How to Burn Optiboot Botloader on Atmega8 With Arduino IDE 1.6.x and 1.5.x

Open boards.txt, which is in: Arduino\hardware\arduino\avr (in your main Arduino folder). Do not use MS notepad it will mess everything up. WordPad is much better, but I'm pretty shure that every decent text editor will be as good.

and add at the end :

##############################################################

atmega8o.name= Atmega8 Optoboot

atmega8o.upload.tool=arduino:avrdude1

atmega8o.upload.protocol=arduino

atmega8o.upload.maximum_size=7680

atmega8o.upload.speed=115200

atmega8o.bootloader.tool=avrdude1

atmega8o.bootloader.low_fuses=0xbf

atmega8o.bootloader.high_fuses=0xdc

atmega8o.bootloader.path=optiboot

atmega8o.bootloader.file=optiboot\optiboot_atmega8.hex

atmega8o.bootloader.unlock_bits=0x3F

atmega8o.bootloader.lock_bits=0x0F

atmega8o.build.mcu=atmega8 atmega8o.build.f_cpu=16000000L

atmega8o.build.core=arduino:arduino

atmega8o.build.variant=arduino:standard

##############################################################

You heve to be shure, that lines atmega8o.bootloader.tool=avrdude1 and atmega8o.upload.tool=arduino:avrdude1, contain avrdude1 insted of avrdude.

platform.txt is in the same directory with boards.txt. You need to find section titled:

# AVR Uploader/Programmers tools

# ------------------------------

Copy default lines and paste them after old ones. Do not delete old. Chane avrdude to avrdude1 in new prorammer settings and delete "-Uefuse:w:{bootloader.extended_fuses}:m" from line titled "tools.avrdude.erase.pattern="

Or You can simply copy my code and paste it after standard programmer settings:

#####
tools.avrdude1.path={runtime.tools.avrdude.path}

tools.avrdude1.cmd.path={path}/bin/avrdude

tools.avrdude1.config.path={path}/etc/avrdude.conf

tools.avrdude1.upload.params.verbose=-v

tools.avrdude1.upload.params.quiet=-q -q

tools.avrdude1.upload.pattern="{cmd.path}" "-C{config.path}" {upload.verbose} -p{build.mcu} -c{upload.protocol} -P{serial.port} -b{upload.speed} -D "-Uflash:w:{build.path}/{build.project_name}.hex:i"

tools.avrdude1.program.params.verbose=-v

tools.avrdude1.program.params.quiet=-q -q

tools.avrdude1.program.pattern="{cmd.path}" "-C{config.path}" {program.verbose} -p{build.mcu} -c{protocol} {program.extra_params} "-Uflash:w:{build.path}/{build.project_name}.hex:i"

tools.avrdude1.erase.params.verbose=-v

tools.avrdude1.erase.params.quiet=-q -q

tools.avrdude1.erase.pattern="{cmd.path}" "-C{config.path}" {erase.verbose} -p{build.mcu} -c{protocol} {program.extra_params} -e -Ulock:w:{bootloader.unlock_bits}:m -Uhfuse:w:{bootloader.high_fuses}:m -Ulfuse:w:{bootloader.low_fuses}:m

tools.avrdude1.bootloader.params.verbose=-v

tools.avrdude1.bootloader.params.quiet=-q -q

tools.avrdude1.bootloader.pattern="{cmd.path}" "-C{config.path}" {bootloader.verbose} -p{build.mcu} -c{protocol} {program.extra_params} "-Uflash:w:{runtime.platform.path}/bootloaders/{bootloader.file}:i" -Ulock:w:{bootloader.lock_bits}:m

#####

Remember not to use Atmega8L with this boards.txt settings.

Burning the Bootloader
If you have a new ATmega8, you'll need to burn the bootloader onto it. You can do this using an Arduino board as an in-system program (ISP). To burn the bootloader, follow these steps: Upload the ArduinoISP sketch onto your Arduino board. (You'll need to select the board and serial port from the Tools menu that correspond to your board.) Wire up the Arduino board and microcontroller as shown in the diagram.Select "Atmega8 optiboot" from the Tools > Board menu. Run Tools > Burn Bootloader > w/ Arduino as ISP. (not ArduinoISP it is not he same.) You should only need to burn the bootloader once. After you've done so, you can remove the jumper wires connected to pins 10, 11, 12, and 13 of the Arduino board.

this was modified from original arduino.cc tutorial: arduino.cc/en/Tutorial/ArduinoToBreadboard

Only difference is that you need to select Atmega8 Optoboot from tools>board

If everything was correct your Atmega8 can be used in arduino or in your standalone projects.

like for an example my nixie clock :)