Those of you who still have a version of Windows with a real DOS might look for and try the QBASIC.EXE program. This program allows the PLAY command, which will produce notes from your basic computer, through your internal speaker.

With this program running, try the command, Play "O2 T50": Play "A1", and press

This tells your computer to play an "A" whole note, in octave 2, at a tempo of 50. You can lengthen the note by decreasing the "T" number, and change octaves by changing the "O" number. This is one of getting the note but it may not be a true 440 "A".

Dave