May 1983: Release of the first Digital Diary, PF-3000 After its invention, the electronic calculator continued to evolve, thanks to advancements in hardware technology. Through the progression of CPU innovations from transistors, to ICs, to LSI, and through advancements in display technology from nixie tubes, to fluorescent character display tubes, to liquid crystal, the calculator became ever smaller and compact. Once the technology had nearly reached its ultimate potential, a new advancement in calculator technology was made through the utilization of software employing semiconductor memory. The prime example of this is the digital diary. In 1983, Casioês first digital diary, the PF-3000, was released. This digital diary, with its new built-in telephone book, schedule, and memo functions, was soon in demand among business people. Later models allowed the use of Japanese kanji characters; extra functions could be added with an IC card, and the devices could even be synchronized with a PC. It was the pioneering technology for today’s PDA.