Currently the new item is the TC511001AP DRAM Is mostly used in some mega ST's
https://www.exxosforum.co.uk/atari/store2/#0185
As always, all these chips get tested before going into my stock. I think there is nothing worse In doing a RAM upgrade for it not to work and then you wonder if your soldering sucks, or the ICs are faulty.. At least if you buy from my store, you can be rest assured it is your soldering which sucks
