Citizen SRP-45 programmable scientific pocket calculator from 1991

[jebem]

The SoC processor from Sharp model LI3301A Japan was once popular among the calculator manufactures and this LSI has a date code of 9109 B.
This calculator was made after 1991 week 09.




Battery electrolytes leakage marks are visible in the battery terminals.

A single legacy 200Kohm 1/8Watt pass through resistor is used here.
Edit:
Now, a brief look into the usual Russian sites is enough to find what can be done with this resistor... overclocking the machine (with battery consumption increase) can be the solution for the slowness of this LI3301A SoC processor.

The PCB references includes this "SR-35P" label.



Easy machine to dismantle when maintenance is required.
Extra care is needed to open the case when replacing the battery cells, though.
The plastic case locking pieces are very tight and can break easily.