IBM PCjr Manual page 238

6-96 Sound Test
Part 4 sounds the same as Part 2. It
starts as a low-pitched sound from
your speaker. The sound's pitch
increases smoothly until it reaches a
peak, stays steady for a second and
then diminishes until the sound is
gone. After this part of the Sound
Test is complete, a fourth speaker
with a flashing "9" underneath it
appears on the screen.
Press |/
Did you hear Part 4 of the Sound
Test?
YES - Go to Step 5.
NO - Go to Step 7.