> TBH had I known too many of the specifics of the platform by now they would be forgotten or I wouldn't be able to mention them!

Thanks anyways! :)

> This was/is common for most RTOS type environments where MMUs were not a thing. For example, the whole point of Brew and J2ME was to provide some level of separation prior to the later Symbians and then Android/iOS etc.

Right - although all the S5L series chips used in the later iPods had an MMU (other than the S5L8701 in the Nano 2G, which only had an MPU). They also had a pretty tight boot chain (all stages signed/encrypted). It's a weird contrast to the pretty lax security measures within the OS itself :). But I guess reworking the old iPod codebase (which started with PortalPlayer chips) to make use of the MPU/MMU would have been too much effort.