TI-83+ Link Protocol Guide v1.1 - File formats

The TI-83+ Graph Link software stores variables in several types of files. Single variables are stored in files that have an extension that corresponds with their type. Groups of variables are stored in files with the extension ".8Xg". However, all of these file types have a common format.

The different file types and contents that the TI-83+ Graph Link software can read and write are shown below.

Extension	Description
.8Xc	TI-83+ complex number
.8Xd	TI-83+ GDB (function, polar, parametric or sequence)
.8Xg	Multiple TI-83+ variables of varying types (group)
.8Xgrp	TiLP only: TI83+ 'group' variable
.8Xi	TI-83+ picture (image)
.8Xk	TI-83+ FLASH application
.8Xl	TI-83+ list
.8Xm	TI-83+ matrix
.8Xn	TI-83+ real number
.8Xp	TI-83+ program
.8Xq	TI-83+ FLASH certificate
.8Xs	TI-83+ string
.8Xt	TI-83+ table setup
.8Xu	TI-83+ FLASH Operating System
.8Xv	TI-83+ Application Variable
.8Xw	TI-83+ window settings (Window or RclWindow)
.8Xy	TI-83+ Y-Variable (equation)
.8Xz	TI-83+ zoom (saved window settings)

The TI-83+ variable file format

The TI-83+ variable file format has two parts: a header and several variable entries.

The header appears at the beginning of the file and takes the following format:
Note - All 2-byte integers are stored little-endian Intel-style (least significant byte first).

Offset	Length	Description
0	8 bytes	8-character signature. The signature is always "**TI83F*".
8	3 bytes	3-byte further signature. These three bytes always contain {1Ah, 0Ah, 00h} = {26, 10, 0}
11 (Bh)	42 (2Ah) bytes	Comment. The comment is either zero-terminated or padded on the right with space characters.
53 (35h)	2 bytes	Length, in bytes, of the data section of the file. This number should be 57 (39h) bytes less than the file size.
55 (37h)	n bytes	Data section - consists of a number of variable entries (described below).
55 (37h)+n	2 bytes	File checksum. This is the lower 16 bits of the sum of all bytes in the data section.

Each variable entry follows this format:

Offset	Length	Description
0	2 bytes	Always has a value of 11 or 13 (Bh or Dh).
2	2 bytes	Length, in bytes, of the variable data.
4	1 byte	variable type ID byte (see variable type ID's)
5	8 bytes	Variable name, padded with NULL characters (0h) on the right.
13 (Dh)	1 byte	Version. Usually set to 0 (present if first bytes are Dh).
14 (Eh)	1 byte	Flag. Set to 80h if variable is archived, 00h else (present if first bytes are Dh).
15 (Fh)	2 bytes	Length, in bytes, of the variable data (This is a copy of the value in offset 2)
17 (11h)	n bytes	Variable data. Click here for variable data formats.

The TI-83+ backup file format

The TI-Graph Link software for the TI-83 does not have backup capability. However, the calculator itself does. The following format is not readable by TI's software.

Here is the format for backup files that FastLink & TiLP uses (it's the same format than the TI82/83 one):

Offset	Length	Description
0	8 bytes	8-character signature. The signature is always "**TI83F*".
8	3 bytes	3-byte further signature. These three bytes always contain {1Ah, 0Ah, 00h} = {26, 10, 0}
11 (Bh)	42 (2Ah) bytes	Comment. The comment is either zero-terminated or padded on the right with space characters.
53 (35h)	2 bytes	Length, in bytes, of the backup header and the data sections. This number should be 17 (11h) bytes more than the sum of the lengths of the three data sections as reported in the backup header.
55 (37h)	11 bytes	The backup header (format described below).
66 (42h)	2 bytes	Length, in bytes, of the first data section.
68 (44h)	x bytes	First data section.
68 (44h)+x	2 bytes	Length, in bytes, of the second data section
70 (46h)+x	y bytes	Second data section.
70 (46h)+x+y	2 bytes	Length, in bytes, of the third data section
72 (48h)+x+y	z bytes	Third data section
72 (48h)+x+y+z	2 bytes	Checksum. This is the lower 16 bits of the sum of all bytes from offset 55 (37h).

The backup header has this format:

Offset	Length	Description
0	2 bytes	Offset to data length: Always has a value of 9.
2	2 bytes	Length, in bytes, of the first data section.
4	1 byte	Type ID: Always has a value of 19 (13h).
5	2 bytes	Length, in bytes, of the second data section.
7	2 bytes	Length, in bytes, of the third data section.
9	2 bytes	Memory address

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The TI-83+ FLASH file format

A FLASH file usually contains between 1 and 3 headers with data and the header has the same format than the TI89/92+ one.
Headers can contains : license or data (app/os/certificate).

The header takes the following format :
Note - All 2-byte and 4-byte integers are stored little-endian Intel-style (least significant byte first).

Offset	Length	Description
0	8 bytes	8-character signature. The signature is always "**TIFL**".
8	2 bytes	Revision number (BCD coded): major.minor.
9	1 byte	Flags (usually set to 00h).
10 (Ah)	1 byte	Object type (00h).
12 (Ch)	4 bytes	Binary-Coded-Decimal date such as {dd, mm, yy, yy} for 'dd/mm/yyyy'.
16 (10h)	1 bytes	Name length
17 (11h)	8 bytes	Application name or 'basecode' for OS (zero terminated unless 8 characters long).
25 (19h)	23 bytes	Filler (unused, set to 00h).
48 (30h)	1 byte	Device type (TI73: 74h, TI83+: 73h, TI89: 98h, TI92+: 88h)
49 (31h)	1 byte	Data type (os: 23h, application: 24h, certificate: 25h, license: 3Eh)
50 (32H)	24 bytes	Filler (unused, set to 00h).
74 (4Ah)	4 bytes	Size of data in bytes. Beware: this is size of intelhexa data (in characters), not of pure data (in bytes).
78 (4Eh)	n bytes	Data.
78 (4Eh)+n	2 bytes	Checksum. This is the lower 16 bits of the sum of all bytes in the variable data.

By roms: the part below is preliminary, I will have to finish it...
You are strongly encouraged to take a look at the TI's "TI83+ SDK guide" (sdk83pguide.pdf) and more particularly the "Hardware Layer" section.

1) Data encoding:

Data are formatted in a particular way. TI used the 'INTEL Intellec 8/MDS' format, a very popular format used for transferring data to EPROM programmers, CPU emulators, ...
Format:

 

   +--Number of bytes 
   | +--Address (called 'page address' or 'address    field' in this doc) 
   | |    +--Block type (00: data, 01: end) 
   | |    |  +--Data 
   | |    |  | 						     +-- Checksum 

   | |    |  |						     |
: 10 0000 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00 CR/LF 
: 10 0010 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 CR/LF    
: 10 0020 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF E0 CR/LF 
: 00 0000 01 FF -> end block

Meaning:

- TI specific block, contains the FLASH page number (1D here): :02 0000 02 001D FC

- data block (page address = 4000h): :20 4000 00 80 0F 00 00 6C 24 80 12 01 04 80 21 01 80 31 01 80 48 43 42 4C 45 78 70 6D 74 80 81 02 80 90 03 D9

- end block: :00 0000 01 FF

Each block has an address field. Depending on the operation (App or Os) and the part, the address of the data block can be used as is (absolute addressing without using offset) or not (relative addressing, relocated at @4000h if offset=4000h for instance). Page number is sent as encoded in the specific block.

2) Parts

An app has one part. The part is made up of several blocks: specific blocks, data blocks and an end block. Data are sent with page adress 4000h aka @4000h (offset=0). The page number is specified in the specific block. The flag always equals 80h (FLASH).

An OS has several parts:
- the first part is the OS header information. It is made up of a data and an end block. It is sent with page address 0000h aka @0000h (offset=0), page number 0000h.
- the second part is the data. It is made up of a specific, a data and an end block. It is sent with page address 0000h modulo 4000h (offset 4000h) aka @4000h.
- and the third part is the digital signature of the data block. It is made up of a data and an end block. It is sent with page address 0000h aka @0000h (offset=0), page number 0000h. About flag, the first and third block have Fl=80 (FLASH), the second one has always Fl=00 (RAM).

Data are sent to calcs block per block. A incomplete block may need to be filled.
It will be filled with:
- 0x00 for App,
- 0xff for OS.

 

Variable Formats

Table of Contents

Tokens and Characters