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

[marvinmiller@hotmail.com (Marvin Miller)]

Hi Rubywand,

Thanks for the info! 

About the ZipGs running stock - tried that, I think it wants to go
faster than 7Mhz. Myself, I was hoping for 15 at least.

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.

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

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. (I figure it'll be a
while before they show up)

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. I checked the downloadable
sections of the catalog by couldn't find a p004. I'm lost, as you can
probably tell.

Lastly, where can I get a single new WDC proc?

Thanks very much for your help, I appreciate it!
Marvin Miller

On Sat, 11 Nov 2000 18:08:09 -0600, Rubywand <rubywand@swbell.net>
wrote:

>Marvin Miller writes ...
>> 
>> Hi Folks;
>> 
>> I'm trying to assemble a lit of the items & part numbers of components
>> needed to upgrade my Zip GSx 1.02.
>> 
>> I've read the FAQ's and searched the newsgroups to obtain all info
>> regarded to this process and I still have some questions.
>> 
>> ** Replacing the 74F00 chip with the 74HC00 one **
>
>     Where did you find this in the FAQs?
>
>
>> 
>> I have found that it's a 14 pin DIP. Doing a search on Digikey and
>> narrowing it down to one manufacturer (FairChild) and Package to
>> 14-DIP still brings up a numerous possibilities.
>> 
>> The 74HC00 questions seem to arise out of the IC Function and Number
>> of Circuits variables. Can anyone help to isolate the _exact_ one I
>> need?
>> 
>> Some of the possibilities IC Functions are;
>> 
>> 2 Input NAND Gate, Inverter, 2 input AND Gate, Buffer, Inverting
>> Schmitt Trigger, 8-bit Shift Register, 2 Input OR Gate, D Type Flip
>> Flop, 2 Input Exclusive OR Gate, 2 Input NOR Gate, Binary Counter (4
>> bit), Bilateral Switch etc.
>> 
>> Some of the possibilities on Number of Circuits can be;
>> 
>> Quad, Hex, Octal, Dual etc.
>>
>
>     The 74F00 and 74HC00 are variants of the old 7400-- the IC has four
>2-input NAND gates.
>
>     Do not know why anyone would replace a 74F00 with a 74HC00 on an
>accelerator board. The 74F00 is a much faster gate than the 74HC00. You would
>think that when speeding up a board you would, if anything, want to move to
>faster gates. Suggest you leave your 74F00 where it is until whoever made the
>recommendation explains it.
>
>
> 
>> *** Going from .600 --> .300 on the Cache Chips ***
>> 
>> It looks like I've found what I needed here. From the DigiKey catalog
>> what's needed is (4) A504-ND Goes from .600 --> .300 using 28 Pin DIPS
>> 
>> *** Oscillators ***
>> 
>> Listings from DigiKey show both;
>> CMOS TTL Full Size &
>> Full Size
>> 
>> Are these interchangeable? IE: Does the CMOS spec make it different?
>
>     If the pin spacing for each is standard "full size", the clock modules
>should be interchangeable for your application. The oscillators on page 144
>of catalog P004 (CTS Reeves MX045) look pretty good. You want a "standard
>output" model.
>
>     It's a good idea to get two or three different frequencies-- like 36MHz
>for 9MHz operation, 40MHz for 10MHz, 48MHz for 12MHz, ... . This lets you
>experiment with operation at different speeds.
>
>
>> 
>> Once I get through this and have the right parts, I'll post a part
>> number list for all the items needed from DigiKey and whathaveyou, so
>> someone can just order the stuff without doing this leg work. I
>> couldn't find the ness. info in the FAQ's. To me it seems you still
>> have to have a pretty decent underestanding of electronics to make iot
>> from the the FAQ to ordering.
>> 
> ....
>
>     Guess that's true for something like an accelerator upgrade project. 
>
>     By the way, (don't recall if you mentioned this) have you tried out your
>accelerator 'as is'?  
>
>     Something else: be sure to check out the power supply lead and
>motherboard mods discussed in the Power Supply and Cooling FAQs at ...
>
>http://home.swbell.net/rubywand/Csa2POWER.html#007 .
>
>
>
>Rubywand