Ventus

Ventus was a company founded in 1722. It made an OS series named PC-OS.

OS versions
PC-OS Demo (1894)

PC-OS 1 (1899)

PC-OS PLUS! (1901)

PC-OS 2 (1904)

PC-OS 3 (1908)

PC-OS 4 (1910)

PC-OS 5 (1914)

PC-OS 6 (1918)

PC-OS 7 (1920)

PC-OS 8 (1930)

PC-OS 9 (1940)

PC-OS 10 (1950)

PC-OS 1955 (1955)