Thanks to their high performance, Flash program memory, integrated hardware functions and low power consumption, Atmel AVR microcontrollers are becoming increasingly popular, even in the semiprofessional area.The AVR series of microprocessors is based on Flash program memory and thus can be easily programmed using an SPI interface. The ability to reprogram the program memory (up to 1000 write cycles) makes these devices very attractive for use in the semi-professional area.The documents and tools that you need for programming these microcontrollers, such as an assembler and debugger, can be obtained free of charge from the Internet site www.atmel.com. These tools are for use with the Windows operating system (95/98/NT). You won’t find any development tools that run under MS-DOS here, which is a good reason for requiring the programmer and associated software to work under Windows.