Maybe https://www.ddr-museum.de/en/blog/2016/gdr-1-megabit-memory-chip https://www.ddr-museum.de/en/blog/2016/gdr-1-megabit-memory-... and https://en.wikipedia

Maybe https://www.ddr-museum.de/en/blog/2016/gdr-1-megabit-memory-chip https://www.ddr-museum.de/en/blog/2016/gdr-1-megabit-memory-... and https://en.wikipedia.org/wiki/ZMDI https://en.wikipedia.org/wiki/ZMDI ?