80 years after D-Day, we are using a formula, used in WWII, to calculate the total number of dcc decks ever produced.

https://youtu.be/YC4S_d-7rXE?si=F2Pn5NHROwv6vwmn

How Many Digital Compact Cassette Decks Were Ever Produced ? Calculations Via A WWII Formula.

YouTube