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/// Usenet Review: Two Meg Agnus Project
By Hamish Tweedie
The Two Meg Agnus Project. Version 5.0d3 22-Sep-1993.
A user-installed kit which allows Amiga 500 and 2000 computers to
have 2 megabytes of Chip RAM by using an updated Agnus chip. It is
user-installed, and optionally may be ordered preassembled.
Information is available on all Aminet ftp sites in the file
Name: Structured Applications and Designs Inc.
Address: P.O. Box 60414
San Diego, CA 92166
The board may be purchased in a number configurations. (Note all
prices are given in US dollars.)
Board fully ASSEMBLED, with RAM: $88.95
Board fully ASSEMBLED, with NO RAM: $64.95
Board NON-ASSEMBLED, with PARTS and with RAM: $79.95
Board NON-ASSEMBLED, with PARTS but with NO RAM: $54.95
Board NON-ASSEMBLED, with NO PARTS and NO RAM, (Bare
printed circuit board): $50.95
In addition, you may purchase the following options:
2 meg Agnus chip, part number #318069-03: $35.00
PLCC Agnus extractor tool: $ 4.95
Piece(s) of insulator: $ 0.95 each
68000 socket extender: $ 4.95
As you can see, a fully assembled board can be purchased for $128.90
-- main board ($88.95), Agnus chip ($35.00), and Agnus extractor tool
($4.95) -- which is markedly cheaper than the prices I have seen advertised
in AmigaWorld Magazine (approximately $196.50 (US)). Furthermore, you get to
support Amiga PD developers :-). I purchased the NON-ASSEMBLED version with
parts and RAM option for $79.95, plus the Agnus chip and the extractor tool,
costing $119.90 in total (plus postage).
SPECIAL HARDWARE AND SOFTWARE REQUIREMENTS
This project will work on all Amiga 500's, and all late
model Amiga 2000/2500's. This means that any Amiga 2000
which has the older Amiga 1000 DIP-style Agnus will not work
(i.e., those Amiga 2000's produced in Germany).
It will not work on an Amiga 600, 1000, 1200, 3000, 4000 or
If you have an Amiga 500, you'll require an extra 512K RAM
in the belly slot to expand memory. If you intend to
install the project in an Amiga 2000, then you should already
have 1MB installed on the motherboard; and even if you
currently have only 512K set as Chip RAM, instructions are
included for the conversion.
The following hardware is required for the conversion:
1: If the kit is already assembled, then you require only
the $4.95 PLCC chip extractor tool (definite requirement)
plus the 2MB Agnus chip.
2: If you purchased a non-assembled kit, the following is
required to complete the installation:
- Any parts listed under "LIST PRICE", above, that
were not supplied with the kit.
- PLCC chip extractor tool.
- soldering iron.
- flat blade screw driver (useful).
- X-Acto or similar knife.
- magnifying glass (optional, but very useful).
- multimeter (optional).
- tin snips.
I presume it works with all faster CPU's. Mine is currently
very happy running with a GVP 22Mhz 68030 Combo accelerator
board. Note that if you have a board which covers the Agnus
socket you may have problems, and should consult the
documentation in the archive, or the authors.
MACHINE USED FOR TESTING
- Amiga 2000.
- Initially, 1MB Chip RAM and 7MB Fast RAM.
- Tested on Kickstart 37.175 (2.04) and Workbench 38.12. Also booted
up in Kickstart/Workbench 1.3 and everything appears OK (not fully
- Running GVP 22Mhz 68030 Combo board. Works fine with hard drives
attached to the SCSI bus. Set up has 2MB 16bit Fast RAM (A2058
board) and 5MB 32bit RAM (Combo board). GoldenGate II board also
running with two extra PC serial lines. CBM deinterlacer. All
- All software that I ran appears compatible.
[MODERATOR'S NOTE: If you are not comfortable opening up your
Amiga, then you should have the work done by an authorized Amiga
service center. Careless work may damage the computer. - Dan]
The old Agnus has to be removed (and for this, the PLCC chip
extractor is an absolute requirement). The new board is then inserted into
the motherboard socket left vacant by the Agnus chip, and a wire lead is
attached to a pin on the 68000 (I used the 68000 attachment, even while
running an 030) or the Gary chip. That's it!
The installation was dead easy, and the only worry was static
discharge from myself (I didn't use a static mat or strap... slap on wrist!
The project assembly was much easier than I had suspected. The
board is well laid out with everything clearly marked, and thus is of good
quality. All boards come with the PLCC plug soldered to the board, due to
the difficulty of this operation.
The assembly in its basic form consists of the following (note that
this only applies to the kitset boards):
1) Solder PLCC socket to the PCB. Not difficult, but it requires a
little care and accuracy.
2) Solder in the three SIP resistor packs. Very easy.
3) Solder in the nine capacitors into the board. Very easy.
4) Solder the clip lead to the board (already assembled on kitset
boards). Very easy.
5) Solder the eight RAM chips to the PCB. This was a little harder
as I was worried about static and overheating the chips, and so it
required a bit of precision and a speedy hand on the soldering iron.
6) Solder the 24-pin PAL chip to the PCB. Same skill level as above.
7) Install the 2 Meg Agnus chip into the socket on the board. Pretty
8) Install, as mentioned above in previous section.
This process took me about an evening to complete (say 7:00pm to
1:00am... yes I was enjoying myself that much :-)). But the work could
easily be split up over multiple periods, as recommended in the
documentation, to ensure that a high standard of work is achieved. Mine
turned out pretty fair. The soldering wasn't production line quality, but
is reasonably respectable. I found it easier to solder the pins on chips,
sockets, etc., after they had been bent a few degrees (note I was *very*
careful doing this!).
Note that none of the above applies to the complete, fully
assembled project, which arrives the same as the commercial products (with
the exception of the higher price tag).
Overall, I obtained a great deal of enjoyment. This was the second
board I have soldered (the first being the Multi-Kickstart, also produced by
Structured Applications and Designs), and found it much easier to complete
than the previous one. Basically, if you can plug a soldering iron in, and
handle it with a small degree of proficiency combined with a desire to
produce work of a decent standard, you shouldn't have much hassle assembling
the project. The instructions are a breeze to work through and provide a
step-by-step assembly and instruction method which is easily understood,
even by somebody as electronically inept as I am!
Overall if you're not going to upgrade to a new Amiga, yet require
or would like 2MB of Chip RAM, then this is the cheapest path to achieving
your goal. Don't be scared by the skill required to assemble the project or
the time taken to assemble it, as both are negligible.
How useful is the extra 1MB of Chip RAM? Well now I can multitask a
lot better, running numerous windows and doing a number of tasks that
previously I could not do (e.g., read my news with Grn, while downloading
with JRComm, while viewing IFF's). It has turned me into a bit of a slob
though, as I tend to leave more windows open. :-) It also aids those of us
that *have* to use MagicWB.
This consists of the assembly, installation and compatibility files
that accompany the Public Domain archive on Aminet. These ASCII files are
also accompanied by a number of IFF pictures which aid the assembly and
provide complete schematics for the project (i.e., PCB layouts, etc).
The documents are superb, and provide a step by step description of
both the assembly and installation process which are easy to follow. There
are even IFF pictures of parts which may be hard to identify for the
beginner (e.g., capacitors, chips, etc).
Also included in the documents is an order form and description of
how the project works and the theory behind it.
LIKES AND DISLIKES
I believe that the project is brilliant! It provides a cheap way to
upgrade your Chip RAM while introducing the beginner to a project which
provides a great deal of satisfaction and builds confidence (is this a good
thing with static sensitive electronics ;-)).
I have no complaints about the quality of materials involved, the
documentation, nor the implementation of the whole project.
COMPARISON TO OTHER SIMILAR PRODUCTS
The project is a Public Domain implementation of similar commercial
products available, such as the DKB MegaChip product. I haven't used or heard
any complaints about the commercial products.
I had to contact the authors, Neil Coito and Michael Cianflone,
several times via email concerning a delivery date. Both times they were
helpful and courteous. The problem was that new circuit boards were being
produced and delays had occurred. The product arrived (after a delay in
Customs) at approximately the time specified by the authors.
Both authors offer themselves in the documentation as available for
consultation if any problems are encountered. Once the board arrived I had
no problems nor need to consult.
I am not affiliated with the company in any way except as a
There appears to be no warranty. It is mentioned in the documents,
that if a part is defective, then contact Structured Applications for help,
and I presume replacement parts are free of cost. All the boards are sent
out fully tested, apparently.
I consider the project brilliant, and hope that further projects of
this type appear for/from the Amiga community. It is well executed in terms
of both documentation and hardware. It achieves its aims, and appears to be
at least on a par with commercial products.
If forced to give a rating, at this stage I would give it 4 out of
5. The remaining star depends upon the long term reliability of the
product, which at this stage I have few doubts about. If it stays as
reliable as it currently is, then I would happily recommend 5 out of 5!
Copyright 1993 Hamish Tweedie. All rights reserved.
Reprinted with permission.