The Hewlett-Packard Calculators Published: TST, 31 July 1974, Page 4 - Hewlett-Packard Singapore Pte. Ltd.

Hewlett-Packard introduces another uncompromising calculator: the new HP-55 Programmable Scientific. Published: The Straits Times, 10 April 1975, Page 17

The HP-65 was similar to the HP-35, HP’s first handheld scientific calculator, new features included a card reader, the slot to hold a card below the display and the second slider switch to select program or run modes. The HP-65 was HP’s fifth handheld electronic calculator. HP65 was nicknamed “Superstar”, the HP-65 was the first magnetic card-programmable handheld calculator, which is why some call it the “world’s first handheld computer.” The HP-65 could read from and write to magnetic cards, allowing the user to buy program cards from HP or save programs on cards.

HP80 was the first business calculator from HP. Display uses scientific notation, 10 digits mantissa, 2 digits exponent, red LED. Has functions for business and finance calculations, such as compound interest. 3.6v (3x AA rechargeable cells in a battery pack). 80 x 149 x 36 mm (3.2" x 5.9" x 1.4"). Launched in February 1973, the HP-80 was HP’s second handheld electronic calculator and its first business model.

The HP-45 was HP’s third handheld electronic calculator and the second scientific model. Early advertising brochures touted the HP-45 as doing “So much more. More than even our first “electronic slide rule!” The HP-45 added many advanced features to the HP’s first scientific calculator, the HP-35, including a built-in timer mode.

The HP-80 is Hewlett-Packard’s second handheld calculator and their first business calculator. It was introduced in 1973 and discontinued in 1978. This advertisement appeared in the February 1973 issue of Scientific American. Caption: Hewlett-Packard announces the most revolutionary financial device of our time: the HP-80. The first pocket calculator in the world to give you 36 different financial capabilities. Built-in 200 year calendar. Simple, logical operation. Goes everywhere with you.

The Hewlett-Packard HP-80 If you’re in business you can’t afford to be without it. HP-80 Simple Logical Operation; Save Time and Money; Calculate Your Rate of Return From an Airplane Seat. Published: TST, 25 April 1973, Page 16 - Hewlett-Packard Singapore Pte. Ltd. TST, 26 May 1973, Page 10 - Hewlett-Packard Singapore Pte. Ltd. TST, 26 September 1973, Page 12 - Hewlett-Packard Singapore Pte. Ltd.

1973.04.08 Hewlett-Packard Hewlett-Packard Produces Simple Answers To Complex Problems. For proof, see us at USAQUIP. Hewlett-Packard is displaying the entire family of calculators and peripherals at USAQUIP 73 at the exhibit hall in the Shangri-la Hotel, April 9 through April 14 (1973). Doors open at 10 A.M. Even the ‘babies’ of the family, the eminently pocketable HP-35 and HP-80, leave simple arithmetic and business calculation far behind - anytime, anywhere on their own rechargeable batteries.