Casio Databank, which was a huge hit about 40 years ago as a "pocket-sized memory bank." - Model Name: PF-7100 10th Anniversary Model - Memory Capacity: 1985 characters - Display: 12-digit dot matrix display Pocket size: 10.5cm x 6.5cm Katakana display - Since the operation has not been confirmed, it is listed as "junk." By the way, the instruction manual states that it requires two CR-2025C batteries and one CR-1220 battery (photo 9).