Zip GSX - Extra Components

[Polymorph]

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

[Drew]

Hmmm i have a Zip GSX 1.0.1 that i doesn't have any logic chips on but
i had the sockets fitted and when putting the chips on the system
wouldnt boot. I wonder if i am missing some components for the ICs to
work...as i don't have the caps or resisters near the Logic chip
sockets...I have the transistor though

Drew

[Hugh Hood]

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...@v15g2000prn.googlegroups.com, Polymorph
at polym...@hotmail.com wrote on 11/18/09 4:19 AM:

[Polymorph]

On Nov 19, 1:17 am, Hugh Hood <hughh...@earthlink.net> wrote:
> 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
>

Thanks for the info Hugh! Your explanation makes sense.

So I'm guessing people (like myself) who have a newer 65816 do not
need these extra components? I'm wondering if you try and push the
14MHz 65816 past 14MHz whether this mod would be beneficial?

Cheers,
Mike