This manual describes the AT89S/AT90S Series Flash MCU Starter Kit. The AVR Development Board is designed to help new MCU users get quickly acquainted with the Atmel baseline microcontrollers. The AVR Development Board can also be used to “breadboard” and try new designs before a final PCB is made. The Starter Kit has the following features: n Regulated power supply for both DC and AC voltage sources. n 8 push buttons for general use. n 8 LEDs for general use. n All AVR ports are easy accessible through header connectors. n RS-232 level converter for general use. n Serial programming of AT90S Series AVR MCUs. n Serial programming of AT89S series MCUs. n Development board for AT89C/S series MCUs. Each part of the AVR Development Board is described in detail in the following sections. Note that when the term AVR device is used in the text it also covers both the AT90S series AVR and AT89S series MCU devices, unless specifically noted.