A language comprises of two distinct facets – the spoken sound and the written script.
The spoken sounds of a language can be written using different scripts.
The language spoken during Mahabharata times was similar to the present Samskrt language.
Samskrt can be written in any of these scripts. It is also written in Roman script in which case it is called Roman with diacritics.
When ppl think of ancient scripts, they immediately think only of Brahmi. Brahmi is the name of script that was used in North India about 2000 yrs ago.
It was a writing script. Many ancient Pali and Samskrt texts can be found in this script. The edicts of Ashoka are in this script.