GEOS 128 REU Autoboot Mysteries Unraveled

How can the Commodore 128 boot into GEOS without a cartridge or disk? Patreon: https://www.patreon.com/retrobits Channel Membership: https://www.youtube.com/retrobitstv/join Shop: https://www.amazon.com/shop/retrobits Twitter: https://twitter.com/retrobitstv Retro Bits earns money from Amazon and eBay Partner Links Inspired by @8_Bit World of Jani - https://blog.worldofjani.com/?p=1600 More From Retro Bits: https://www.youtube.com/watch?v=bKrCAJiG0LU https://www.youtube.com/watch?v=4NkL6LKpr8E Thanks to our awesome Patrons and Channel Members for their support!!! Peter (Melair) Kevin Gonzalez Jon Ingersoll John DiLiberto John Trammell Paraffine Pinay Collectibles – https://www.instagram.com/pinaycollectibles/ Josh K Vince Valenti hertz_donut Justin D. Morgan - https://youtube.com/@jdmcs jmp 0x0000 William Sullivan Ryan Brooks James Taylor FULLSET Jim Leonard [mi.low] ALVIN L BRADFORD Mark A Andrews Martin Goodwell Don Namron Peter HlaviÄka (phl) Pierre Kressmann Mitch Hoffman Rayner Daniel Pedersen Wolfgang Behrens Thomas Jager Stefan Jamie Copeland Leslie Marentette Mark Krueger John T Davis C128 Motherboard Image © Bill Bertram 2007, CC-BY-2.5 — Attribution 00:00 Introduction 00:26 GEOS128 Autoboot 01:14 REU Capabilities 03:56 The Experiment 08:19 How C128 Cartridges Work 10:50 Hints in the Manual 11:48 C128 Machine Language Monitor 14:25 Will it Boot..? 15:45 System Vectors 18:22 MMU Configuration Register 21:28 Putting it all Together 24:08 Comparing the VICE .reu Dump 28:40 Notes from the Future 29:31 "128 RBOOT" 30:17 Conclusion