
> 
> I haven't performed the logic chip upgrade as yet (from 'F' series
> chips to 'Q' series) either - I understand that this is critical to
> hit the higher speeds. But what role does the other components play?
> 
> Thanks for any info.
> 
> Cheers,
> Mike