The Casio SF-4000 ($109.95) is a "digital diary" with a large, six-line LCD screen that displays any full month… | Graphing calculator, Square roots, Digital diary
MyCalcDB : Calculator Casio SF-4000 aka DIGITAL DIARY
CASIO SF 4000 digital diary vintage retrocomputer EUR 14,99 - PicClick IT
Found this old gem today... Vintage Casio SF-4000 'digital diary' from 1988. Featuring a whole 31,902 characters of battery backed storage. : r/retrobattlestations
1980's japan Vintage Rare Casio SF-4000 Digital Diary Organizer | eBay