In 1974 Hewlett-Packard, Palo Alto, California, introduced the HP-65, the first magnetic card-programmable handheld calculator, featuring nine storage registers and room for 100 keystroke instructions. It also included a magnetic card reader/writer to save and load programs. The price was $795.
"Bill Hewlett's design requirement was that the calculator should fit in his shirt pocket. That is one reason for the tapered depth of the calculator. The magnetic program cards fed in at the thick end of the calculator under the LED display. The documentation for the programs in the calculator is very complete, including algorithms for hundreds of applications, including the solutions of differential equations, stock price estimation, statistics, and so forth" (Wikipedia article on HP-65, accessed 03-10-2012).