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FIXME: The current bootloader is part of the "Original Prusa i3 MK3 Multi Material 2.0 upgrade" board definition for Arduino, see below, but the flashing of a boot loader from Arduino does not seem to work correctly. Fix it!
bootloader built for an initial timeout of 2 resp. seconds
Installing the "Original Prusa i3 MK3 Multi Material 2.0 upgrade" board into Arduino
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and reported to
https://lists.freedesktop.org/archives/modemmanager-devel/2018-July/006471.html
Preliminary .inf for windows: