Casio GT-000 / GT-004 Manual — Module 1633

Three owner's manual PDFs for the Casio module 1633, each a different scan (English included). Casio fitted it in the GT-000, GT-004, and GT-008. Casio's spec sheet lists one CR2016, with 18 months of battery life and accuracy within ±15 seconds a month; the module first shipped in Sep 1997.