HP-56

In the 1970s, the Advanced Products Division (APD) in Cupertino California built handheld calculators and several other divisions of HP built computers and peripherals. The Loveland Division (Later Calculator Products or CPD) was sandwiched between the two making "calculators with computer-like power". At the high-end there was overlap between CPD's "calculators" which spoke BASIC and the products from the computer divisions. (They were "calculators" because "computers" of the same price often needed several levels of additional management approval to purchase.) There was also overlap on the low-end models like the HP-46 which was functionally, an HP-45 with a printer. During the development of the HP-56 and 66, the divisions were still jockeying for position and defining their charters. At one point Loveland defined "programmability" as being part of their charter, but APD soon created programmable handhelds. The product numbers suggest that the HP-56 and 66 might have originally been thought of as the printing equivalents of the HP-55 and 65 but by the time the design studies shown below were made, any such linkage was obviously gone. (The tape drive in the HP-66 being the most obvious clue.)