Calculate fuse bits to ultra minimal atmega8 standalone

hello, please help me to calculate fuse bits to standalone atmega8 from here pay attention to comments peoples say that high_fuses=0xc2, not high_fuses=0xc4 like in an article, so my correct boards.txt looks like:

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

atmega8noxtalfast.name=ATmega8A (8MHz int. RC osc, short bootloader delay, 38400 baud rate)

atmega8noxtalfast.upload.protocol=stk500
atmega8noxtalfast.upload.maximum_size=7168
atmega8noxtalfast.upload.speed=38400

atmega8noxtalfast.bootloader.low_fuses=0xe4
atmega8noxtalfast.bootloader.high_fuses=0xc2
atmega8noxtalfast.bootloader.path=atmega8a
atmega8noxtalfast.bootloader.file=ATmegaBOOT.hex
atmega8noxtalfast.bootloader.unlock_bits=0x3F
atmega8noxtalfast.bootloader.lock_bits=0x0F

atmega8noxtalfast.build.mcu=atmega8
atmega8noxtalfast.build.f_cpu=8000000L
atmega8noxtalfast.build.core=arduino:arduino

it works fine for me, BUT now i have an USBtinyISP, so i'd like to burn sketches without the bootloader, please help me to calculate fusebits to use internal oscillacor at 8MHz and maximum use of flash memory (is that possible to use 8192 bytes?)

for now i use following configuration

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

atmega8noxtalfast2.name=[usbtinyisp] ATmega8A (8MHz int. RC osc)

atmega8noxtalfast2.upload.using=arduino:usbtinyisp
atmega8noxtalfast2.upload.maximum_size=7168

atmega8noxtalfast2.bootloader.low_fuses=0xe4
atmega8noxtalfast2.bootloader.high_fuses=0xc2
atmega8noxtalfast2.bootloader.path=atmega8a
atmega8noxtalfast2.bootloader.file=ATmegaBOOT.hex
atmega8noxtalfast2.bootloader.unlock_bits=0x3F
atmega8noxtalfast2.bootloader.lock_bits=0x0F

atmega8noxtalfast2.build.mcu=atmega8
atmega8noxtalfast2.build.f_cpu=8000000L
atmega8noxtalfast2.build.core=arduino:arduino

p.s. by the way, why internal oscillator don't used by default in arduino?

Mihail_:
p.s. by the way, why internal oscillator don't used by default in arduino?

Because it runs twice as fast with a 16 MHz crystal or resonator?

use this calculator AVR® Fuse Calculator – The Engbedded Blog to get the correct values for your fuses

johnwasser:

Mihail_:
p.s. by the way, why internal oscillator don't used by default in arduino?

Because it runs twice as fast with a 16 MHz crystal or resonator?

And because the timing is much less reliable. In fact I've heard it's under spec for serial communication, so serial might not even work reliably with the internal osc.

putyn:
use this calculator AVR® Fuse Calculator – The Engbedded Blog to get the correct values for your fuses

thanks for link, but i stil don't know how to use it - how to set boot flash section = 0 (i don't use bootloader at all - right?) and how to calculate free space to scetches (can i use all of 8192 bytes?) also - should i use startup delay option without bootloader (+64 msec)?

i'm newbie, so peoples - could you help me to calculate it for this time?

i don't think you need to worry about the boot settings since your not going to use the bootloader (i may be wrong here)
ive used an atmega8 with the internal oscillator and and ive selected the 8mhz start up time: 6ck + 64ms setting and it worked great

why don't you do some testing :stuck_out_tongue: unless you set your fuses to use an external clock source or external rc oscillator i don't think you can break your atmega8