TI-86 Link Protocol Guide v1.0 - System Backup Transfers

A System Backup is one large transmission containing all user-modifiable data in the calculator. The TI-86 Graph Link software does not support backups, so there is no standard backup file format. As of November 2000, only FastLink supports the TI-86's backup capability. The proprietary file format it uses can be found in the file formats section of this documentation.

The protocol for all 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 = 0x1D.
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 <=64K)
8				ACK
9				DATA - section 3 (user data >64K - see note below)
10				ACK (see note below)
11				DATA - section 4 (variable table)
12				ACK

Note: Steps 9 and 10 are not present when the data size of section 3 (specified in the header) is zero. This depends on the TI86 ROM version.

Example (PC sending backup to TI): backup in '4 parts'

PC:	06 06 09 00 8C 36 1D FF FF 15 01 41 01 4C 00	Variable header: Backup
TI:	86 56 09 00	Acknowledgement of header
	86 09 09 00	Clear to send backup
PC:	06 56 00 00	Acknowledgement of CTS
	06 15 8C 36 <368Ch bytes of data plus checksum>	Backup data section 1 (system data)
TI:	86 56 00 00	Acknowledgement of data
PC:	06 15 FF FF <FFFFh bytes of data plus checksum>	Backup data section 2 (user data <=64K)
TI:	86 56 00 00	Acknowledgement of data
PC:	06 15 15 01 <115h bytes of data plus checksum>	Backup data section 3 (user data >64K)
TI:	86 56 00 00	Acknowledgement of data
PC:	06 15 41 01 <141h bytes of data plus checksum>	Backup data section 4 (variable table)
TI:	86 56 00 00	Acknowledgement of data

Example (PC sending backup to TI): backup in '3 parts'