Chapter 1. Diving into calculator programming
Figure 1.1. Common Texas Instruments graphing calculators, the TI-83+ (left) and TI-84+ Silver Edition; the lessons in this book apply to these calculators as well as the TI-83+ Silver Edition, the TI-84+, the TI-Nspire with a TI-84+ keypad, and, to a large extent, the TI-83.
Figure 1.2. The basic building blocks of a computer and a calculator. Both have input and output; both have long-term and short-term storage. Both have a processor (CPU) that acts as the brains and mediates communication between the other pieces. The two types of devices are similar; the ovals highlight the main differences, such as that a calculator has flash memory for long-term storage instead of a hard drive.
Figure 1.3. Output of Hello World program
Figure 1.4. Creating a program named HIWORLD
Figure 1.5. The source of HIWORLD, on a calculator
Figure 1.6. The output of the Hello World program again, as in figure 1.3
Figure 1.7. The quadratic equation for finding the roots of 0 = ax2 + bx + c (top). The samples show a = 1, b = 2, c = 1 (left), which yields a single real root, and a = 1, b = 4, c = 5 (right), which yields distinct but imaginary roots.
Figure 1.8. Source code for prgmQUAD typed into a calculator