NP-41 Emulator (may be)

[Chris Chung]

+Guenter and all

In key test mode, the following keys has additional functions.
+, -, turns up and down charge pump voltage, thus controls contrast.
X, toggle between charge pump and Vcc for LCD biasing, if display nothing during cold start, charge pump may be failed. And press this key can switch back to Vcc to get back the display.
/, Buzzer test.
R/S , toggle display 12 zeros as display test.