Are you using DOSbox?
mount e e:\ -t cdrom

Correct me if I'm wrong, but I don't think the shareware version featured the full sound track..

If it's a real CD, you could try playing it in Windows Media Player or a standalone CD player. Just make sure to skip track 1, as it contains the game data.

Hezus wrote on 2021-05-16, 11:38:

Correct me if I'm wrong, but I don't think the shareware version featured the full sound track..

You were correct. I checked the CD through Windows Media Player and there weren't music at all, just some useless stuff.

Shareware was supposed to be easy to copy. At the time, most computers didn't have a CD burner, thus CD audio would have defeated the purpose.
Distributing CDs with a single shareware version was also more like a curiosity and are nowadays collector's items. Shareware versions were more commonly distributed as downloads, on magazine CDs/floppy disks, shovelware CDs or just copied to friends.

If your disc has artwork on the surface, it probably originally came in a fancy fold-out digipak with the game manual stored under a flap, just like a retail copy did. They look identical to the retail version, except rather than a full size 'big box', it was just the digipak shrinkwrapped with a 'Shareware' sticker on the front, and the unit was sold for almost nothing ($3.99 I paid for mine, I believe).

These discs do contain the audio tracks.

acridAxid wrote on 2021-05-18, 09:38:

These discs do contain the audio tracks.

That's interesting. I wonder, if the shareware version is supposed to play them, though.
Is there an encrypted full version on the disc by any chance? I've seen such CDs in the 90's which you could install by purchasing the full version key.

Marek wrote on 2021-05-19, 21:39:

That's interesting. I wonder, if the shareware version is supposed to play them, though.
Is there an encrypted full version on the disc by any chance? I've seen such CDs in the 90's which you could install by purchasing the full version key.

I think they are talking about this: https://archive.org/details/cdrom-quake-shareware. I haven't downloaded it, but it seems to have the soundtrack without needing any decryption key.

It's regular old CD audio, it wouldn't work if it was encrypted in any way (not to mention decryption would require more CPU cycles when the game was already pushing most systems to their limits).

At least some Quake shareware CDs contained an encrypted copy of the game you could purchase an unlock for. They also contained other iD games as well.

Those might be rarer as they were cracked pretty quickly.

Marek wrote on 2021-05-19, 21:39:

That's interesting. I wonder, if the shareware version is supposed to play them, though.

Yes, it's the same executable and the engine only locks you out of the other episodes based on what data is available in the installed .PAK files. The game also didn't check for the right CD, so many shareware players got a surprise when whatever audio CD they left in the drive started playing when they started the game.

Marek wrote on 2021-05-19, 21:39:

Is there an encrypted full version on the disc by any chance? I've seen such CDs in the 90's which you could install by purchasing the full version key.

Yes, a Windows application is provided that can unlock the data (requires a CC transaction and a challenge/response code from a phone agent done over a toll-free number).