Old audio file formats

Hi there
Back in 1992-3 I put together a language learning package that used standalone exe files which operated in a DOS environment. I was using HyperPAD by Brightbill Roberts which stopped with a frozen screen, exited to DOS, played the file and resumed. Back then having sound using only the internal speaker was a bit of a triumph. My software got less and less friendly with subsequent versions of Windows (or the other way round!) but now has a new lease of life with DosBox and works perfectly on Windows, Linux, jailbroken iThings and Android. Three examples of the exe files to greet the user are here http://www.tutorscreens.co.uk/tscexefile.htm
I would like to add some new sound files. I still have the Quantech SoftSpeak software which takes sound through the parallel port but it is not liking the extended versions of DosBox which add lpt1 functionality.
So questions are:
Softspeak offers to accept .snd files. Is there any way of generating these?
or better
If you look at the exe files on the page above, do you know any way of generating files like that - and possibly of better quality?
I’m keeping my fingers crossed! Thanks in advance.

There are many different types of SND file - it’s a generic file extension for several different file types (https://en.wikipedia.org/wiki/SND_(file))
IF the file type is AU/NeXT, then you can create them by selecting “Other uncompressed files” as the file type in the Export dialog, then set “AU (Sun/NeXT)” as the header and select the appropriate encoding. Encoding for AU files is commonly (but not always) 8-bit µ-law. You will also need to set the “Project Rate” (lower left corner of the main Audacity screen) to the appropriate sample rate.

So, things that you need to know:

  1. The exact file format (for example, AU/NeXT)
  2. The required encoding (for example, 8-bit µ-law)
  3. The required sample rate (for example, 8000 Hz)

I expect the files will also need to be mono.