Back in the day Casio offered a 32K RAM upgrade for several of its pocket computers. The module could be installed by the user to boost the available static RAM by 32K. These days the original RP-33 modules are rare as hen’s teeth so with the help of some friends we created our own.

The design was optimized for small scale manufacturing while keeping the features of the original RP-33 that Casio made. Each board comes fully assembled and tested. The components are soldered to a gold-plated PCB. The board is cleaned and then a 3D printed plate is glued on the bottom to act as a holder for the zebra strips and as a foot to hold the left side of the PCB (just like the original RP-33).

The three screws for holding the module in place are included.

Installation is easy.

  1. Take off the back cover.
  2. Turn off the memory backup power switch.
  3. Make sure the contacts on the computer and zebra strips are clean. Clean with a Q-tip moistened with 99% alcohol with gentle pressure if needed.
  4. Hole the computer right side up with one hand and the memory module with the zebra strips up with the other. Slip the module up into the pocket computer. This keeps the zebra strips from slipping out of place.
  5. Set the computer keyboard down on the table and install the 3 M1.7x4 screws. Be very careful when starting the screws as they are small and could be cross threaded easily.
  6. Turn the memory backup power switch on.
  7. Press the master reset on the back of the computer (if it has one).
  8. Press the ‘all reset’ on the front of the computer (if it has one).
  9. Clear the screen and type SYSTEM* and run the three RAM tests. If the test returns you back to the menu it has passed without error. If you happen to get an error take module back out starting with Step 1 above and make sure the contacts are clean and the module is centered.
  10. Press the 'all reset' again. Have fun!


Compatible with Casio models

AI-1000, FX-840P, FX-841P, FX-850P, FX-860P, FX-860Pvc, FX-870P, FX-880P, FX-890P, PB2000C, VX-1, VX-2, VX-3, VX-4, Z-1, Z-1GR