Hi,
I have been looking at the datasheet for the atmega1280, and I think I have figured out most of the interface. However I can't seem to find what speed the SRAM chip must be, if I want to operate it in the "no delay" mode to keep write times down.
Thanks in advance
Have a look at page 381 "External memory timing". RD and WR pulse widths are both 115nS but you'll have to look at setup and hold times as well.
Times shown are for 8MHz, so presumably halve them for 16MHz.
so, the 15ns ram I have been looking at on ebay should be fine then, thank you.
I'd say so, as I said check out the S&H times but a RAM that fast should work with anything 
What are you making, a logic analyser?
I am putting a gameboy camera onto a robot ;D
It is a really basic camera with only 15744 pixels, but that will still need 16KB of ram per image at 8 bit resolution. I am using an external semiflash adc as well, which is why I want to keep things fast.
This is actually my first arduino project, I usually use PICs, but got fed up with having to reboot into windows.