It’s based on the C65 prototypes (https://en.m.wikipedia.org/wiki/Commodore_65) from 1990/1991. Not sure about “modern”, the modern keyboard layout was arguably established by the IBM Enhanced Keyboard (https://deskthority.net/wiki/IBM_Enhanced_Keyboard) introduced in 1985/1986, so roughly at the same time the now-retro C128 and the Amiga were introduced (who had vaguely similar keyboards).