Re: Overclocking a stock Apple IIgs?

[supertimer@aol.com (Supertimer)]

m.kelsey@spam.eecs.wsu.edu wrote:

>Does anyone know the implications of overclocking a stock Apple IIgs
>in the same manner as a ZIP chip for the Apple //e?  It can be handled

In the SAME manner as a ZIP chip IIe?  Sure.  It is called the ZipGS.
There is also a competing product called the Transwarp GS.

>very easily with modern PC's, however, support must exist on the mother-
>board.  With the IIgs I realize that the hardware onboard isn't capable
>or guaranteed to operate properly above the stock conditions.  If a

The problem is that the video and I/O are tied to the same clock as
the CPU.  Thus, trying to change the motherboard clock will screw
up the video and I/O.

The ZipGS and TransWarp GS lets those other things operate
normally but increases the CPU clock (the CPU is moved to
a slot card).  Speeds up to 16Mhz are possible!

>person were able produce a do-it-yourself kit, I wonder how much actual
>work would be required.  Other concerns would center around 5.25" disk

After installing ZipGS/Transwarp GS, changing speed requires
swapping an oscillator (which clocks the CPU).

>access, bus speed for 8-bit cards, ROM access time, the internal clock,
>mainboard memory, and the audio chip (Ensoniq).

The logic in the ZipGS/Transwarp GS takes care of this.

>May somebody has already published a method for overclocking a stock
>Apple IIgs, pending a faster CPU (e.g. 20Mhz or 14Mhz) could be located?

14Mhz is already here.  Commodore users have 20Mhz.  The info is
in the FAQs on Ground.  ;-)

My Transwarp powered GS is at 12.5Mhz (windows pop open and
slam shut as fast as my Win95 unit)!