Re: ZipGSx Upgrade Questions (I've read the FAQ's)

[marvinmiller@hotmail.com (Marvin Miller)]

Hi Rubywand;

Your right about me having the part number backwards. I spent most os
Sunday trying to 'cram' all the ness facts & figures together and what
do you know? If you look at something long and hard enough, a simple
thing becomes complex!

Also, thanks for the info on the oscillators. It just confirms that I
am looking at the right ones (I printed the section of the cat with
them - the very same ones you mentioned).

So, the good news is that I now know exactly what oscillators to buy,
the chip sockets for the cache and the 74HCOO mod. I think what I'm
going to do is see if the electronics shop can put a socket under that
particular chip as well. This way I have one more easily changeable
variable.

Now, on to the memory types! 

At this rate I should be able to order soon and see what I can get
from the Zip.

Thanks (I'm almost there...);
Marvin Miller

On Sun, 12 Nov 2000 19:07:41 -0600, Rubywand <rubywand@swbell.net>
wrote:

>Marvin Miller writes ...
>> 
> ....
>
>> About the ZipGs running stock - tried that, I think it wants to go
>> faster than 7Mhz. Myself, I was hoping for 15 at least.
>>
>
>     10MHz is 'fast enough' to comfortably run System 6.0.1 and practically
>all current IIgs applications. 15MHz is roughly the upper limit for reported
>ZipGS upgrades.
>
>
> 
>> About the 74F00, I couldn't find it in the FAQ but I did pull it up
>> several times through DejaNews. Here's a transcription...;
>> 
>> "I've done some other reading up and apparently ZipGS's can be pushed
>> beyond 12.5Mhz, however with some work on the end user's part.  The
>> Zip will need to have the 74F00 replaced with 74HC00, which is $.045
>> from Digikey. Also, the SRAMS will have to be changed to faster ones,
>> at least 15ns."
>> 
>> End transcription. I've seen this in a couple of places with no
>> description whatsoever about what this mod accomplishes. The general
>> consensus is that if your aiming for top speed, do the mod.
>>
>
>     Based upon Wayne's information and the info quoted from David, it looks
>like the recommendation is valid. Replacing the 74F00 with a socket (for
>plugging in the 74HC00) seems like a good idea.
>
>
>
>> Also, it's important to note that the DigiKey part number given in the
>> FAQ for the socket adapters seems to be the wrong one, being A502-ND.
>> I'm not certain, but I know in my case I need the A504-ND
>>
>
>     Think you may have it backwards. A current Digi-Key catalog shows the 
>A504-ND as an adaptor for using 28-pin 600 mil chips in 300 mil sockets. To
>use skinny 300-mil 28-pin RAM chips in 600-mil sockets, you would want the
>A502-ND.
>
>     To help avoid confusion in the future, the FAQs for Accelerators has
>been changed to be a bit more explicit about the adaptor and to refer users
>to the adaptor maker, Aries, and to the Aries part number.  
>
>
> 
>> My understanding of the motherboard power issues was that a Rom 03 had
>> most of the mods done.
>> I haven't looked at the FAQ yet as I've been
>> trying to get the parts for zip mods ordered.
>
>     FAQs information about the power mods does note that the ROM 3 is
>supposed to have better Slot area power distribution and may not require the
>motherboard mods.
>
>     The main concern would be with your power supply leads. Since you plan
>to run with an accelerator above 10MHz and plug in other boards to enhance
>your IIgs, it is likely that the leads coming from the standard IIgs power
>supply will be too skimpy (as outlined in Q&A 005 on the Power Supply and
>Cooling page http://home.swbell.net/rubywand/Csa2POWER.html#005 ).
>
>
> ....
>
>> On the oscillator front, you mentioned;
>> 
>> >The oscillators on page 144
>> >of catalog P004 (CTS Reeves MX045) look pretty good. You want a "standard
>> >output" model.
>> 
>> What catalog is this? I checked page 144 in the Digikey one (full
>> catalog, pdf format) and couldn't find it.
> ....
>
>     There may be differences between the on-line and print catalogs. Just
>look for CTS Reeves oscillators (or Digi-Key part numbers like CTX120-ND,
>...).  Oscillator selection does not appear to be critical. My reason for
>suggesting the particular brand is mainly a lower specified current
>requirement.
>
>
> ....
>
>
>
>Rubywand