Owner manual / English
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Casio Module 53 Manual
Two owner's manual PDFs for the Casio module 53, each a different scan (English included). Casio's spec sheet lists one 392, with 12 months of battery life and accuracy within ±10 seconds a month; the module first shipped in Jun 1978.
Module specs
Battery: 392 (silver-oxide)
Rated battery life: 12 months
Rated accuracy: ±10 sec/month
Casio service manual ref: S/M-108
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