#Installing 1Mb Agnus
42 messages in this thread
Has anyone tried installing their own 1Mb Agnus chip? I'm just wondering
how difficult it is and what paths and pitfalls there are. I'm getting
close to doing a memory upgrade on my 2000, and I want the larger chip
space.
As Always, Paul
I just ordered the 1meg CHIP Agnus (Super Fat Agnus) for my A500, and plan
on taking the adventure tonite (It arrived today) and install it! Wish me
luck! I'll report back here with my results.
Joe, I certainly hope you have the special tool that is needed for removing
the old Agnus. A number of people have cracked the socket trying to get it
out with a screwdriver, and then they had a REAL problem. Best wishes in
your adventure – you're much braver than I am. (And I'm not afraid to
insert chips, either)
……Betty
Betty,
Thanks for your concern. I had ordered the chip from The Grapevine group
(they advertise in Amiga World) due to the fact that they include the chip
extractor for no charge. ($99.95 for the Chip + free extractor).
I wouldn't dare attempt to remove it with a screwdriver.
I successfully installed the Fatter Agnus last night, and now have a
whopping 1 meg of Chip memory available for my use. The installation was
simple, and took only 7 minutes to complete. I was informed by my local
dealer that it was a tough job, and to let them perform the task instead –
but I insisted otherwise.
Pulling the chip out was simple. It requires some dexterity, and I can see
how one may damage the socket. The modifications were simple, two traces
need to be cut, and one trace needs to be soldered.
Anyhow, it works, and I'm happy!
Joe
JOe, I am glad you were successful, and that all went well. I believe that
having that special tool makes all the difference. I've not heard of
people having problems if they had that tool – but there was much grief
when the new Agnus first became available and people were trying to do the
job without it!
Congratulations!
……Betty
Joe:
That extractor tool, does it appear like a U-shaped piece of spring
steel, bent inward and filed down at each end? I, too, ordered my chip
from GrapeVine and got no extractor. Another letter, and this "thing"
came. What I got is an ordinary IC puller than someone filed down with a
Dremel. Is that all there is?
Regards Tom
Tom,
The "tool" looks identical to a standard chip puller, though with the edges
filed down to fit inside the "slots" in the Agnus chip holder that allows
the tool to grab ahold of the chip. If you "dremel"ed a normal chip puller
to the point of fitting in that slot , and having the end bent to grab onto
the chip it shoudl work fine. Take care though, the chip is usually stuck
in there pretty good (at least mine was) and may take a bit of prying to
get it out. Don't use brute force!!! This will definatley destroy the
motherboard. If you damage the chip holder, the entire motherboard needs to
be replaced. (At least, that's according to my local dealer).
If ya have any questions, let me know! The mod took under 10 mins to do,
and is real simple if you are familiar with the insides of your computer.
Joe
Joe,
The correct tool hooks under the chip (by the slots) and then the
tool itself presses down on the carrier and thus pulls the chip straight
out of the socket. While you can certainly get the chip out by lots of
other methods…including a sanded down normal chip puller…it is not the
recommended method.
The important point is that the chip must come straight up out of
the carrier, otherwise it can very easily bend the contacts in the carrier
and/or the chip and/or break the carrier.
Don
Thanks for the information. When I ordered the Fatter Agnus from Grapevine
they included what they call a Fatter Agnus chip extractor. This extractor
looked like a sanded down normal chip extractor – nothing special. The ends
fit perfectly into the slots, and grabs under neath the chip. It allowed me
to pull upwards on the chip to pull it out of its socket. Though not fool
proof, it worked fairly easily.
The tool you mention, sounds like a different critter than what I used.
Joe,
Yes, the tool I was talking about is different. The problem with
the tool you got with the chip is that it can cause problems. I'm glad you
didn't have any.
The carrier/chip are designed so that the chip is supposed to pull
straight out of the carrier, and be pushed straight into it. Also, it's a
rather tight fit…so can take a bit of effort to pull it you. If you pull
on the chip, without pushing on the socket at the same time, it is possible
to harm the carrier and/or motherboard. The proper tool pushes on the
carrier as it pulls on the chip…so there's no force on the motherboard.
Anyway…the tool you got, worked for you, and apparently works for
others. I just thought I'd throw in a comment on the differences.
Don
Don,
Thanks for your concern. The chip extractor I used was awkward, and I'm
sure the one you mention would be easier to use, and of course more
expensive.
When I used my tool, I made extra caution as not to harm my motherboard.
(The last think I need is a new motherboard). When I pulled on the chip
(with a straight upward motion, not a sideways type pulling action) I made
sure I held down the socket with my other hand – trying not to allow the
motherboard to bend upwards. Though, I'm sure that others without the
know-how or experience will use the extractor as they would w/ a 64-pin
chip, and use it to "rocker" the chip out so to speak.. that would be
disasterous!
Don,
If you have a Newark catalog, take a look at page 698 to see what AMP
Special Industries calls an extraction tool for removing chip carriers from
chip carrier sockets. It is very close in operation to the puller supplied
by GrapeVine, but they charge a whole ot more for this one!
73, Kelly
Kelly,
No, I don't have access to a Newark catalog. The one I've got is
sold thru Jameco and was about $13.00. It looks like a small wishbone
inside a larger wishbone (if that makes sense). The center of the small
wishbone is attached to a bar that runs thru the center of both (actually,
it's attached to both also) and it ends in a round plate that sits ontop of
the chip.
The small wishbone fits in the PLCC socket and has "hooks" to go
under the chip. The large wishbone has pads that fit against the socket so
they can push on it. By squeezing on the outside or large wishbone, you
end up with a "push on the socket while you pull on the chip" type action.
I hope that all made some kind of sense to you. Anyway, it all
works well…no problem at all, and very easy to use.
Don
Tell me about it, Don. I had one guy bring his A2000 in to the store after
he had tried the "gluing the nut on top of the Agnus" trick. When he
screwed in the bolt and gave a big pull with the Vise Grips, the whole
socket ripped out of the motherboard, dangling traces and all. OUCH!
Greg
Greg White / MicroSearch 72230,1617
We listen to our customers..carefully
A big pull with VISE GRIPS! Boy, this guy must be into self-torture.
Greg:
VICE GRIPS!!!??? Hee-hee. What did him in was the monstrous vacuum
that was created by the sudden departure of the large, square chip from its
cozy nest. 😎 I'm surprised he was "man" enough to bring it in for
repairs, let alone admit what he had done. Of course, maybe what he
*really* did was to PC-7 the chip to the socket or the motherboard. 😎
That would be funny, too. PC-7 is the stuff used to schmutz the golf ball
to the side of a Coca-Cola bottle that you saw sticking around hardware
stores and the like, challenging you to part them. Some guy did, one day,
at the Reading Boat Works, only a large chunk of the bottle remained with
the ball. 😎 Pretty good epoxy, I must say.
Regards Tom
The tool is NOT a simple piece of U shaped metal. The proper tool pulls the
Agnus up, and distributes the force across the socket. Using the tools you
described or the nut and bolt method puts stress on the PCB to Agnus
socket, as well as the PCB itself. There is a small, but possible, chance
that Agnus will come outOK yet mess up the motherboard by its flexing.
Without the proper tools, remove your A2000 motherboard, the bottom
shielding, and push the Agnus out through one of the holes in the PCB
underneath the Agnus. This eliminates one of the two areas of stress I've
discussed.
-Greg
Greg:
Thanks. I had an idea that tool was a trap. From the way you describe
the action of the tool, it works as a small gear puller works. It puts an
equal and opposite force on the socket and the chip in such fashion that
much moxie can be applied without fear of breaking either.
Regards Tom
Betty:
Whattabout this….. Go to the local hardware store. Buy the largest
nut they got, at least 3/4" across. Get a bolt for the thing a few inches
long and a small set of PC-7 epoxy. Schmutz the nut to the old Agnus and
wait for it to set up. Insert bolt and pop Agnus by lifting it straight
up, just the opposite from when it was pressed in place. Well????
Regards Tom
Thomas,
Your idea is a good one, but with one flaw. Since you are "glueing" a bolt
to the Agnus chip you are introducing the prospect of static from the bolt
damaging your old chip and/or damaging something else in your machine. This
can be prevented by grounding yourself, and should be done anyhow.
There's another flaw, what if you want to re-use your old Agnus chip? How
permanent is this glue? Will your Agnus perpetually have a bolt attached to
it now?
I'd say, order your Fatter Agnus from Grapevine, it comes with a free
extractor and the whole set costs no more than if you bought it elsewhere
(for the chip alone).
Joe
Joe:
Good point. The nut that I proposed gluing to the agnus should be
insulated from it by the PC-7, which is like *extremely* thick whipped
cream. When the bolt is introduced, it is conceivable it, too, could touch
the agnus. PC-7 is *quite* permanent. But remember it is the NUT to be
attached. The bolt would be removed from the nut after the agnus is out.
You could replace the old agnus, but I can't imagine why you would want to.
I think it is socket-crack-proof at the risk of making sure you grounded
everything first.
Interesting.
Regards Tom
Thomas:
In view of all I've heard of the Agnus pulling problems, the nut and bolt
could be done safely, however the procedure would need slight modification.
You would have to get a larger diameter nut and bolt, as the bolts'
diameter would have to be the same as the agnus, so that the nut touched
only the socket, NOT the chip itself. Then what you'd have to do would be
put the nut and a washer on the bolt, and then glue the BOLT down to the
agnus chip. Once dry, by screwing down the nut, you would in effect be
levering out the agnus by pushing down on the socket while forcing up on
the agnus chip. I've never done this with an agnus chip, and I'm SURE it
wouldn't be an approved method of removal <g>, but I've done similiar
things like this all the time with other objects.
-Mike Schiller
In sunny Fort Lauderdale
Mike:
Ingenious! Gotcha! That would take care of the situation that Greg
envisioned. You have come up with the leverage to match the proverbial
small gear-puller! Hey….. shall we put some of these together and
market them as the Ultimate Agnus Remover… 😎
I guess you know what the difficulty would be. I'm not sure, but I
believe a nut and short bolt of that size would cost more than the chip! I
might just try it, though, to prove the point.
Regards Tom
Mike,
Everyone here keeps on discussing how to PULL the chip out.
That's funny because up here (Sunny Toronto,Canada) we have a totally
different approach and we have done over 25 Obese Agnus installations.
What we do is, we PUSH the chip out.
Description:
For the 2000, take everything out (Drives, Power Supply, Cage) then
take the mother board out of the case making sure to take out the brass hex
screws that hold the metal shield on. and there you will find to holes just
underneath the Agnus. Making sure you rest the chip carrier on something
solid so that when you use a blunt "pusher" (we use a miniature hex
screwdriver) to push the chip out through the two holes. Then we carefully
pull out the feelers on the carrier to a 45 degree and insert the new chip
carefully.
This process takes about half an hour, but it works for us and no extra
tools are neccessary.
Sorry if these instructions are not VERY clear.
Later…
Mike…
Mike,
Why not spend $12 on the proper tool and save about 20 minutes each
on the change? With the tool, you only have to set aside the drive
bay/power bridge and the rest is a "snap".
Don
If you really want to try that, Thomas!! (I have read of a few people who
did something along that line.)
……Betty
Joe,
Let me know how it goes. I'm very curious.
Thanks, Paul
Paul,
My upgrade went succesfully. I now have 1 meg of CHIP memory!!
Joe,
Congratulations!! I talked to my local rep and it sounds like I may have
to have more extensive mods to the motherboard. I believe (based on the
date that I bought my machine) that I have an A2000 with a rev 4.x mother
board. According to the dealer, I'll have to have some additional equipment
added to the board to make it 6.x compliant. I'll defer to the local tech
to do that. I looked at pricing this weekend. I may also have to wait on
the Agnus upgrade in favor of a 2Mb memory upgrade. I'll have to price it
out some more before making the final decision, but I want the 1Mb Agnus
absolutely.
Thanks, Paul
Paul –
I installed my own 1MB Agnus. The most difficult part is getting the old
chip out of the socket with out damaging the socket. Once you do that,
there's a jumper to move and a trace to cut. If you've messed around with
this type of thing before, it's not hard – just make sure and test the
continuity across the trace after you've cut it to make sure you have it.
If you've never done any type of circuit board work before, I personally
wouldn't recommend this to be the first 8^). But then, I'm a chicken when
it comes to expensive equipment that I don't know my way around.
Harry
Could somebody please post the information on which jumper and trace need
to be changed to activate a 1mb agnus? I've got "Super Agnus" in my 500,
but i don't believe it's configured for operation as such, since everything
just reports 512k chip memory. I don't want to haul my 500 down to the
service shop and pay them just to cut a trace and move a jumper… I've
looked around the libs for any info on this but was unable to find any.
Thanks in advance…
…mike
Mike,
On the A500, 2 traces need to be cut, and one trace (jumper) needs
to be soldered in place. One of those cuts is on an unlabeled trace in the
middle of several others. Difficult to describe or find without a sample.
I'd suggest it's worth the $$ to have a dealer's tech do it.
Don
Harry,
Between the 68000 and the kickstart rom are three small square solder marks
lined up vertically called JP1. Look closely and you will see that the top
two squares are linked with a solder trace. This trace must be cut
completetly and the bottom two squares must be linked together.
Second, Look over at the 501 ram expansion bus. Count 8 pins down from the
top and you should see a trace that ends in a solder drop to the left of
that pin. The trace to that solder drop needs to be cut cleanly.
Once these are done and you have put the amiga back together, type avail in
the CLI and you should have 1meg chip ram. I recommend that you only do
this if you have additional fast ram since some software can get buggy with
1 meg chip and no fast ram.
If you would like me to talk you through doing this, E-mail me your number
and I'll call you.
-Rick Graff
Harry,
I've messed with the guts of my equipment before, but not to the extent
that you talk about. For example, I've deterimined that I have to buy a
new fan for the power supply. Mine is a bit stickey. But I've never had
to cut a trace before. I've heard horror stories about people pulling up
entire traces, and their source traces by accident. I'm also not sure how
to test the continuity across the trace other than perhaps with a
multimeter which I don't have. I know I could cut a good chunk out of the
trace, but there could be trace e elements left over which could still ruin
the cut. Hmmm, maybe I'll check out the price of having one installed at
the shop.
Thanks for the info.
Paul
Paul,
There are two MAJOR obstacles to "Joe Average User" swapping out
the Fat Agnus for the Super Agnus in an A2000.
1. The chip carrier (socket) is a square PLCC carrier. It requires
a special tool to *properly* remove the chip. Attempting to pry the old
chip out, or using an improper tool may not only get the chip out, but
destroy the carrier. Replacing a broken carrier is an expensive
proposition.
2. A trace on the mother board must be CUT. That in and of itself
is no big deal, but the trace is very small, and quite close to other
traces. If while cutting the trace, you slip…again you'll have an
expensive repair to be done.
On top of that, the Agnus, and many of hte other chips, are very
sensitive to static. Improper handling of the motherboard, or Agnus can
lead to a dead computer.
For your information, the basic procedure is to open the computer
up, remove the power supply/drive bridge, remove the old Agnus chip, move a
jumper, cut the trace, install the power supply/drive bridge, put the cover
back on and you're done.
Don
Don,
Yea, I agree. I'm not too worried about static. I've installed memory
chips in my DEC Rainbow before, and didn't have any problems. The one that
worries me is the cut of the trace. I've never done that before. I have
pulled 64 pin CPU chips before, but never the square format chips. I guess
I'm just trying to keep costs for the upgrade to a minimum (who doesn't?),
and I really need that chip. My need to run about three different graphics
packages s simultaneously is rather pressing as I spend most of my time
waiting for floppy disks to mount and software to load on my stock 2000.
In my t-shirt business, I don't have that time to waste! 😉
Thanks for the info.
Paul
Paul,
See if you can set up an appointment with your dealer's tech, the
whole job should take no more than 1/2 hour from bringing it in, thru the
installation test and return of the machine.
The cost is up to the tech of course, but it'd probably be in the
$25 range.
Don
Paul,
I've also noticed, that with the 1 meg chip memory in my machine I can now
render Dynamic HIRES picture close to perfection. Previously, I had trouble
with scan line interference…
Joe
Joe,
I haven't seen any problems with scan line interference on the 2000, but
I'll welcome any increase in the graphics power I can get. Right now, HAM
does well enough considering my patterns are ending up on a very corse
medium, but photo perfection is better under Dynamic HAM.
Paul
Paul,
I think you probably wanted to address your question t "all", but I'll
give it a shot..
i think Agnus is a big square chip that is not as hard to get in as it is
to get the old one out. Some people have reported getting it up with
screwdriver and paper clip. Others bought a special (and not very cheap)
tool. The other thing that is important (even in the summer) is the
electro-static discharge problem… you have to be careful not to zap
anything around the chip or the chip itself. Static disharge from you to
equip can damage the components even if you don't feel a shock or see a
spark. Thats why it might be a better to have a dealer put it in…if he
zaps the equipment its his nickel!
wmc
Wayne,
Your comment about "it's the installer's nickel" may be the best insurance
policy of all. I'll have to contact the local shop to see how long the
2000 would have to be in the shop. I can't afford a lot of downtime. The
machine generates part of my income!
Thanks, Paul