TI-73 Link Protocol Guide - 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 = 13h.
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:	07 06 09 00 A5 13 13 60 00 75 01 95 9D 75 02	Variable header: Backup
TI:	74 56 00 00	Acknowledgement of header
	74 09 00 00	Clear to send backup
PC:	74 56 00 00	Acknowledgement of CTS
	74 15 A5 13 <13A5h bytes of data plus checksum>	Backup data section 1 (system data)
TI:	74 56 00 00	Acknowledgement of data
PC:	74 15 60 00 <60h bytes of data plus checksum>	Backup data section 2 (user data)
TI:	74 56 00 00	Acknowledgement of data
PC:	74 15 75 01 <175h bytes of data plus checksum>	Backup data section 3 (variable table?)
TI:	74 56 00 00	Acknowledgement of data

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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 = 13h (all other fields contain 0h bytes).
2				ACK
3				VAR with backup-style header and type ID = 13h.
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:	07 A2 0B 00 00 00 13 00 00 00 00 00 00 00 00 13 00	Request backup
TI:	74 56 00 00	Acknowledgement of request
	74 06 09 00 DC 16 13 35 00 71 00 37 9C 7E 02	Variable header: Backup
PC:	07 56 00 00	Acknowledgement of header
	07 09 00 00	Clear to send backup
TI:	74 56 00 00	Acknowledgement of CTS
	74 15 DC 16 <16DCh bytes of data plus checksum>	Backup data section 1 (system data)
PC:	07 56 00 00	Acknowledgement of data
TI:	74 15 35 00 <35h bytes of data plus checksum>	Backup data section 2 (user data)
PC:	07 56 00 00	Acknowledgement of data
TI:	74 15 71 00 <71h bytes of data plus checksum>	Backup data section 3 (variable table)
PC:	07 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 = 13h.
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:	07 C9 09 00 DC 16 13 35 00 71 00 37 9C 7E 02	Request to send backup
TI:	74 56 00 00	Acknowledgement of RTS
	74 09 00 00	Clear to send backup
PC:	07 56 00 00	Acknowledgement of CTS
	07 15 DC 16 <13A5h bytes of data plus checksum>	Backup data section 1 (system data)
TI:	74 56 00 00	Acknowledgement of data
PC:	07 15 00 35 <35h bytes of data plus checksum>	Backup data section 2 (user data)
TI:	74 56 00 00	Acknowledgement of data
PC:	07 15 71 00 <71h bytes of data plus checksum>	Backup data section 3 (variable table)
TI:	74 56 00 00	Acknowledgement of data
PC:	07 56 00 00	Acknowledgment ?

Silent transfers

Table of Contents

Flash Transfers