Re: Problems with ZipGS Upgrade

[Rubywand <rubywand@swbell.net>]

CPT FA writes ...
> 
> I followed the CSA2 FAQ on Accelerator Upgrades and tried mine.  I had a 7Mhz
> ZipGS with a soldered oscillator (28Mhz Full size).  I desoldered it and
> installed a 14 pin socket then replaced the 28Mhz with a 50Mhz oscillator (Full
> Size).  When I reinstalled the card and powered up all I got was a black and
> white checker board screen.  When I removed the card and replaced the oriningal
> CPU chip I booted up just fine at 2.8Mhz :(.  Here's my questions; have I
> ruined my board?  Is there anything I can do to fix it?  Is there anyone out
> there that can do this upgrade/repair?

     Your board is probably okay. Users have been experimenting with
speed upgrades for quite a while and lots have run into the checkerboard
screen. (A very common cause of the checkerboard screen or all-white
screen is a ZipGS making poor contact in its Slot socket.)

     You do not mention whether or not you swapped in one of the new
65C816's from WDC. A board is not likely to go from 7MHz to 12.5MHz
without the new chip.

     The new 65C816 and a 50MHz osc gives you a fair shot at 12.5MHz if
your RAM is rated at 45ns or faster. Since 12.5MHz was the upper limit
reported by John Link in his tests with 45ns RAM, it's a good idea to
have some slower osc modules-- like 40MHz, 45MHz to try out.



Rubywand