Perifractic asks how many 1581 disk drives were sold, and Facebook group members of "Commodore 64/128" answer with photos of their disk drive serial numbers. Become a patron: https://patreon.com/8BitShowAndTell One-time donation: https://paypal.me/8BitShowAndTell Ending music is "Bit Pair" by Bedford Level Experiment, from the album "Living Here In The Future": https://bedfordlevelexperiment.bandcamp.com/album/living-here-in-the-future 1581 Serial Numbers Spreadsheet: https://docs.google.com/spreadsheets/d/1n6Y8h68BaSaLpueSVqrsrzfD5US1TJexpwFYLVVPp88/ German Tank Problem implementation: http://8bitshowandtell.com/prg/tank1581.d64 German Tank Problem: https://en.wikipedia.org/wiki/German_tank_problem How Many C64s? https://www.pagetable.com/?p=547 Perifractic: https://www.youtube.com/channel/UC6gARF3ICgaLfs3o2znuqXA Doug @ 10 Minute Amiga Retro Cast: https://www.youtube.com/channel/UCSWXB7cc8mAtCjK8iXAJc1A Jim 64's Stupid PET Tricks: https://www.youtube.com/watch?v=PJrEYils4D8 Photos of World of Commodore 2008: https://www.lyonlabs.org/commodore/woc-2008/woc-2008.html Index: 0:00 The German Tank Problem 2:35 Collecting 1581 Serial Numbers 5:45 Into The Spreadsheet 7:28 Using C64 BASIC to calculate a few estimates 10:27 Walk through the BASIC code 14:11 Reminder about the links, and thanks!