"...The submitted version (62 bytes) works as is in MS/FreeDos
it is very fast though. There is another version without
sound, synced to the timer, which is 44 bytes, also working
on all Dos Versions. A size way lower than 40 bytes can be
achieved with cutting alignment and color mapping..."
(
https://www.pouet.net/prod_nfo.php?which=86986)