HP 41CX Auto-Off behavior

[rprosperi]

(11-23-2023 08:43 PM)Monte Dalrymple Wrote:  

(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.

Thanks Monte, I've wondered about this. Since the BEEP commands sound super-fast, I wondered if the shut-down timer did as well, since that feature predated the time/clock features of the TIME module and subsequent CX. Thanks for clarifying this.