Actually, the Mark 2 remote has the same amount of memory as the Mark 1. Marantz just took away some of the things that fill up that memory quickly. One of these being 5 character names in the LCD screen. If you look, the Mark 2 has only 4 characters available for naming the multi-purpose buttons and the Mark 1 has 5. This is how they were able to cram more commands in there. As for the Pronto, I thought it had 1 MB of memory, but I'm not sure if thats to store commands or the code for the GUI.