Texas Instruments -83 Plus Silver Edion User manual

Texas Instruments Holland B.V.
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Texas Instruments U.S.A.
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Dallas TX. 75251
www.ti.com/calc© 1997 Texas Instruments
TI-83 Plus Developer Guide
Third Release
Back Front
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5.31”
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©1999, 2001, 2002 Texas Instruments Incorporated
Z80 is a trademark of ZiLOG, Inc.
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Windows is a registered trademark of Microsoft Corporation in the United States and/or other countries.
Important information
Texas Instruments makes no warranty, either expressed or implied, including but not
limited to any implied warranties of merchantability and fitness for a particular purpose,
regarding any programs or book materials and makes such materials available solely on
an “as-is” basis.
In no event shall Texas Instruments be liable to anyone for special, collateral, incidental,
or consequential damages in connection with or arising out of the purchase or use of
these materials, and the sole and exclusive liability of Texas Instruments, regardless of
the form of action, shall not exceed the purchase price of this product. Moreover, Texas
Instruments shall not be liable for any claim of any kind whatsoever against the use of
these materials by any other party.
The latest version of this Guide, along with all other up-to-date information for
developers, is available at http://education.ti.com.

TI−83 Plus Developer Guide Third Release May 28, 2002 i
Table of Contents
Chapter 1: Introduction
TI−83 PlusDeveloper Guide.................................................1
Conventions Used in this Guide........................................................ 1
Purpose of this Guide ....................................................................... 2
Structure of this Guide ...................................................................... 2
Chapter 2: TI-83 Plus Specific Information
Architecture..........................................................................3
Hardware Layer....................................................................4
Z80 CPU and Memory ...................................................................... 4
Z80 RAM Structure ........................................................................... 5
System RAM........................................................................................ 6
User RAM............................................................................................ 6
Temporary RAM................................................................................... 6
Floating Point Stack............................................................................. 6
Free RAM ............................................................................................ 7
Operator Stack..................................................................................... 7
Symbol Table....................................................................................... 7
Hardware Stack ................................................................................... 7
Flash ROM Structure ........................................................................ 8
Boot (Code) Area................................................................................10
Certification Area ................................................................................10
Operating System (OS) Area..............................................................10
Certificate List Area.............................................................................10
User APPS (Calculator Software Applications)/Data Area...................10
Swap Area/User APPS/Data Area ......................................................11
System Development Environment................................................. 11
System Routines.................................................................................11
RST Routines......................................................................................12
System RAM Areas.............................................................................12
System Flags ................................................................................12
OP1 through OP6 RAM Registers.................................................17
Safe RAM Locations for Application Use.......................................18

Table of Contents (continued)
ii Third Release May 28, 2002 TI−83 Plus Developer Guide
System Variables Area..................................................................19
System Variables that are Both Input and Output............................... 19
System Variable Characteristics .................................................. 19
Storing and Recalling System Variable Values................................... 20
System Variables that Are Output Only.............................................. 22
User RAM...........................................................................................22
Variable Data Structures...............................................................22
Numeric Based Data Types................................................................ 22
Real Data Type Structure............................................................. 23
Complex Data Type Structure...................................................... 23
Real List Data Type Structure...................................................... 23
Complex List Data Type Structure ............................................... 24
Matrix Data Type Structure .......................................................... 24
Token Based Data Types ................................................................... 25
TI−83 Plus Tokens......................................................................... 25
Program, Protected Program, Equation, New Equation, and String
Data Type Structures.......................................................................... 25
Screen Image Data Type Structure .................................................... 25
Graph Database Data Type Structure ................................................ 26
Unformatted AppVar Data Type Structure.......................................... 26
Guidelines for AppVar Usage....................................................... 26
Variable Naming Conventions.......................................................26
Variable Name Spellings..................................................................... 28
Predefined Variable Names................................................................ 28
Variables: A – Z and θ.................................................................. 28
List Variables: L1 – L6.................................................................. 28
Matrix Variables: [A] – [J] ............................................................. 28
Equation Variables: Y1 – Y0, X1t – X6t, Y1t – X1t, r1 – r6, u(n),
v(n), w(n)...................................................................................... 29
String Variables: Str1 – Str0......................................................... 30
Picture Variables: Pic1 – Pic0 ...................................................... 30
Graph Database Variables: GDB1 – GDB0 ................................. 31
Variable: Ans................................................................................ 31
User-Defined Variable Names............................................................ 31
User-Named Lists......................................................................... 32
User-Named Programs ................................................................ 32
User-Named AppVars.................................................................. 33
Accessing User Variables Stored In RAM — (Unarchived)............33
Accessing Variables that Are Not Programs or AppVars...............33
Accessing Programs and AppVar Variables..................................34
Output from a Variable Search on the Symbol Table ......................... 34

Table of Contents (continued)
TI−83 Plus Developer Guide Third Release May 28, 2002 iii
Creating Variables.........................................................................36
Storing to Variables.......................................................................39
Recalling Variables........................................................................40
Deleting Variables.........................................................................41
Archiving and Unarchiving.............................................................43
Related Routines ................................................................................ 44
Accessing Archived Variables without Unarchiving............................ 45
Manipulation Routines...................................................................49
List Element Routines......................................................................... 49
Matrix Element Routines..................................................................... 49
Resizing AppVar, Program, and Equation Variables .....................50
Symbol Table Structure.......................................................................52
Floating Point Stack (FPS)..................................................................57
Naming Convention.......................................................................58
General Use Rules.............................................................................. 58
FPS System Routines...................................................................59
FPS Allocation Routines ..................................................................... 59
FPS Deallocation Routines................................................................. 60
Copy Data To and From Existing FPS Entries.................................... 61
Drivers Layer......................................................................64
Keyboard......................................................................................... 64
Display............................................................................................ 71
Displaying Using System Routines......................................................71
Display Utility Routines..................................................................71
Displaying Text..............................................................................72
Formatting Numeric Values for Display...............................................76
Entry Points...................................................................................76
Modifying Display Format Settings......................................................77
Writing Directly to the Display Driver...................................................77
Reading the Display Driver After Setting X or Y Coordinates ........80
Contrast Control..................................................................................82
Split Screen Modes.............................................................................82
Graphing and Drawing —What’s the difference?........................... 84
Drawing...............................................................................................84
Graphing.............................................................................................84
Graphing and Drawing Utility Routines................................................84
Drawing Routine Specifics ..................................................................85
Graphing Routine Specifics.................................................................88

Table of Contents (continued)
iv Third Release May 28, 2002 TI−83 Plus Developer Guide
Graph WINDOW Settings..............................................................88
Graphing ina SplitScreen ............................................................88
Graphing Routines and System Flags...........................................88
Run (Busy) Indicator ....................................................................... 91
APD(Automatic Power Down)................................................... 92
Link Port.......................................................................................... 93
Tools and Utilities Layer..................................................99
ErrorHandlers............................................................................... 99
Nested ErrorHandlers.................................................................. 101
Utility Routines.............................................................................. 102
Floating-Point Math...........................................................................102
MiscellaneousMath Functions..........................................................104
Floating-Point Math Functions that Output Complex Results.......104
Complex Math...................................................................................105
Other Math Functions.......................................................................107
FunctionEvaluation...........................................................................108
Parse Routine.............................................................................108
Temporary Variables.........................................................................110
UsingTemporary Variables.........................................................111
ManagingTemporary Variables..................................................111
Deleting Temps and Setting (pTempCnt)....................................112
Working with TI Language Localization Applications.................... 114
Entering and Exiting an Application Properly................................ 115
Stand-alone......................................................................................115
Start-upCode..............................................................................115
Exit Code....................................................................................116
Stand-alone with Put Away Notification.............................................117
Start-upCode..............................................................................118
Put AwayCode...........................................................................120
Chapter 3: Application Development Process
Programming Layer .........................................................120
TI−BASIC Programs .........................................................................120
ASM Programs..................................................................................120
Applications.......................................................................................121
ASM versus Applications ..................................................................121

Table of Contents (continued)
TI−83 Plus Developer Guide Third Release May 28, 2002 v
Development System.......................................................121
Using the Simulator System —Requirements for Getting Started 121
Creating an Application for Debugging —One-Page and Multi-Page
Apps.............................................................................................. 122
A Brief Overview of Certificates and Application Signing.............. 122
Creating Applications that Fit On One Page................................. 122
The Hello Application........................................................................123
Accessing System Resources.....................................................123
Application Headers....................................................................123
Header Creation..........................................................................123
Calling System Routines .............................................................123
Accessing System Variables.......................................................123
Defining a String..........................................................................124
Erasing the Screen......................................................................124
Printing Text to the Screen..........................................................124
Copying the String.......................................................................124
System RAM Registers...............................................................124
Reading a Key Press...................................................................125
Exiting an Application..................................................................125
Creating a Multiple Page Application............................................ 125
Branch Table Entries.........................................................................125
Branch Table Placement...................................................................126
Branch Table Equate File..................................................................126
Making Off-Page Calls and Jumps....................................................126
Creating a Zilog Developer Studio Project.....................127
Creating the Project...................................................................... 127
Adding Files to the Project................................................................127
Project Settings.................................................................................127
Building the Application................................................................. 128
Loading the Application into the Simulator.................................... 129
Debugging the Application............................................................ 131
Signing the Application ................................................................. 134
Downloading the Application......................................................... 134
Chapter 4: Development Tools
Development Architecture...............................................136

Table of Contents (continued)
vi Third Release May 28, 2002 TI−83 Plus Developer Guide
Z80 Development System................................................136
Installation........................................................................136
TI Software Simulator and Debugger .............................136
Introduction................................................................................... 136
Installation..................................................................................... 137
Getting Started.............................................................................. 137
Breakpoints................................................................................... 141
Address Watch Points................................................................... 141
Trace Options ............................................................................... 142
CPU View Window........................................................................ 143
Disassembly View Window........................................................... 144
Flash View Window....................................................................... 145
Flash Monitor Window................................................................... 145
RAM View Window........................................................................ 146
RAM Monitor Window ................................................................... 147
Memory Map Window ................................................................... 148
Calculator Simulator Window........................................................ 148
Symbol Table................................................................................ 150
Trace Log Window........................................................................ 150
IO Log Window ............................................................................. 152
Loading Applications and RAM Files ............................................ 152
Link Settings ................................................................................. 154
Key Press Recording and Playback.............................................. 155
Save/Display/Compare Calculator Screens.................................. 156
Terminating a Session .................................................................. 156
Support in Writing Applications..................................................... 156
Glossary................................................................................... 151
TI83 Plus “Large” Character Fonts.......................................156
TI-83 Plus “Small” Character Fonts.......................................163

Figures
xviii Third Release May 28, 2002 TI−83 Plus Developer Guide
Fig. 2.1: TI−83 Plus Architecture................................................................................................ 3
Fig. 2.3: Z80 Memory Space......................................................................................................4
Fig. 2.2: TI−83 Plus RAM........................................................................................................... 5
Fig. 2.4: TI−83 Plus RAM Structure............................................................................................ 5
Fig. 2.5: TI−83 Plus Flash ROM Structure.................................................................................. 8
Fig. 2.5b: TI−83 Plus Silver Edition Flash ROM Structure.......................................................... 8
Fig. 2.6: Symbol Table Structure...............................................................................................52
Fig. 2.7: Floating Point Stack Structure.....................................................................................57
Fig. 2.8: Calculator Scan Code .................................................................................................65
Fig. 2.9: Home Screen Display Mapping...................................................................................72
Fig. 2.10: Pen Display Mapping ................................................................................................74
Fig. 2.11: Command Values......................................................................................................77
Fig. 2.12: Pixel Coordinates......................................................................................................85
Fig. 2.13: Graph WINDOW Setting ...........................................................................................88
Fig. 2.14: Error Flow................................................................................................................102
Fig. 2.15: TI−83 Plus System RAM .........................................................................................112
Fig. 2.16: Control Flow............................................................................................................116
Fig. 2.17: Event Sequence......................................................................................................117
Fig. 2.18: Application Loader Process.....................................................................................119
Fig. 3.1: Application Development Flow..................................................................................119

Tables
TI−83 Plus Developer Guide Third Release May 28, 2002 xix
Table 2.1: System Flags ...........................................................................................................13
Table 2.2: OP Registers............................................................................................................17
Table 2.3: Transfer one OP register to another (11 byte operation)..........................................17
Table 2.4: Exchange one OP register with another (11 byte operation) ....................................18
Table 2.5: Load a floating-point value into an OP register (9 byte operation)............................18
Table 2.6: Miscellaneous floating-point utility routines in OP registers......................................18
Table 2.7: Set an OP register to all zeros (11 byte operation)...................................................18
Table 2.8: Variable Name, RAM Equate, and SysTok Value.....................................................21
Table 2.9: Floating-Point Number Format.................................................................................22
Table 2.10: Variable Name Format ...........................................................................................27
Table2.11: Format of ArchiveStoredVariables........................................................................44
Table2.12: Format of ArchiveStoredVariables........................................................................46
Table2.13: Program, AppVar, Group........................................................................................52
Table2.14: Lists........................................................................................................................52
Table2.15: Real, Cplx, Mat, EQU, GDB, Pict............................................................................52
Table2.16: FormulaExample...................................................................................................54
Table2.17: Floating-Point Basic Math Functions...........................................................................102
Tab le 2.18: Trigonometric and HyperbolicFunctions ..............................................................103
Table2.19: Floating-Point Power andLogarithmicMath Functions.........................................103
Table 2.20: Floating-Point Miscellaneous Math Functions.......................................................104
Table2.21: Complex Math Basic Math Functions ...................................................................105
Table 2.22: Complex Math Power and Logarithmic Math Functions........................................106
Table 2.23: Complex Math M iscellaneous Math Functions......................................................106
Table2.24: Temporary VariablesExample .............................................................................110
Table 2.25: Language Table...................................................................................................114

TI-83 Plus Developer Guide Third Release May 28, 2002
Introduction
TI-83 PLUS DEVELOPER GUIDE
This guide contains information necessary to develop applications for the TI-83 Plus
calculator. It addresses basic environmental specifics and development guidelines. This
guide covers TI-83 Plus calculator specific information, processes, and development
tools.
The TI-83 Plus Developer Guide is one of a set of documents supporting the TI-83 Plus
calculator. The set includes:
•TI-83 Plus Graphing Calculator Guidebook — Describes how to use the calculator
(provided with the TI-83 Plus calculator).
•TI-83 Plus Tutorial — Provides examples that introduce the developer to application
creation.
•TI-83 Plus User Interface Guide — Provides information on the design and
construction of the user interface.
To access these guides visit our web site.
Conventions Used in this Guide
The following conventions were adopted for this guide to help make the material easier
to read.
Program text: All of the program examples are in a non-proportional font that can be
distinguished from the guide text.
LD HL,L1name
B_CALL Mov9ToOP1 ; OP1 = list L1 name
;B_CALL FindSym ; look up list variable in OP1
Syntax: Program instructions (commands and directives) are in all upper case letters.
Example:
B_CALL routine
Optional parameters: These parameters are enclosed in square brackets. Part of a
program instruction may be in italics to describe the type of information.
Example:
[label][:] operation [operands] [; comment]

2Chapter 1: Introduction
TI-83 Plus Developer Guide Third Release May 28, 2002
Program layout: The program statements appear in columns.
Example:
ThisIsALabel: LD A,5
B_CALL SystemRoutine ; call to a system routine
DEC A
JR NZ,ThisIsALabel
RET
Purpose of this Guide
The types of programs that can be created on the TI-83 Plus calculator include
RAM-based TI-BASIC programs, RAM-based assembly programs, and
Flash ROM-based applications. This guide addresses Flash ROM-based application
development and RAM-based assembly programs.
Structure of this Guide
•Chapter 2 provides an in-depth view of the TI-83 Plus physical and logical memory
structures, and the various drivers, tools, and utilities available to the developer.
•Chapter 3 presents several processes including the application development
process, the signature process, the testing process, and the release/distribution
process.
•Chapter 4 provides a view of the various development tools.

TI-83 Plus Developer Guide Third Release May 28, 2002
TI-83 Plus Specific
Information
ARCHITECTURE
Fig. 2.1 represents the TI-83 Plus architecture, which is composed of several layers
and elements.
Hardware
Drivers
Tools and Utilities
Programming
Fig. 2.1: TI-83 Plus Architecture
The Hardware layer contains the functional components of the unit — the Z80
processor, Random Access Memory (RAM), Flash ROM (also called Flash), Read Only
Memory (ROM), and TI BASIC (not included in this guide).
The Drivers layer contains assembly language-controlled functions such as the keypad,
battery, display, and input/output.
The Tools and Utilities layer contains the elements that provide text, drawing tools,
and utility routines.
The Programming layer contains the user interface — screen, keyboard, and the basic
unit functionality. In addition, it provides the capability to load TI BASIC programs
(keystroke), assembly programs that execute in RAM, and application programs that
execute in Flash ROM.
This chapter explains the Hardware layer, Drivers layer, and Tools and Utilities layer.
Chapter 3 explains the Programming layer.

4Chapter 2: TI-83 Plus Specific Information
TI-83 Plus Developer Guide Third Release May 28, 2002
HARDWARE LAYER
Loading and debugging an application requires a general understanding of the memory
layout of the calculator.
Other manuals and guides cover TI-83 Plus operation including keys, screens, menus,
etc. This discussion covers the TI-83 Plus internal hardware components —
Zilog Z80™ CPU, RAM, and Flash ROM.
Z80 CPU and Memory
The TI-83 Plus uses a Z80 processor with a 64K byte logical address space. To provide
more than 64K bytes of physical RAM, this logical memory space is divided into four
16K byte pages (see Fig. 2.3). Physical memory is also divided into two 16K byte pages
(see Fig. 2.3), and a physical page is mapped into each logical page as it is needed.
There are two types of physical memory in the calculator — Z80 RAM and Flash ROM.
The following sections address the composition, structure, and uses of these memory
types.
•Z80 Logical Memory Space
The Z80 logical memory size is 64K bytes, which is divided into four 16K byte
pages — 0000h to 3FFFh, 4000h to 7FFFh, 8000h to BFFFh, and C000h to FFFFh.
A physical memory page is mapped into each logical page.
FFFFh
0000h
4000h
8000h
C000h
3FFFh
7FFFh
BFFFh
16K Always RAM Page 0
16K RAM Page 0,1 or Flash ROM Pages 0-31
16K RAM Page 0,1 or Flash ROM Pages 0-31
16K Always Flash ROM Page 0
Fig. 2.3: Z80 Memory Space
The 16K byte address space from 0000h to 3FFFh is ROM page 0 from the Flash
ROM. It is always present.
The 16K byte address space from 4000h to 7FFFh is used for swapping a 16K byte
ROM page from the Flash ROM. This allows the TI-83 Plus system to extend
beyond its 64K byte physical addressing capabilities.

Chapter 2: TI-83 Plus Specific Information 5
TI-83 Plus Developer Guide Third Release May 28, 2002
•Z80 Physical RAM Structure
TI-83 Plus physical RAM consists of 32K bytes starting at address 8000h.
FFFFh
8000h
C000h BFFFh
16K Page 3
16K Page 2
Fig. 2.2: TI-83 Plus RAM
Z80 RAM Structure
The TI-83 Plus has 32K bytes of RAM. The system code partitions the RAM into a
number of areas, which it uses to maintain different types of information. Applications
that need RAM must reuse some of the RAM not currently in use by the system code.
They must request an allocation from the system code User RAM area. Fig. 2.4 shows
how RAM is partitioned.
Legend
System RAM
(Fixed Size)
User RAM
(Grows Up)
Temporary RAM
(Grows Up)
Floating Point Stack
(Grows Up)
Free RAM
Operator Stack
(Grows Down)
Symbol Table
(Grows Down)
Hardware Stack
(Fixed Size)
Addr
8000h
FFFFh
Dynamic Area
Fixed Area
Fig. 2.4: TI-83 Plus RAM Structure
Fig. 2.4 shows the addresses of Z80 logical address space. RAM is always mapped into
the 32K space beginning at logical address from 8000h to FFFFh. The areas (System

6Chapter 2: TI-83 Plus Specific Information
TI-83 Plus Developer Guide Third Release May 28, 2002
RAM and Hardware Stack) at each end of RAM are fixed size. All other areas are
dynamic. The positions of the areas in RAM with respect to each other never changes
and never overlaps; however, their sizes grow and shrink and boundaries move as the
calculator operates. The area labeled Free RAM is a leftover area. As the other areas
grow, they push into the Free RAM area making it smaller. As the other areas shrink,
the Free RAM area gets larger.
Following is a brief overview of each of these areas in RAM.
System RAM
This area contains system preallocated RAM structures.
•System Flags (Modes, Indicators)
•System Variables (for example, Xmin, Ymin…)
•OP1 through OP6 RAM Registers
•Memory Pointers
•Safe RAM Locations for Applications Use
•State Monitor Control RAM
•Graph Backup Screen — bit image
•Utility Backup Screens (two) — bit image
•Text Backup Screen
User RAM
Variables created by the calculator user are stored in User RAM. Each variable stored in
User RAM has a Symbol Table entry associated with it.
Temporary RAM
This area is used during equation parsing and execution. It contains the data for the
temporary variables that are created during parser execution. Some applications may
need to perform housekeeping of this area if they invoke the equation parser and if
temporary variables are returned as a result.
Floating Point Stack
This area is used during equation parsing and execution. It provides temporary storage
outside the User RAM area.
Free RAM
This is the RAM that is currently not in use. The arrows in Fig. 2.4 show that the
structures below and above Free RAM grow toward it.

Chapter 2: TI-83 Plus Specific Information 7
TI-83 Plus Developer Guide Third Release May 28, 2002
Note: Applications should never use this area. Information about which RAM areas are available for
applications will be provided, as well as how to create variables for long-term storage of data.
Operator Stack
This area of RAM is used by the system code for math expression evaluation and
equation parsing (execution). No detailed description of this RAM area is provided since
applications do not use the Operator Stack.
Symbol Table
This area of RAM is used to keep track of all of the variables, resident in both RAM and
Flash ROM. The names, data types, pointers to the data, and where the variables reside
in RAM or in Flash ROM (archived) are stored in the Symbol Table.
Hardware Stack
This is the area to which the Z80 Stack Pointers (SP) register points. This stack area is
400 bytes. The Hardware Stack starts at address FFFFh and it grows from high to low
memory.
There are no safeguards against overflowing the stack and corrupting other RAM areas.
The amount of space allocated for the stack should be sufficient for applications needs.
Applications should avoid the use of recursive routines that can easily and quickly
overflow the Hardware Stack. The Hardware Stack should not be used for saving large
amounts of data. Using the Hardware Stack to save register values upon entry to
routines should not cause problems.
None of the TI-83 Plus system routines use recursion that will overflow the Hardware
Stack.

8Chapter 2: TI-83 Plus Specific Information
TI-83 Plus Developer Guide Third Release May 28, 2002
Flash ROM Structure
The TI-83 Plus Flash ROM is composed of 512K bytes divided into 32 pages, each of
which is 16K bytes in size. Fig. 2.5 represents the Flash ROM structure.
00000 Addr Page(s) Size
OS 03 – 00 03 – 00 64 K
OS 07 – 04 07 – 04 64K
SWAP/USER DATA 0B – 08 11 – 08 64K
SWAP/USER APPS/DATA 0F – 0C 15 – 12 64K
USER APPS/DATA 13 – 10 19 – 16 64 K
USER APPS/DATA 15 – 14 21 – 20 32K
CERTIFICATE LIST 17 – 16 23 – 22 32 K
OS 1B – 18 27 – 24 64K
SYSTEM PRIVILEGED 1D – 1C 29 – 28 32K
CERTIFICATION 1E 30 16K
7FFFF BOOT 1F 31 16K
Fig. 2.5: TI-83 Plus Flash ROM Structure
Legend
SWAP and/or User APPS Area
Update System (OS) Area
Fixed Area — changeable only by TI

Chapter 2: TI-83 Plus Specific Information 9
TI-83 Plus Developer Guide Third Release May 28, 2002
The TI-83 Plus Silver Edition Flash ROM is composed of 2048K (2M) bytes divided into 128
pages, each of which is 16K bytes in size. The structure is generally the same as the TI-83
Plus except for the inclusion of 96 additional 16K pages (24 additional 64K sectors).
The TI-83 Plus Flash structure chart (Fig. 2.5) is correct up to page 14h; at that point, the TI-83
Plus Silver Edition includes more data pages. The TI-83 Plus Silver Edition also has OS
residing at the high 8 pages of Flash, 78h…7Fh. The TI-83 Plus high memory is 18h… 1Fh.
Fig. 2.5b: TI-83 Plus Silver
Edition Flash ROM structure
00000 Addr Page(s) Size
OS 07h – 00h 07 - 00 128K
SWAP/USER DATA 0Bh – 08h 11 – 08 64K
SWAP/USER APPS/DATA 0Fh - 0Ch 15 – 12 64K
USER APPS/DATA 13h – 10h 19 – 16 1334 K
USER APPS/DATA 67h – 14h 103 – 20 32K
USER APPS/DATA 69h – 68h 105 – 104 32K
CERTIFICATE LIST 6Bh - 6Ah 107 – 106 32 K
FUTURE OS USE 77h – 6Ch 119 – 108 192K
OS 7Bh – 78h 123 - 120 32K
SYSTEM PRIVILEGED 7Dh - 7Ch 125 – 124 32K
CERTIFICATION 7Eh 126 16K
7FFFF BOOT 7Fh 127 16K
Legend
SWAP and/or User APPS Area
Update System (OS) Area
Fixed Area — changeable only by TI

10 Chapter 2: TI-83 Plus Specific Information
TI-83 Plus Developer Guide Third Release May 28, 2002
The explanations of some Flash ROM areas below are for informational purposes only.
Boot (Code) Area
This area contains the following unalterable items.
•Boot-strap code
•System initialization code
•Software validation routine
•Program download routine
•Software product ID
•Product code update loader
Certification Area
This area contains program authentication information.
•Calculator serial number
•Unit certificate public key
•Date-stamp public key
•Date-stamp certificate
•Unit certificate and license status
•Group certificates
Operating System (OS) Area
This area contains the operating system of the calculator — math, display, keyboard,
I/O, etc. routines.
Certificate List Area
This area contains a list of unit certificates for the specific calculator.
User APPS (Calculator Software Applications)/Data Area
This area is shared by applications and variables archived by the user for long-term
storage.