HP 41CX Auto-Off behavior

[Monte Dalrymple]

(11-23-2023 06:26 PM)rprosperi Wrote:  Is it possible this is a double-speed CX? Using [XEQ] "BEEP" is the simplest way to check.

The auto-off time is controlled by a small capacitor on the CPU board, but the oscillator itself is on the display driver chip on the main board. The capacitor controls the frequency of a dedicated oscillator; circuitry counts the pulses and deactivates the DPWO line when the count limit is reached. This function is independent of the CPU frequency.