We've discussed DRAM implementations before. It is not hard to implement and many examples exist. I have implemented 16 bit wide DRAM for std. i8051 based MIDI audio "samplers".

I do agree that 128 to 512K SRAMs are awfully convenient for storage that looks large to a 8051 but sometime you want more. I have never implemented SDRAM but do have an "itch" to connect some to an dallas '420 or '390. Alas, that will have to wait.

Thorsten, if you're really serious, check out the info ref'd above. If you still are interested let us know.

regards,
p