Your Texas Instruments graphing calculator is a very powerful device, with two built-in programming languages that it can natively understand. The first is Z80 assembly (also known as TI-ASM), a low-level language that provides direct access to your calculator's processor. This is very dangerous if you are unfamiliar with what you are doing. Oftentimes, the calculator will simply crash, without throwing an error of any kind. If you make a mistake, you can damage your device's memory beyond repair.
There is a safer alternative to that. TI-BASIC is a high-level language. It is an interpreted language. This means that the processor reads each line before it executing the command. If you make a mistake here, the calculator will return an error. Also, one command in TI-BASIC is the equivalent of several lines of assembly code, thus making it a lot easier to use. TI-BASIC is the only language to be discussed in detail in this tutorial.
For future clarity, I will now define several terms involved in the TI-BASIC programming language. A command is a word or symbol that directs a device to perform a certain task. An argument, otherwise known as a specification, is a series of one or more values or inputs that are passed to the command to use. Some commands are comprised of arguments.
The TI calculator has two main sectors, the RAM and the Archive. The RAM is a portion of the memory that is available to programs for design and execution. As such, it is also most prone to crash. A crash is defined as a reset of memory data, due to some software malfunction. The RAM is relatively unorganized and unprotected. It is also the only part of the calculator's memory that can truly be tinkered with. RAM stands for random access memory.
It is important to note here that some of the RAM of your calculator is system RAM, reserved for use by the calculator's operating system. You cannot access system RAM without assembly; this is why only about 24 KB of the 32 KB RAM your calculator has can be used.
The structure of the Archive is very different. First off, the Archive is secured against crashes because it is locked down to prevent user interference. The Archive is structured in blocks, into which Archived variables are placed. It is not possible to write to or from the Archive memory directly, even with assembly. Special routines, such as the one packaged in TI-BASIC's Archive command, are required to modify the Archive.
TI-BASIC is generally the first language that a developing calculator programmer learns. First off, let me tell you that that because of hardware compatibility issues, the actual language is different between some calculator models. For instance, a program designed for use on a TI-83 Plus will not work on a TI-83 or lower. This game design tutorial will only cover the language that can be used on one of the following calculators.
If you are coming here to learn to code in TI-BASIC, you are in the wrong place. This tutorial is designed for those already familiar with TI-BASIC, as a crash course in game design. This tutorial will delve into the mechanics of a game, ways to accomplish games in TI-BASIC, and the debugging process. If you've never tried TI-BASIC before, you will have a migraine by the first page of Chapter 2.
