OS upgrade files
The latest versions of the TI-Nspire and TI-Nspire CAS Operating System are available here. This article describes the format and content of the current versions (v1.1.9253 and v1.1.9170) of the .tno and .tnc files.
.tno/.tnc
A .tno/.tnc is a PK-Zip file with a custom ASCII header describing the OS update file. The PK-Zip file contains a certificate file (TI-Nspire.cer) and a .img file (TI-Nspire.img).
TI-Nspire.cer
The file follows TI's standard certificate format used on many caculator models. See TIGCC's documentation for more information (more particularly cread and cfindfield).
(Format of the following section: Field ID (hex) - size (dec) : comment. The indentation corresponds to subfields.)
350 - 298 : top-level field, similar to TI-68k's FLASH_APP_CERT (0x0300), PRODUCT_CODE (0x0320), FLASH_ROM_CERT (0x0330), etc.
- 0010 - 4 : ?
- 0100 - 4 : Revision Number (same field as for the TI-68k)
- 0260 - 140 : ?
- 0260 - 140 : A second one! The beginning and the end of the 2 fields are similar.
240 - 128 : Same field ID as in the .tno/.tnc. Certificate signature. FFF0 - 0 : END_OF_CERT
We need your help
- Find out what the unknown fields of TI-Nspire.cer mean