HP48GX RAM card design

[mfleming]

Very nice arrangement from your description. I'd love to see a picture of the other side as well. The PCB you've labeled Middle Board isn't just a spacer, there are tracks and unpopulated component pads. Was it meant to be part of the design? The cutouts look great. You might cement a plastic sheet (preferably clear!) over the top surface to keep fingers out, and with a notch to pull the battery out from the side. HP would probably have used a metal sheet for EMI shielding, a little overkill for this project

The series resistors in the data lines can be dropped. I didn't use them in my own board. They were probably added to the original design for static protection or to isolate a defective memory chip.

Nice work!
~Mark