Casio BG-395 Manual — Modules 1656 / 1658 / 1979

Three owner's manual PDFs for the Casio module 1656, each a different scan (English included). Casio fitted it in the BG-395. The same documents also cover modules 1658 and 1979. For module 1656, Casio's spec sheet lists one SR1120W and a SR621W (for EL) backup cell, with 15 months of battery life and accuracy within ±15 seconds a month; the module first shipped in May 1997.