Re: ZIPGS 2-pin Crystal

[andrew.webber2@btinternet.com (Andrew Webber)]

Wayne Stewart <waynes@intergate.ca> wrote in message news:<3D13DC98.71215BAF@intergate.ca>...
> Andrew Webber wrote:
>  
> > Thanks for that. I actually have 2 ZIPGS so I decided to physically
> > take out the other bank of 32K to use in my 2nd card (only the first
> > two slots are filled). When I take the 2nd bank the card is not stable
> > at all and will not even boot GS/OS. So putting 64K cache in and
> > setting to 32K makes the system stable. Any ideas why that is the
> > case?
> 
> The main theory revolved around the second bank being a lot further 
> from the processor than the first bank and with those skinny leads.
> 
> The cheap sockets Zip used didn't help either. I originally did my 
> upgrading by soldering a half socket in the middle of the original 
> socket. Later I started wondering about the contact so I removed the 
> half sockets and replaced them with machined pin sockets. The two
> ZipGS I tried it on were previously stable at 14.5 mhz but not 15.
> After I was able to run them at 15mhz. Not spectacular but maybe 
> indicative of something.
> 
> 	Wayne


Thanks for that, but what I still don't understand is how having the
Cache in the 2nd bank but not being used makes the card stable. The
dip switches are set to 32K, but there is 64K cache installed. The
card is completely unusable with the 2nd bank taken out (still 32K
installed).

Andrew