The major feature added in version 1.5 was support for Flash ROM. The Flash ROM provides on-board, non-volatile storage for audio, files (such as programs, multis, effects, etc.) and operating systems. It appears like a disk containing files, but has a couple of advantages: 1. It is lightning fast to load. (This is partly because audio data does not have to be loaded - it merely has to be "activated") and 2. Any data in the first eleven volumes is automatically loaded on power-up. Flash ROM can provide a good way to automatically load an operating system when the machine is switched on. This is especially relevant for the S2000 where a startup disk would otherwise be required.