Hello Ray,
Thanks for your support and the hex file. I have uploaded the file and now the bootloader works and the update to the last version was done successfully (2.1.4).
I have only, for avrdude, skip the parameter B -250 because I have already during my tests set all fuses to the correct value, to works with a external crystal of 12 MHz. But your are right, without the B -250 you cannot communicate with a mcu the first time.
In my case, I have used your usbtiny programmer done with the ATtiny45. Thanks to share all informations to build it.
And I’m using the nice AVRDUDESS program. The GUI is more comfortable than the line command 😉 and you can save a configuration.
Best regards
Laurent