Casio DBC-30 / DBC-300 Manual — Module 1253

One owner's manual PDF for the Casio module 1253 in English. Casio fitted it in 5 models, including the DBC-30 and DBC-300 — the full list is below. Casio's spec sheet lists one CR2016, with 2 years of battery life and accuracy within ±15 seconds a month; the module first shipped in Jan 1995.