HP 9810A - Introduction The desktop calculator HP 9810A, introduced in 1971, was a second HP calculator and follower of HP9100B. The CRT display at HP9100B was replaced by three-lines LED display. The calculator HP9810A has many new features like expandable ROM and RAM, label and indirect addressing (because large memory). The large program development was supported by alphanumeric program listing. Price in year 1972 was US$2470.