Re: ZipGSx Upgrade Problem??

[Rubywand <rubywand@my-deja.com>]

In article <3a1a23f8.1563461949@news>,
  marvinmiller@hotmail.com writes ...
> Hi RubyWand;
>
> The sockets are in the proper location. The card actually has some
> silkscreening to show where the sockets should be and this works with
> either .3 or .6. Also, in your faq it mentioned just cutting out
> sections and putting in sections. Extrapolating on these  two sources
> - they're in the right place.
>
> As for oscillator, it's the stock one for 7 MHz proc speed. I didn't
> want to change anything else at the start, and the card does work, but
> only with the DIP set for 32k cache. I checked the soldering on the
> back of the second bank of chips (obviously first bank works as it
> runs at the original 32k) and they all look 100% As I mentioned, the
> job went great and I was very confident of the work (I have zip for
> soldering skills but it looks good :-)
>
> Is it right to have 4 of the same SRAM's, or did I need to buy two of
> one type and two of another? All I did was get 4 identical SRAM's with
> two being a slower rating. Correct?
>
> Also, is the order correct? This is from left to right as viewed head
> on
> ;
> TAG 15ns DATA 20ns TAG 15ns DATA 20ns
>
> If that's all correct, I'd have to say I have either;
>
> - A bad chip
> - Bad soldering
 ....



     To eliminate worries about bad IC's, checking that the other two
RAM chips work in the first two sockets in 32k mode seems like a good
idea.

     Clicking the RAM size DIP switches back and forth a couple times
before setting may help.

     Incomplete RAM socket connections is a possibility. If a pin is
lightly soldered to the eyelet on the solder side, you may not have a
connection to a trace on the other side. Adding a little new solder and
sweating each new connection a bit could be a fix. (This is done with
the RAM chips removed.)


     Your selection and arrangement of RAM chips sounds okay. Our
10MHz/64k ZipGSx came from Zip Technology with four '6206 45ns RAM IC's.
At 7MHz, it may not matter which of your very speedy SRAMs is in Tag and
which is in Data.


     You mention that you are still running at 7MHz; but, you do not say
what other new stuff is present. For instance, if your new 65C816 is
plugged in, then the 74HC00 should probably be plugged in, too.

     Tests with the new 65C816 and the 74HC00 in place in 32k mode at
7MHz and higher speeds should be interesting. Once you are running at
around 10MHz, try a test in 64k mode. (Not sure what effect using such
fast RAM may have on 64k mode operation-- you may find that 64k mode
works better at higher speeds.)




Rubywand


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