Texas Instruments TI89 Developer Guide - Page 48

6 Chapter 2: The 68000 TI AMS Operating System Overview Many operating system routines are available to the application as shown in Figure 2.2. The address of the jump table, a table of Operating System entry points and data structures, is stored in memory location 0xC8. Through the jump table, applications, and ASM programs can access low-level device drivers, the event manager, memory manager, symbol table manager, graphical user interface library, computer algebra system, math package, and utility routines. Event Manager Graphical User Interface Library Applications Jump Table Symbol Table Manager Computer Algebra System Low-Level Drivers: Power, LCD, Memory Manager Keyboard, Link Port, Timer Math Package Utility Routines Figure 2.2: Application/OS Interface TI-BASIC programming language provides ease of programming at the expense of speed and control of every calculator feature. ASM programs are routines written in C or 68000 assembly language, both of which give the software developer much greater control over the calculator. ASM programs can be called from TI-BASIC and executed from the Home screen author line. ASM programs are generally small (≤ 8 K for AMS 2.03 and ≤ 24 K for AMS 2.04) and execute in RAM. They are intended to offer the same speed and efficient hardware access as Flash applications but as subroutines called from TI-BASIC instead of fully integrated applications. TI-89 / TI-92 Plus Developer Guide Not for Distribution Beta Version January 26, 2001