Casio Flip Top FTP-30 Calculator/Databank
Not so smart as the other Flip Top
The analog part is completely separated from the digital part. A separate small cell drives the analog part, SR626SW. And a rather hard to find CR1620 drives the digital part which contains a Databank 50 Memo function including a Calculator. The watch chip that I am 100% is on the same chip too, is not utilized, thus the digital part has no time nor alarm nor stopwatch nor timer function. This was definitely a very quick development for the mass market.
Important Note when
replacing the CR1620
Please follow the complete procedure for replacing the batteries as indicated on the inner back of the digital watch. I skipped the second step (Databank Reset) because I was curious to know whether the Cmos eventually held my 8 year old Databank information. The result was a weird display of 68-50 when pressing the N/S Capacity button and the Databank would not let me enter any data too. The calculator worked flawlessly after the Circuit Reset (AC short for 2 seconds). You will lose your data when replacing batteries, I doubt that there is a way around. But at least that keypad is quite comfy, so the data can be entered quite quickly.
1. Short the AC Terminal and the + side of the batterie with a pair of metal tweezers for 2 seconds (CIRCUIT RESET)
2. Now the display will show "RESET?". Important: you have to press the SET (+) button on the keypad, otherwise the Databank function will not be reset properly and you will not be able to enter data.