The PC speaker noise for Pirates! is awful, but the version of DOSBox that GOG has packaged (0.74) has a bug with the Tandy mode where the ocean graphics are completely messed up. There is a fix for this, but it's not in the "stable" build. I'm guessing GOG is waiting for a new stable build before they fix it, but in the meantime, the SVN builds fix it (at least for me with vanilla build r3927).

Here's where I found this out: http://www.vogons.org/viewtopic.php?f=33&t=35913
Here's a link to the DOSBox wiki on SVN builds: http://www.dosbox.com/wiki/SVN_Builds
There are links to sites where you can download the builds.

Hope this helps some people. Be sure to go into the .conf to change the machine type to tandy as well, or else it won't work.

Thanks man. Five years later and I still had to download a SVN build to fix it!

As of this writing, Pirates! on GoG (original) comes with 0.74-2.1 which has the Tandy mode bug (black oceans).
The latest release of DosBox is 0.74-3, which also has the Tandy mode bug.
The latest SVN is r4371 which resolves the issue.

Cheers!

Is this also an issue in Dosbox Staging?

this works fine if you set the property
[dosbox]
machine = tandy

[speaker]
tandy = on

for any dosbox version ive tested
you cannot change machine=tandy while running, it has to be in the config before starting dosbox
ie config -set "dosbox machine=tandy" it doesnt work.


as for the "horrible" EGA version audio, set your cpuspeed down to 880 or 864
#config -set "cpu cycles=864"
config -set "cpu cycles=880"

these should set the audio nearly correct for a 286/386 emulation. the audio is not cycle frame matched to the graphics engine in the IBM version (cga/ega)