TI-83 Link Protocol Guide v1.0 - System Backup Transfers

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System Backup Transfers

A System Backup is one large transmission containing all user-modifiable data in the calculator. The file format that the TI-83 Graph Link software uses can be found in the file formats section of this documentation.

System backups can either be transferred manually or silently. Manual transfers require both the sending and the receiving units to be put into a special transfer mode. Silent transfers can only be done between a computer and a calculator, and require that the computer make the request or request-to-send.

The protocol for manual system backup transfers is shown below. For information on packet formats, click here.

A computer can be either the sending unit or the receiving unit.

Step | Direction | Packet
--- | --- | ---
1 |  |  |  | VAR with backup-style header and type ID = 0x13.
2 |  | ACK
3 |  | CTS or SKIP/EXIT. If exit, do step 4 and quit.
4 |  | ACK
5 |  | DATA - section 1 (system data)
6 |  | ACK
7 |  | DATA - section 2 (user data)
8 |  | ACK
9 |  | DATA - section 3 (variable table?)
10 |  | ACK

Example (PC sending backup to TI):

PC: | `03 06 09 00` `C0 0D 13 29 5C 55 01 27 93 75 02` | Variable header: Backup
TI: | `83 56 09 00` | Acknowledgement of header
| `83 09 00 00` | Clear to send backup
PC: | `03 56 00 00` | Acknowledgement of CTS
| `03 15 C0 0D` <DC0h bytes of data plus checksum> | Backup data section 1 (system data)
TI: | `83 56 C0 0D` | Acknowledgement of data
PC: | `03 15 29 5C` <5C29h bytes of data plus checksum> | Backup data section 2 (user data)
TI: | `83 56 29 5C` | Acknowledgement of data
PC: | `03 15 55 01` <155h bytes of data plus checksum> | Backup data section 3 (variable table?)
TI: | `83 56 55 01` | Acknowledgement of data

###

Silent Backup Transfers

The protocol for silently requesting and receiving a backup is described below:

Step | Direction | Packet
--- | --- | ---
1 |  |  |  | REQ with 11-byte variable header and type ID = 0x13 (all other fields contain 0h bytes).
2 |  | ACK
3 |  | VAR with backup-style header and type ID = 0x13.
4 |  | ACK
5 |  | CTS or SKIP/EXIT. If exit, do step 4 and quit.
6 |  | ACK
7 |  | DATA - section 1 (system data)
8 |  | ACK
9 |  | DATA - section 2 (user data)
10 |  | ACK
|  | DATA - section 3 (variable table?)
|  | ACK

Example:

PC: | `03 A2 0B 00` `00 00 13 00 00 00 00 00 00 00 00 13 00` | Request backup
TI: | `83 56 0B 00` | Acknowledgement of request
| `83 06 09 00` `C0 0D 13 29 5C 55 01 27 93 75 02` | Variable header: Backup
PC: | `03 56 00 00` | Acknowledgement of header
| `03 09 00 00` | Clear to send backup
TI: | `83 56 00 00` | Acknowledgement of CTS
| `83 15 C0 0D` <DC0h bytes of data plus checksum> | Backup data section 1 (system data)
PC: | `03 56 00 00` | Acknowledgement of data
TI: | `83 15 29 5C` <5C29h bytes of data plus checksum> | Backup data section 2 (user data)
PC: | `03 56 00 00` | Acknowledgement of data
TI: | `83 15 55 01` <155h bytes of data plus checksum> | Backup data section 3 (variable table?)
PC: | `03 56 00 00` | Acknowledgement of data

The protocol for silently sending a backup is shown below:

Step | Direction | Packet
--- | --- | ---
1 |  |  |  | RTS with backup-style header and type ID = 0x13.
2 |  | ACK
3 |  | CTS or SKIP/EXIT. If exit, do step 4 and quit.
4 |  | ACK
5 |  | DATA - section 1 (system data)
6 |  | ACK
7 |  | DATA - section 2 (user data)
8 |  | ACK
9 |  | DATA - section 3 (variable table?)
10 |  | ACK

Example:

PC: | `03 C9 09 00` `C0 0D 13 29 5C 55 01 27 93 75 02` | Request to send backup
TI: | `83 56 09 00` | Acknowledgement of RTS
| `83 09 09 00` | Clear to send backup
PC: | `03 56 00 00` | Acknowledgement of CTS
| `03 15 C0 0D` <DC0h bytes of data plus checksum> | Backup data section 1 (system data)
TI: | `83 56 C0 0D` | Acknowledgement of data
PC: | `03 15 29 5C` <5C29h bytes of data plus checksum> | Backup data section 2 (user data)
TI: | `83 56 29 5C` | Acknowledgement of data
PC: | `03 15 55 01` <155h bytes of data plus checksum> | Backup data section 3 (variable table?)
TI: | `83 56 55 01` | Acknowledgement of data

Silent transfers | Table of Contents | Misc

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