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Author Topic: Upgrade Ram to 1 MB Amiga 500?  (Read 17229 times)

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Offline Matt_H

Re: Upgrade Ram to 1 MB Amiga 500?
« on: April 18, 2010, 06:29:43 PM »
ECS Agnus introduced the ability to switch between PAL and NTSC in software and expanded the maximum amount of chip RAM to 1MB (2MB later on with the 500+, 600, and 3000). ECS Denise added the SuperHiRes, Multiscan, and Super72 screenmodes.

Odds are good you already have an ECS Agnus, in which case you should just be able to pop in some trapdoor RAM and get 1MB of chip RAM. Type 'avail' in a shell to see how your machine has configured your RAM. If you have WB 2.x, run ShowConfig to learn more about your chips.
 

Offline Matt_H

Re: Upgrade Ram to 1 MB Amiga 500?
« Reply #1 on: April 19, 2010, 02:07:48 AM »
Quote from: Tenacious;554322
I enjoyed the depth of detail of your ECS timeline.  I only stumbled over the following.



This contradicts my memory of a modification I did 15 years ago to my rev 6a A500.   I installed the 2 Meg Agnus (8372B) directly into the socket.  I removed the 4 motherboard ram chips and installed 4 new ram chips.  There is now 2 megs on the motherboard.  The trap door board was retained for RTC only, its memory disabled.

This A500 is still alive and well and obviously my favorite.  IIRC, this mod came to me out of one of the old magazines, but I believe it is now available on Aminet as well.


Yep, Amazing Computing ran a tutorial on that mod. It's definitely possible to wire in a 2MB Agnus (without a MegaChip), but it's far from a drop-in replacement.