1meg Agnus in A500
Rick Keller
I have a friend with an A500 who is working on getting
it running on the net. He upgraded to 3.1, and we have
gotten Miami running ok as well.
Now, he would like to get more chip ram so that browsing
is somewhat do-able. He says that he has a Fat Agnus
chip, but that the full 1 mb hasn't been enabled on it.
Does this sound plausible? An Amiga shop (long since closed)
told him they coulb enable the full meg (for a price, of course!)
easily. How can this be done?
Any help is gratefully appreciated!
-Rick
<TSB>
Rick Keller
Buffalo, NY USA
ke...@earthlink.net
<TSB>
Taglines are pointless
Geirmund Eidet
>-Rick
Geirmund Eidet
Geirmund Eidet
[A500 -> 1MB chip]
> Next is the Gary chip. Pin1 is in the upper right corner of the chip.
>Counting counter clockwise find pin 32. Once you have marked it remove the
>Gary chip from the board and CAREFULLY using needlenose pliers or something
>like that bend the pin straight out from the chip. Reseat the chip into the
>socket. Just to the left of Pin32 you will see three soldier pads. Soldier a
>wire from pin32 of the Gary chip to the closest of those three soldier pads.
I never did that to my Gary chip on my rev6a motherboard.
Why?
Do you know the diffrense about 8372a and 8375 ? What is 8375 able to do that
the 8372a isn't ?
> Thats it! Now you need to remember that you have to soldier REALLY
>QUICKLY or you run the risk of damaging the chip/motherboard. Also be sure
>that you are grounded while doing this or you could "zap" a chip. Use this at
>your own risk. It worked for me but I give no promises that it wont blow your
>A500 into a million little pieces. I admit that I have only done this once
>but it worked great. Once you are done you will see the increase of Chip RAM
>immediately. Enjoy!
It really isn't that dangerous. I did this hack with my 40W soldering iron,
without any grounding chain or anything. The copper-circuits were actually
boiling;) And it does work!
But as you say, it IS best to be on safe side..
Geirmund Eidet
Allan Hall
OK, first a major goober, I forgot to mention that this is for the
most popular motherboard in the A500, the Rev5. You can find the revision
number in the lower right corner just below the floppy drive. Rev6 boards I
do not think require this modification at all. Sorry for the confusion. As I
am fairly new to Amigas I have no idea what the difference in chips you refer
to is. Sorry again :-(
On 05 Jul 98 22:08:03 +0100, Geirmund Eidet wrote:
:>[A500 -> 1MB chip]
:>
Rick Keller
On the subject of Re: 1meg Agnus in A500, Allan Hall was heard to say
> OK, first a major goober, I forgot to mention that this is for the
>most popular motherboard in the A500, the Rev5. You can find the revision
>number in the lower right corner just below the floppy drive. Rev6 boards I
>do not think require this modification at all. Sorry for the confusion. As I
>am fairly new to Amigas I have no idea what the difference in chips you refer
>to is. Sorry again :-(
Thanks, Allan.
We are going to take a shot at it on Tues. He does have a Rev5 momboard, as well
as the 8372a Agnus. So, we've got three (maybe 4) shots at it! -- He's got 3 A500's
as well as a spare momboard!!
Wish us luck!
-Rick
He's not a complete idiot - several parts are missing.
Ron Wilgenbusch
Here's a link to website with instructions to do the 4 chip on momboard chip
ram upgrade.
http://www1.omnitel.net/savel/amiga/upgrade.html
I have another question about this though.
Let's say he upgrades his motherboard with the 4 256K chips and does the
mods to give him 1 meg of chipram. Good to go.
Then adds a megachip (8375 agnus + 1 meg chip) to give him 2 megs chip. Good
to go.
Question: Can he then add a A501 expansion board to get a clock and 512K of
fast ram, or will this conflict with the 512K he added with the 4 chip
upgrade?
Rick Keller wrote in message <767.491T12...@earthlink.net>...
David Oakes
RW> Question: Can he then add a A501 expansion board to get a clock
RW> and 512K of fast ram, or will this conflict with the 512K he
RW> added with the 4 chip upgrade?
It'll conflict. Both 512ks will be trying to use the same memory
addresses. If you get the 501 and disable the 501's onboard memory
(sorry, it's been way too long since I worked on 500's and can't
remember which line into the 501 should be cut), you'll still be able
to use the clock though. I don't remember anyone selling just a clock
for the trapdoor, that'd be the easiest way.
--
-->>Remove the period between ns and tn to reply<<--
David Oakes | /// Member: | mailto:doa...@fox.ns.tn.ca
Dartmouth NS | \\\/// Team |
Canada | \XX/ AMIGA | Fidonet: David Oakes@1:251/11.1
--
I derailed my train of thought - hundreds were killed.
-*- ASTG 1.9
Clockmeister
David Oakes <doa...@fox.ns.tn.ca> wrote in article
<898.492T11...@fox.nstn.ca>...
David Oakes
> EXRAM line ?
I think so, but as I said, it's been a long time since I worked on
500s. I do remember that it's got to be cut on the 501 and not on the
motherboard though. Then you get the fun of taking the shielding off
of the 501, which isn't always easy to do.
>> RW> Question: Can he then add a A501 expansion board to get a
>> clock RW> and 512K of fast ram, or will this conflict with the
>> 512K he RW> added with the 4 chip upgrade?
>>
>> It'll conflict. Both 512ks will be trying to use the same memory
>> addresses. If you get the 501 and disable the 501's onboard memory
>> (sorry, it's been way too long since I worked on 500's and can't
>> remember which line into the 501 should be cut), you'll still be
>> able to use the clock though. I don't remember anyone selling just
>> a clock for the trapdoor, that'd be the easiest way.
--
-->>Remove the period between ns and tn to reply<<--
David Oakes | /// Member: | mailto:doa...@fox.ns.tn.ca
Dartmouth NS | \\\/// Team |
Canada | \XX/ AMIGA | Fidonet: David Oakes@1:251/11.1
--
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-*- ASTG 1.9
Rick Keller
was quite easy!
-Rick
<TSB>
Rick Keller
Buffalo, NY USA
be...@net.bluemoon.net
<TSB>
If at first you don't succeed, destroy all evidence that you tried.
Allan Versaevel
> Here's a link to website with instructions to do the 4 chip on momboard chip
> ram upgrade.
>
> http://www1.omnitel.net/savel/amiga/upgrade.html
My God man! Are you mad ? :)) There is an easier way.
The trap door mem (512k) can easily be added on Rec 5 or 6 motherboards to
give you 1 Meg. A jumper by the ROM has to be modified as well as one
by the Trapdoor slot. E-mail me if you want the instructions.
I have successfuly done this modification to to my A500 and coutless
others.
This "hack" was Commodore legal. They wrote it. Many 500's
were shipped with 1 Meg Agnuses. But never enambled. Beacause 500's
where shipped with only 512K as standard.
Geirmund Eidet
>I think so, but as I said, it's been a long time since I worked on
>500s. I do remember that it's got to be cut on the 501 and not on the
>motherboard though. Then you get the fun of taking the shielding off
>of the 501, which isn't always easy to do.
What? You have do modify the A501 too, on the rev5, to add 512kb to chip ?
Never heard THAT before.. Anyway, opening the box is easy. If you look at the
box, you will notice that it's simply soldered together.
>>> RW> Question: Can he then add a A501 expansion board to get a
>>> clock RW> and 512K of fast ram, or will this conflict with the
>>> 512K he RW> added with the 4 chip upgrade?
>>>
>>> It'll conflict. Both 512ks will be trying to use the same memory
>>> addresses. If you get the 501 and disable the 501's onboard memory
>>> (sorry, it's been way too long since I worked on 500's and can't
>>> remember which line into the 501 should be cut), you'll still be
>>> able to use the clock though. I don't remember anyone selling just
>>> a clock for the trapdoor, that'd be the easiest way.
Geirmund Eidet
Geirmund Eidet
>was quite easy!
Hope you get no trouble with this hack.
My experience was that the graphic started bugging, but didn't cause me any
big troubles. I was just annoying..
Geirmund Eidet
David Oakes
>>> EXRAM line ?
>>I think so, but as I said, it's been a long time since I worked on
>>500s. I do remember that it's got to be cut on the 501 and not on
>>the motherboard though. Then you get the fun of taking the
>>shielding off of the 501, which isn't always easy to do.
GE> What? You have do modify the A501 too, on the rev5, to add 512kb
GE> to chip ? Never heard THAT before.. Anyway, opening the box is
GE> easy. If you look at the box, you will notice that it's simply
GE> soldered together.
No, the question was could the original poster add memory directly to
the motherboard and use the A501 memory at the same time. The answer
was no, they would conflict. It was offered that they could disable
the memory on the A501 and then still use the clock from it, by
cutting the EXRAM line on the A501.
As for the A501 shielding being easy to remove, I think that depends
on when it was made. I had one that practically disintegrated in my
hands when I removed the shielding, while others withstood the removal
with great ease.
--
-->>Remove the period between ns and tn to reply<<--
David Oakes | /// Member: | mailto:doa...@fox.ns.tn.ca
Dartmouth NS | \\\/// Team |
Canada | \XX/ AMIGA | Fidonet: David Oakes@1:251/11.1
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with your beer and sandwich.
-*- ASTG 1.9
Greg Tallent
>>Thanks to everyone who posted, we got it done in about 20 minutes. It
>>was quite easy!
>Hope you get no trouble with this hack.
>My experience was that the graphic started bugging, but didn't cause me any
>big troubles.
Then you should double check to see if the traces that needed to be cut were
COMPLETELY cut. Take a magnifying glass and see if any of the trace is left
on the board. Also make sure that the solder connections are correctly done
and are clean.
>I was just annoying..
When were you "just annoying"? :)
>Geirmund Eidet
<TSB>
Greg Tallent |Amiga2000 GVP 040/33mhz/3.1 26 megs,2 gig/OpalVision |
gwt @ gte.net |Supra 28.8k, Lightwave 5.0, SCSI-Zip, Picasso II 1Meg|
We don't need no STINKING TAGLINES.
Geirmund Eidet
>>>I think so, but as I said, it's been a long time since I worked on
>>>500s. I do remember that it's got to be cut on the 501 and not on
>>>the motherboard though. Then you get the fun of taking the
>>>shielding off of the 501, which isn't always easy to do.
GE>> What? You have do modify the A501 too, on the rev5, to add 512kb
GE>> to chip ? Never heard THAT before.. Anyway, opening the box is
GE>> easy. If you look at the box, you will notice that it's simply
GE>> soldered together.
>No, the question was could the original poster add memory directly to
>the motherboard and use the A501 memory at the same time. The answer
>was no, they would conflict. It was offered that they could disable
>the memory on the A501 and then still use the clock from it, by
>cutting the EXRAM line on the A501.
>As for the A501 shielding being easy to remove, I think that depends
>on when it was made. I had one that practically disintegrated in my
>hands when I removed the shielding, while others withstood the removal
>with great ease.
I see.. I fairly remeber there was one or two jumpers inside it, yes..
As we're still talking about it.. To get 2MB chip, what do I have to do then?
Wasn't there something about upgrade the Gary too..?
Geirmund Eidet
Dpence
and with the trap door expanxion it went to 1.5 meg total...and adding the 512k
is really just converting it to a A500+
Geirmund Eidet
>>>was quite easy!
>>Hope you get no trouble with this hack.
>>My experience was that the graphic started bugging, but didn't cause me any
>>big troubles.
>Then you should double check to see if the traces that needed to be cut were
>COMPLETELY cut. Take a magnifying glass and see if any of the trace is left
>on the board. Also make sure that the solder connections are correctly done
>and are clean.
>>I was just annoying..
>When were you "just annoying"? :)
:) /It/ was just annoying!
Geirmund Eidet
John Luberti
Bruce Abbott wrote:
> Dpence <dpe...@kih.net> Wrote:
> >Are you sure about the memory conflicting??..I thought an Amiga500+ had 1meg
> >chip and with the trap door expanxion it went to 1.5 meg total...and adding
> >the 512k is really just converting it to a A500+
>
> The A500+ has a 2MB Agnus. It is possible to have both 1MB on the A500
> mainboard and the trapdoor expansion, but you need to add some circuitry
> to multiplex the DRAM strobes and map the extra on-board RAM to a different
> address.
>
> I have done this to a couple of A500s. Apart from the DRAM chips, 3 small
> logic chips and 14 wires need to be soldered onto the motherboard.
>
> ------------------------------------------------------------------------
> Bruce Abbott http://www.hawkesbay.com/hcw/ bhab...@inhb.co.nz
> ------------------------------------------------------------------------
Dont know where you heard the A500 plus has a 2mb agnus, but its not so. The
A500plus came stock with 1 mb of ram. 512k of that went to a 1mb agnus chip that
was wired for 512k. to get 1mb agnus you needed to cut some leads on the mother
board. 2 get a 2mb agnus on ANY A500, u needed to due some serios hacking on the
motherboard or buy a DKB MegaChip2000. No A500, or A2000 ever came with a 2mb
agnus as stock.
John Luberti
Bruce Abbott
DAMIR
> A500plus came stock with 1 mb of ram. 512k of that went to a 1mb agnus chip that
> was wired for 512k. to get 1mb agnus you needed to cut some leads on the mother
> board. 2 get a 2mb agnus on ANY A500, u needed to due some serios hacking on the
> motherboard or buy a DKB MegaChip2000. No A500, or A2000 ever came with a 2mb
> agnus as stock.
>
> John Luberti
Sorry John but this is not true. In front of me I have European A500+
(motherboard revision 8A) with stock 2 Meg Agnus chip (8375) which
allows you to have 2 Megs of Chip Ram.
However, there were no such machines ever released in the U.S.
Damir Dardagan
DA...@prodigy.net
David Oakes
JL> Dont know where you heard the A500 plus has a 2mb agnus, but its
JL> not so. The
JL> A500plus came stock with 1 mb of ram. 512k of that went to a 1mb
JL> agnus chip that was wired for 512k. to get 1mb agnus you needed
JL> to cut some leads on the mother board. 2 get a 2mb agnus on ANY
JL> A500, u needed to due some serios hacking on the motherboard or
JL> buy a DKB MegaChip2000. No A500, or A2000 ever came with a 2mb
JL> agnus as stock.
I don't know where you got your info, but it certainly isn't correct.
You might be thinking of some bundle C= offered, which included an
8372A Agnus and an A501 and they just happened to call the A500 Plus
bundle. Bruce et al were talking about the A500+ though, which *was*
released with a 2 Mb Agnus.
The A500+ was mainly sold in Europe. It came with a 2 Meg Agnus (part
number 8375 -2) and 512K of memory. Special memory cards for the belly
slot were available which had 1.5 Megs of memory. The motherboard
revision for all A500+ machines sold was Rev. 8. At the time of its
release, and for months afterwards, it was practically the only the
thing that the UK Amiga magazines talked about.
--
-->>Remove the period between ns and tn to reply<<--
David Oakes | /// Member: | mailto:doa...@fox.ns.tn.ca
Dartmouth NS | \\\/// Team |
Canada | \XX/ AMIGA | Fidonet: David Oakes@1:251/11.1
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-*- ASTG 1.9
John Luberti
> Sorry John but this is not true. In front of me I have European A500+
> (motherboard revision 8A) with stock 2 Meg Agnus chip (8375) which
> allows you to have 2 Megs of Chip Ram.
> However, there were no such machines ever released in the U.S.
>
> Damir Dardagan
> DA...@prodigy.net
COOL!! had heard of rev8 mb, but was not aware of the 2mb aganus. what other
goodies were on this A500+?
My first Amiga was an A500+ like i had described befor. Now I feel cheated.
I have learned something new about an old miggy. :)
John
Lonnie McClure
stated:
> Dont know where you heard the A500 plus has a 2mb agnus, but its
> not so. The A500plus came stock with 1 mb of ram. 512k of that went
> to a 1mb agnus chip that was wired for 512k. to get 1mb agnus you
> needed to cut some leads on the mother board.
You seem to be unaware of what an A500+ (Revision 8 motherboard)
actually is. These DID INDEED come with a 2meg Agnes chip, with 1meg of
RAM onboard, with a additional 1meg bellyboard expansion available, and
were fitted from the factory with the 2.04 ROM. These were never sold in
the United States, and about the only way a US resident would have one is
by either having imported one, or purchasing the REV8 motherboards
Paxtron had for a while, and fitting it into an A500 case.
=================
lmcc...@ibm.net
Dpence
fast ram conflicting if you add 512k chip ram to the mother board.....I had been
thinking of adding the chip ram but if it's gonna conflict then there's no point since
I already have the 1meg
John Luberti
Lonnie McClure wrote:
> In article <35AA7318...@idt.net>, John Luberti (gow...@idt.net)
> stated:
>
> You seem to be unaware of what an A500+ (Revision 8 motherboard)
>
>
> =================
> lmcc...@ibm.net
I was unaware, but I do know now. Damar has enlightend me, and I'm most
impressed with A500+ rev8
John