I remember those chips as they were the ones in the ZX81 16K RAM Pack. 8 of the little beauties. The RAM Pack itself was a nightmare. If it wobbled the compute

I remember those chips as they were the ones in the ZX81 16K RAM Pack. 8 of the little beauties. The RAM Pack itself was a nightmare. If it wobbled the computer would crash. I held mine on with blu-tack - lots of it. Every now and again I'd have to take it off and clean the contacts by rubbing the oxide layer off with an India rubber. It used to run quite hot too. Despite the problems, the RAM pack was the best upgrade I had!