Corvus 500 calculator - can it operate on genuine power adaptor with no batteries?

[Geoff Quickfall]

Do not apply the original wall wart voltage to calculator without rechargeable batteries in place. Test the wall wart and you will see 9volts at the plug end. This is fed into the nicads and exits the nicads at 3.6 volts.

With the wall wart used and soldered direct to the board you will be placing a 9volt charge to the PCA. you may get away with it!

If you remove the batteries use a wall wart with a voltage around 4-5 volts.