HP 48SX invalid data message

[bsala]

Many thanks to both mfleming and Guiseppe for the reply. I had almost give up so thank you. Of
course my first attempt at both your fixes failed because I had (unknowingly) set the write protect swtich ON - oops. But that was quickly fixed and I now have a working RAM card again.

Actually, I have the Insights books, and found the page 105 description. It's been a long time since I read these, but they and the original manuals are the best manuals I've ever read.

This machine seems timeless, so it will now get more use again - thanks guys.
Brian