Like the TI-82 Stats.fr, the TI-76.fr is using a TI-73/83+-like PCB.
But the highest address pin of the 512Kb Flash-ROM is grounded: so you've only got 256Kb instead of 512Kb.
In theory, you could flash a TI-83+ OS.
But it's running a TI-83-like OS, and the Boot Code shortcut doesn't work, even after connecting the highest address pin.
Meaning that there is no software way (in theory) to write to the Flash-ROM.
You can check here for more informations:
http://tiplanet.org/forum/viewtopic.php?t=7621