Merged memory takes the card and 'merges' it with onboard system memory. But you cannot merge anything more than a 128 kb card, and so the 512 will always be port memory. I think you are getting port meory confused with merged memory.

Message #2 Posted by bill platt on, 6:40 p.m., One other ? I have is that I get error massege now when I want to add another library to that ram card. I know that on slot # 1 the calculater sees only the first 128KB and cannot use the rest, but no matter if I put the card on #1 or #2 slot,the memory is always 90KB. If I take out the ram card and check the memory, it's still 90 KB. I can access the library and use the programs in the library, but when I check my available memory it's barly over 90KB. I bought a 512KB ram card to expand my memory. Message #1 Posted by sarkiss on, 6:18 p.m. Ram card on HP48GX The Museum of HP Calculators