need to find right ODBC driver - "sybase" possibly v11

I have been tasked with supporting an obsolete, post-EOL product that uses a sybase database as the backend. I am looking for the correct ODBC driver to connect to the db via DSN. The biggest problem is that I'm not 100% sure what version of "sybase" db is used, and then a secondary problem is that althought the newer drivers are pretty easy to find, I am having trouble finding drivers that work for old databases.

Details on the db install: the old system I am supporting is a Nortel Symposium v4. Nortel went out of business I think 7 years ago, and back then they were on v7, so this is a pretty old system. Old notes from my company suggest that this system might have had a "Sybase v11" database, maybe 11.5. Now I thought "Sybase database" and "Sybase ASE database" were two different things and my internal notes from years ago refer consistently to just "Sybase", but I have seen some references on the internet suggesting that I should be looking for "sybase ASE".

When I tried to install the old ODBC drivers that were in my company's archives, I get a message from Windows (server 2012) that the setup.exe won't run on this version of windows. Changing the compatibility settings had no effect.

so to sum up: I need a 32-bit ODBC driver for Sybase (possible "Sybase ASE" v11 or 11.5) that I can install on Win2012. Am I searching for the wrong search parameters or looking in the wrong place? Does this sound like an impossible task?

Jared