Casio CR-16 / CS-16 Manual — Module 25

One owner's manual PDF for the Casio module 25 in English. Casio fitted it in 4 models, including the CR-16 and CS-16 — the full list is below. Casio's spec sheet lists one 393, with 12 months of battery life and accuracy within ±10 seconds a month; the module first shipped in Jun 1978.