The Holoprobe was an upgrade of the Holoview. It allowed the viewing of holovids. Though similar to the Holoview, it was far more advanced and capable of far greater quality. The Holoprobe would use the information on the holovid to make educated guesses on what was missing or too degraded to read.
The First Doctor had a Holoprobe in his TARDIS. The inhabitants of Tarron could have developed Holoprobes several centuries after colonising and the Kephras who controlled them had similar technology, though larger and of a lower quality than the Doctor's. (PROSE: Tarnished Image)