Sunday, September 26, 2010

Apple IIgs 1mb memory expansion to 4mb conversion

In the past a post to comp.sys.apple2 referred to this site: which documents how someone converted a common 1mb apple memory expansion card to 4mb using 30 pin simms. Recently, I also found another guy who did the same thing but not using 8/9 chip simms .

Since I do not have any 30 pin simms lying around I did not undertake this conversion. Recently I found some simms on ebay for under $10. I decided that maybe it's time to try this out.

This is how a card would look before the conversion:

The directions said to remove all the dram chips, sockets and capcacitors:
Here are the simms we're going to use:
We use double sided tape to attach the simms:
Then follow the schematic diagram. This is how it looks after the address lines are hooked up:
After several hours it's finally finished:

Lets plug it in:

Running the memory testing program from:

I'm leaving this running overnight to see if it produces any errors.