Modifying the HP42S?

[Ken S]

I recently picked up an HP42S in fairly decent shape except for the LCD which is bleeding a bit at the top. I have already bought an HP17B with a good display (identical bezel) for next to nothing for a donor.

Since I will have to open it up I figured I would do the 32kb ram upgrade, I have found the correct chip and ordered a couple. Now I am wondering if it is worth changing the crystal to a 65.5360KHZ for the double speed while it is open. Are there any downsides to this? Will it drastically reduce battery life?

Are there any other modifications you would recommend? Any one figure out anything interesting to do with the other 28 pin chip mount?

Ken