No, because if you trash it you need to desolder the chip.

There is an internal link, which is not fitted, that enables writing to the flash chip (addresses <0x4000 are protected; the bootloader is 0x0000-0x1fff, the ID information is 0x2000-0x3fff). DO NOT fit this link (it's labelled PROT) unless you *really, really* know what you're doing. There should never be a need to fit it.

There are 2 paths for the boot; if the boot is a normal one then it jumps to 0xe000 (which *is* writable) with r0=hwrev, r1=ram (MB), r2=rom (MB). Early mk1s didn't set up registers like this though, I think (if r0 is >9 then assume it's rev3).

If the power up is a watchdog powerup (ie, powering up from deep sleep when the sleep timer expires in the power control PIC) then 0xc000 (again, writable) is called with the same r0,r1,r2; this obviously only applies to mk2/mk2a's as mk1s didn't have a power PIC.

The default action of 0xc000 code is to send a "deep sleep now" command which makes the unit go into indefinite power down (no automatic wake). This is just in case the power PIC ever thinks it has its sleep timer set - we don't use it yet.

The idea with 0xc000 code is that it can do something (check the RTC, for example) and if a condition is met then it will call e000 and cause a full boot (or boot linux with different command line options). If the condition is not met, it can sleep again. This gives very low power sleep (<5mA) but can be set to wake up with ~30s granularity if required; if it wakes up too early, you get about 200mA current drain (no display, no HDDs) for a fraction of a second before it goes into sleep mode again.

Hugo