In fact, the unit doesn't work like this. It has no permanent battery feed, and will save where it is even if you yank it out of the dash when playing. Basically, it monitors the input voltage to the PSU. If this drops below 10v, a powerfail interrupt is generated which causes the current state information to be saved to a page in flash rom (it cycles these - you'll get at least a million saves before the flash wears out).

When it boots is checks the flash for the latest valid saved position data and continues from this point (the actual playlist is saved to a hard disk partition when a new playlist is generated/selected, as this is too big to be saved on a power fail).

Hugo
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