How to increase Chip Ram ?

[dougal]

My A2000 has 512K Chip ram and 8MB fast ram.

How can i increase the chip ram to say 1MB ? I need 1MB cause a lot of WhdLoad games need it.

[bloodline]

Depends on your Agnus revision...

[mfilos]

Depends on the mobo and Agnus revision afaik (soz it's been many years since I owned an A2000).
The easiest solution would be an MiniMegAChip like that: http://www.amiga.org/forums/showthread.php?t=60760

[dougal]

The motherboard is Rev4 and according to WhichAmiga by Piru, the Agnus is OCS PAL Agnus 8367.

If it helps the Graphics system is Amiga ECS and the graphics chip is ECS Denise 8373.

[mfilos]

AFAIK (without being 100% sure)... you definitely need an Chip RAM addon adapter like the MiniMegAChip.

For >Rev.4 there is a hack like this but requires 5.x/6.x revision.

[dougal]

If it helps, mine has the Mono Video jack at the back. I heard that if they have this then it is not the earliest A2000 based on the A1000 and 1MB chip should be possible.

[Ral-Clan]

A DKB Megachip would be good (you'd get 2MB ChipRAM), but it is hard to find and expensive.

Just getting the "Fat Agnes" would be cheaper and even easier.  Plus it's fairly common and easy to find.

But since you already have some of the ECS chipset in your A2000, you might already have the newer Agnes it installed.  I wonder if you have to do a slight motherboard hack (i.e. cut a trace, rewire another) like that needed on the A500 to recognise the full 1MB of chipram when you have the ECS chips installed.  

A simple google search should give instructions on the A2000 motherboard hack if needed.

However, if it's true that you have a revision 4.0 motherboard - then all bets are off.  This is the German proto-board that had a design closer to that of the A1000 motherboard.  Upgrading to 1MB chipram might entail an entirely different approach.

[shaf]

The Earliest A2000's were not REV 4.x Motherboards those were B2000. The First A2000 were limited release and not expandable. CBM Canada had a trade up deal for anyone with the Early revisions. There units were manufactured in Germany and didn't have the CPU expansion slot, and used the same Agnus as the A1000 the 40 Pin Package not the Fat Agnus Package and were therefore limited to 512K of Chip Ram.

[rockape]

Hi dougal,

See   http://www.bboah.com/index.php?sid=235584&lang=en&action=artikel&cat=7&id=1849&artlang=en

There could be some help there.


Regards, Michael

aka rockape

[motrucker]

Easiest, and best way is to add a Mega-Chip 500/2000 (DKB) or a Mini-megachip (newer and can be be bought brand new) This costs a little more, but takes you all the way to 2Mb of chip RAM, and is a drop in deal.
It's an all around better solution.

[Zac67]

WhichAmiga may be wrong, but a 8367 Agnus is a DIL type and would not be upgradable.

If there's a PLCC type in place (should be with the composite output), you can very easily swap that with an ECS type, change 2 jumpers and you've got 1 MB. For 2 MB it's the Mega-chip route.

@shaf
There are (very) different rev 4 mainboards. 4.0 usually is the A1000 chipset German 2000, the A500 chipset American 4.0 rev is extremely rare. 4.1 onwards is always A500 chipset (PLCC Agnus) & Buster.

[CodePoet]

I wonder if it's feasible to build PLCC to DIP adaptors for this purpose (assuming both chips are hardware IO-for-IO compatible and just in different packages)

It wouldn't be difficult to homebrew, pretty much passive, with the possibility of a couple of def***ler caps

[LoadWB]

If you had a 4000D, you could try setting the 8MB jumper on the mobo.

[Zac67]

I wonder if it's feasible to build PLCC to DIP adaptors for this purpose (assuming both chips are hardware IO-for-IO compatible and just in different packages)

They're surely signal compatible but unless you'd want to upgrade a machine very special to you it's so much easier to get a later board (or whole machine). Actually, it might be a good idea to start with a 1200 - saves you the Megachip.

[bbond007]

The Earliest A2000's were not REV 4.x Motherboards those were B2000. The First A2000 were limited release and not expandable. CBM Canada had a trade up deal for anyone with the Early revisions. There units were manufactured in Germany and didn't have the CPU expansion slot, and used the same Agnus as the A1000 the 40 Pin Package not the Fat Agnus Package and were therefore limited to 512K of Chip Ram.

I did have a 4.3 A2000. I remember swapping the agnus for the one in my A500 to get 1MB chip ram. It was definitely a square agnus as I recall cracking the socket and having to do my first wire tie and epoxy fix... Still not enough chip RAM.. Then I got the CV64/3D which really seem to make the chip RAM go a lot further.

That 2000 worked really well(for being such an old dog), but even back then it was already pretty brittle and tarnished like it had been run in a really harsh environment.