From: dingebre@imp.sim.es.com (David Ingebretsen)
Subject: REPOST - A3000 Speed Improvements
Followup-To: comp.sys.amiga.misc
Keywords: spam, semprini, Bruce, naughty bits
Reply-To: dingebre@imp.sim.es.com (David Ingebretsen)
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Date: Wed, 18 Nov 1992 21:33:00 GMT


I'm re-posting the following article. Original was posted by Travis Carter.

!!!!!!!!!!!!!!!!!!!!!!!!!DISCLAIMER!!!!!!!!!!!!!!!!!!!!!!!!!!

I did this to my A3000 and it works, in fact it works great! According to
AIBB some floating operations are faster by a factor of 1.5 to 2. BUT it is
difficult at best to remove and re-solder the very fine pitched '030 and
'882. I take no responsibility if you decide to do this yourself. The '030
is the finest pitch of the two but one side of the '882 is smack up against
an edge connector. So, they both have their own challenges.

I can't help you find the parts. You will have to scrounge them yourself.

So, here is the full article:

***********BEGIN RE-POST
                         HOW TO (MAGICALLY) TRANSFORM A
                           16MHz AMIGA 3000 TO 25MHz
     ---------------------------------------------------------------------


Disclaimer:  Anyone wanting to upgrade their 16MHz Amiga to 25MHz
             is "on their own".   I, nor anybody mentioned in this
             article will be held responsible for damage inflicted on
             their (or anybody elses) machine(s) for any reason(s).  
                     
                 *********************************************
                 *** USE THIS INFORMATION AT YOUR OWN RISK ***
                 *********************************************

             Anybody wishing to upgrade using this method should be 
	     **VERY** experienced at using solder/de-soldering 
	     equipment. The 68030 CPU and 68881 FPU are *VERY HARD TO 
	     REMOVE* (!)   

             Remeber, break your Amiga, and it's YOUR FAULT, not
	     mine!!! No guarantee is suplied with this hardware hack.
	     If it doesn't work, you're on your own.  Nobody but
	     yourself can be held accountable.


Special Thanks To:  Dave Heynie.  Without him, this simply wouyldn't
		    be possible. (!)  Thank you, Thank you, Thank
		    you!!!!! 

             

Procedure:            

      (1)  First off, disconnect the power!  :)

      (2)  Remove the 68030 CPU.  This is definately *NOT* an easy
	    task! You must carfully desolder all the pins.  (The 68030
	    is packaged in a very fine-pitched 128 pin PQFP.)  Make
	    sure you remove all solder.  Don't be messy.  If you don't
	    know how to do this, don't! It is very easy to screw up
	    your motherboard.  Please make sure you know what you are
	    doing.

      (3)  Place a 25MHz 68030 CPU in the 16MHz CPU's place.  You may
	   wish to use a socket so you don't accidently damage the
	   processor.  Soldering is a lot easier than desoldering, but
	   if you don't know what you are doing, don't atempt to do
	   it.  Also, make sure you don't get an MMU-less CPU.
     
      (4)  Remove the 68881 FPU.  Do this the same as in step 2.
	   Again, make sure you know what you are doing.  The 68881
	   may not have as many pins, but it is still very difficult
	   to remove.  
     (5)  Place a 25MHz 68882 ( NOT A 68881 (!) ) FPU in the 16MHz
	  CPU's position (just like in step #3).  You may wish to use
	  a socket.  A 68882 FPU is electronically and pin compatable
	  with the 68881, except for a 50% increase in some
	  calculations.  
 
      (6)  Now you must remove the 32MHz crystal and replace it with a
	   50MHz counterpart.  (32/2 = 16MHz ; 50/2 = 25MHz) 

      (7)  Next, ITS JUMPER TIME!! (Hurray!)

               Jumper    Position   Function
               -------   ---------  ----------------------------
               J151      1-2        ROM Timing
               J152      1-2        ROM Timing
              
               J100      1-2        Quadrature Clock Phasing
               J851      2-3        RAM Controller Speed Jumper

           Please verify that these jumpers are in these positions
           before continuing.

      (8)  Verify all steps and turn on the power!


Also:          Ramsey (the DRAM controller) is designed to work with
	       80ns parts.  70ns parts will work, but don't pay
	       anymore for higher speed parts.  You won't see ANY
	       increase in speed, and there will not be an increase in
	       introduced wait states.   

               There are no different speed Agnus.  All are rated at
	       the same speed.   The same Agnus is found in the 16MHz
	       Amiga as well as the 25Mhz Amiga.  

Well, have fun!  

-- Travis Carter
   slbfn@cc.usu.edu

***********END RE-POST

The speedup was significant as far as I was concerned. I do a lot of image
processing and rendering and the extra 50% or more helps on some things.

Have fun!

-- 
	David

	Disclaimer: The content of this message in no way reflects the
	            opinions of my employer, nor are my actions
		    encouraged, supported, or acknowledged by my
		    employer.