Retrotronik RAM card for HP 48GX

[grbrum]

I just bought 3 128kb cards about a month ago (first I bought one and then the other two). The 1 and 2mb were in stock the first time but I wanted to check if it would work. They were out of stock the second time around (bummer). I messaged him on the order page - I received the cards but no answer to my message.
Finally one of the cards is acting weird (losing data inside the calculator). I messaged him with no response.
I’m hoping he is on vacation or something because I want to buy more.