Casio DB-100 / DB-100T Manual — Module 1641

One owner's manual PDF for the Casio module 1641 in English. Casio fitted it in 4 models, including the DB-100 and DB-100T — the full list is below. Casio's spec sheet lists one CR1616, with 2 years of battery life and accuracy within ±15 seconds a month; the module first shipped in May 1999.