PockEmul play sound by generating the sound wave directly from the emulated CPU.
Because the synchronization is not perfect, some glitch may appears in the produced sound.
The PockEmul session file is available at https://pockemul/com/pockemul/sessions/osaka.pml
This 1 bit music, played by a LM program to drive the directly the piezo is a wonderful sample of what those little machines was capable of.
Find more information on this at osaka :: pouët.net (pouet.net)
The music played by an original PC-1403 is here