Lesson 1 - Displaying text

 

1) Install Tigcc
2)The classic "Hello!" example
3) A classic hello example with Tios function
4)The fonts of ti89/ti92+

1) Install Tigcc

        You need to download Tigcc development environment and VTi.

        Before explaining how functions work well, you must learn to use Tigcc development. It is very easy, Tigcc is well done. You must follow the steps:
- Starting Tigcc development and VTi unless you really want to use your calculator but I do not advise it otherwise it can damage your calculator. In addition, you can configure Tigcc to show it the path of VTi. After Tigcc will use directly VTi when you run your code.
- Creating a new project because your program can be more complex than one listing code.
- Creating a new C file; it is the main. :-)
- And you can rename this file so it is clearer for you.
        When you create a new C file, the template wizard is prompted on the screen and you must choose between several options. I advise you to take default options except for optimized call rom.
        Firstly you can choose the calculator. For simple program, you should have no problem. There are problems with keys, in particular, arrow keys and the size of screen but we can see this problem later.
        Secondly, you have the choice between kernel and no kernel. The kernel comes from asm; in asm it is an obligation. I advise you to take no kernel otherwise your program can have compatibility problem. A program with kernel is more powerful but the risk of failure is huge and I do not master at the moment. In addition, no kernel is an advantage whose asm does not own! After, you can and I advise you to check the option: "Optimize ROM calls". Your program is smaller and faster.
        Finally, you can return a value to the TIOS and you choose now checked option: "Done" which is the common value when you exit a program. The last option is able to save and restore the LCD what means before starting your program you have a screen and when you exit your program, the same screen is prompted.
You get:

  // C Source File
  // Created 18/05/2002; 22:35:52

  #define USE_TI89 // Produce .89z File
  #define USE_TI92PLUS // Produce .9xz File

  #define OPTIMIZE_ROM_CALLS // Use ROM Call Optimization

  #define SAVE_SCREEN // Save/Restore LCD Contents

  #include <tigcclib.h> // Include All Header Files

  // Main Function
  void _main(void)
  {
  // Place your code here.
  }

        The directives "#define ..." depends cases you checked. And #include <tigcclib.h> is a global include which includes all files of rom call functions or others definitions.
        Every time the compiler sees '//', it ignores what follows. It is a comment and it is very important to understand your program for others programmers and also for you if you come back on an old program, you understand quicker and especially if your code is very big and complex. To make a comment, there is another way: it begins with '/*' and ends with '*/'.

// first example of comments

/*
second example of comments
second line for your comments
...
*/
 

2) The classic "Hello!" example

        Let us see how to display text on the screen. On the ti89/92+, there are three different fonts. And there are several ways to display text. Firstly the most common function is ‘printf’ but it is not inevitably the quickest and smallest (for the memory). The syntax is printf("my text"). You create a new C file and you add your code between { and }. You try your code with run button or short cut: "F9".

  // C Source File
  // Created 18/05/2002; 22:35:52

  #define USE_TI89              // Produce .89z File
  #define USE_TI92PLUS          // Produce .9xz File

  #define OPTIMIZE_ROM_CALLS    // Use ROM Call Optimization

  //#define SAVE_SCREEN           // Save/Restore LCD Contents

  #include <tigcclib.h>         // Include All Header Files

  // Main Function
  void _main(void)
  {
    clrscr();  // clear the LCD
    printf("Helo!!!"); // display the string: "Hello!!!"

    ngetchx(); // wait for hit key
  }

A common C file is:
    - link directives
    - include section
    - _main()
        void _main(void) { ... } is like your main program. "(void)" means you have no argument and "void" without brackets means you return no value to Tios when you exit your program. “Void _main(void)” is the first procedure which runs, we will see later in details the notion of procedures. You write your code within { }. Theses braces are important and show the beginning and the end of your program. Usually they show the beginning and the end of your statement. Let us see the functions of this code.

        clrscr() clears the screen and puts the current print position to (0,0). You can see each new line is ended by ";", it is one of C specificity. Usually within brackets you must put arguments of function but you put nothing if the function has no arguments like here.

        printf("Hello!!!") displays the string: "Hello!!!" at the position of cursor, which initialized by clrscr() function. You must understand a string is equivalent to a text, an assembly of characters. I use string rather than text because string is a type and it is usually used in language of programming. I will explain the different types of C language in the following lesson.

        You must be careful with these two functions because theses functions do not exit in Tios. In fact, these functions are created from others functions therefore they are less fast and bigger than Tios functions. Indeed, they are described in Tigcc library and there are a code from others functions which is able to run wanted functions. The real size is this code. These functions are handier but you must be careful if you want to optimize your code.

        ngetchx() waits for hit key otherwise your program displays the string and after exits but you could not see the displaying. In addition, this function is able to give the name of hit key but I am going to explain that later.
 

3) A classic hello example with Tios function

  // C Source File
  // Created 18/05/2002; 23:43:27

  #define USE_TI89              // Produce .89z File
  #define USE_TI92PLUS          // Produce .9xz File

  #define OPTIMIZE_ROM_CALLS    // Use ROM Call Optimization

  #define SAVE_SCREEN           // Save/Restore LCD Contents

  #include <tigcclib.h>         // Include All Header Files

  // Main Function
  void _main(void)
  {
    ClrScr();
    DrawStr(0,0,"Hello!!!",A_NORMAL);

    ngetchx();
  }

        ClrScr() clears only the LCD. You must be careful because in C language, a majuscule is different to a miniscule. For insistence, clrscr() is different to ClrScr(). What means ClrScr() keeps the position of cursor and if you use printf, the string do not inevitably display at the left and the top of screen.

        DrawStr(0,0,"Hello!!!",A_NORMAL) print the string at the position (0,0). A_NORMAL is the way of printing which is the default printing. If you want another position, for example DrawStr(x,y,"Hello!!!",A_NORMAL), x is the number of pixel from left screen and y is the number of pixel from top screen. The different ways of printing are:
A_NORMAL: the character is ORed into the destination
A_REVERSE: the region created by inversing the character replaces the destination
A_REPLACE: the region defined by the character replaces the destination
A_XOR: the character is XORed into the destination
A_SHADED: the character is masked so that every other pixel is turned off then ORed into the destination
But if you want to have other details I advise you to look at Tigcc documentation, especially it is hard to remember all details, for example the different ways of printing and it is easier to look Tigcc documentation than to remember the real syntax when you program. Remember that the work of Zeljko Juric is wonderful and it would be wise not to use it!

ngetchx() you should be able to understand otherwise you need come back previous point. At the moment, remember that Tios waits a hit key
 

4) The fonts of ti89/ti92+

        There are three different fonts on ti89/ti92+. You can select your font with the function: FontSetSys(short font). The argument of this function is:
- F_6x8, which means the width of font, is 6 pixels and the height of font is 8 pixels. This font is mono-spaced also all characters have the same width. This is default font.
- F_8x10, which means the width of font, is 8 pixels and the height of font is 10 pixels. This font is mono-spaced also all characters have the same width. The size of this font is the tallest.
- F_4x6, which means the width of font, is 6 pixels and the height of font is 8 pixels. This font is variable width also all characters have not the same width. For example, the character 'i' is smaller than the character 'w'. The size of this font is the smallest.

        If you change the font, you get default font when you exit the program. We can see an example, it is easier to understand.

  // C Source File
  // Created 19/05/2002; 13:38:49

  #define USE_TI89              // Produce .89z File
  #define USE_TI92PLUS          // Produce .9xz File

  #define OPTIMIZE_ROM_CALLS    // Use ROM Call Optimization

  #define SAVE_SCREEN           // Save/Restore LCD Contents

  #include <tigcclib.h>         // Include All Header Files

  // Main Function
  void _main(void)
  {
    clrscr();

    printf("Here, the default face\n");
    FontSetSys(F_6x8);
    printf("Always the same font\n\n");

    FontSetSys(F_4x6);
    printf("The smallest font\n\n\n");

    FontSetSys(F_8x10);
    printf("The tallest font");

    ngetchx();
  }

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