\section*{Preface}

My interest for the AVR boot-loaders begun, as some users had told
me their interest to run the transistor tester software at
some boards of the Arduino family.
Of course the transistor tester software does not run as Arduino Sketch.
The Arduino development environment Sketch is only used to show
the output of the serial interface.
The transistor tester software do not use the Arduino library.
This is not necessary to use the boot-loader.


The boot-loader is a little program, which can receive program data
from a serial interface from a host (PC) and can put this data
in the instruction storage (flash) of the micro-controller.
Because the transistor tester software use very much program storage,
the boot-loader should use as less program memory as possible for
his program.
The boot-loader should also be able to write data to the
nonvolatile data storage of the AVR, the EEprom.
So the target was specified. I search a boot-loader,
which support the writing of flash and EEprom,
but use only little space in the flash memory for it's own code.

