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                         MegACHIP 2000/500 REVIEW
  William Near                           

HARDWARE:  MegACHIP 2000/500 board

                                  P.O. Box 438
                                  Wixom, Michigan  48393-0438

                                  (810) 348-3821 - Sales 
                                  (810) 348-3755 - Tech
                                  (810) 348-3531 - Fax 

DESCRIPTION:  Allow 2 MB of CHIP RAM to your A500/2000/CDTV

                 313 Henderson Drive
                 Sharon Hill, PA  19079
                 (800) 93-AMIGA (orders)
                 (610) 586-5701 (info)
                 (610) 586-5706 (fax)

PRICE: I paid $195 U.S., this includes $5 S&H


SYSTEM TESTED ON: Amiga 2000 (Rev 4.4), ECS chip set, GForce '030
                  accelerator @ 50 MHz., 1 meg CHIP + 6 megs FAST memory,
                  2 standard floppy drives, Quantum LPS270S hard drive
                  with Trumpcard Professional controller, Workbench 3.1

PACKAGING: The box contained the MegACHIP 2000/500 board and a 13 page

FEATURES (according to the manual):
* Doubles the amount of RAM accessible to the custom chips
* Fully compatible with the Video Toaster - Toaster Paint and Lightwave
* Fully autoconfig, uses config space that is reserved for use as CHIP RAM
* Lets you upgrade your Amiga to stay current with the latest technology
* Fully compatible with Workbench 2.x and the ECS Denise chip
* Lets your system multitask much easier with graphic intensive programs
* Fully compatible with the MultiStart II ROM board

INSTALLATION: This is what I did with my A2000 to install the MegACHIP
board.  The A500/CDTV procedures will be slightly different. 

You must begin by removing the keyboard, mouse, and all other peripherals
from the computer.  Next, remove the case and power supply/disk drive bay.
The old Agnus chip must be removed from the socket on the motherboard
before the MegACHIP can be installed in its place.  In the past, I have
had about a 50% success ratio in removing old Agnus chips with the cheap
tool provided by Grapevine - you really should use a professional quality
PLCC chip puller.  I took my machine to a computer store and had the
technician remove the Agnus chip for me.  It only cost $10 and it saved a
major headache if the socket had been ruined in the home removal process.
Years ago, when I removed my original OCS Agnus to replace it with the Fat
Agnus (1 MB), the chip was in the socket quite firmly (mostly the dust
over the years had "welded" it in place) and some of the contacts on the
socket were messed up after using the cheap chip puller.  It cost $60 to
have a new socket placed on the motherboard!  I learned my lesson the hard
way, so consider yourself forewarned.

After the Agnus chip has been removed, and if you had only 512k CHIP RAM,
you must either change two jumper settings or one jumper and one solder
connection depending on the revision of your motherboard.  If you already
had 1 MB of CHIP RAM then no changes need to be made.

The manual states that you must hold the MegACHIP board in a certain
orientation in relation to the motherboard, but I found this to be
incorrect.  The socket adapter on the bottom of the board can only go in
the Agnus socket one way, so if you pay attention then you'll have no
problems with this step.

Now you must connect a spring action clip to either pin 36 of the Gary
chip or pin 48 of the 68000 chip.  I used the 68000 chip's pin because I
already had another clip attached to my Gary chip (a MultiStart II Board)
and I didn't want to hassle with two clips on one chip.

Finally, reassemble your Amiga and you're ready to go!

OTHER STUFF: The MegACHIP comes with 1 megabyte of memory on board which
acts as the second megabyte of CHIP RAM.  The 13 page manual is concise
and easy to follow.  It also includes a single page of trouble shooting
which covers the most common problems when trying to install the board. 
The only trouble I had when installing the board was when I first tried to
boot the computer for a test.  The computer would not boot the first time
I turned it on, so I checked the clip's connection on the 68000 chip and
re-seated the MegACHIP in the Agnus socket.  After doing these two steps
the computer booted normally.  I now have approximately 1.8 MB of CHIP
RAM, after booting, on my system versus the 780k which I had previously. 
One note to A500 owners, the MegACHIP will NOT work if you have a RAM
expansion board installed in the trapdoor that takes more than 512k of
RAM.  You should use an A501-type RAM expander in the trapdoor and use
another RAM expansion board for your other FAST RAM.

SUMMARY: The MegACHIP board is easy to install, with the hardest part
being the safe removal of your old Agnus chip.  The added CHIP memory
allows you to run more applications at once and is a big help in the DTP
and DTV areas.  If you take into consideration the price of the 8375 Agnus
chip and the 1 MB of RAM that are included on the MegACHIP board, it's a
pretty good deal.