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Additional Pictures 

 

The Circuit Diagram of the Clock Oscillator from a Canon Pocketronic II calculator manufactured in April 1974.

Observed signals on the OSC1, OSC2, OSC3 and CK Pins of the TMS0640 Clock Oscillator.
DUT: TMS0641NL, B 7429 @ RV1 = 50 kOhm, TH1 = 41 kOhm.

Observed signals on the OSC1, OSC2, OSC3 and CK Pins of the TMS0640 Clock Oscillator.
DUT: TMS0641NL, B 7429 @ RV1 = 100 kOhm, TH1 = 41 kOhm.

Observed signals on the OSC1, OSC2, OSC3 and CK Pins of the TMS0640 Clock Oscillator.
DUT: TMS0641NL, B 7429 @ RV1 = 0 kOhm, TH1 = 41 kOhm.


If you have additions to the above article please email: joerg@datamath.org.

Joerg Woerner, April 13, 2024. No reprints without written permission.