Hi Doug,
Thanks for the message. You can do this a few ways.
Quote: If I interpret this correctly, A boards.txt in MyDocuments\Arduino\Hardware will take president over the boards.txt in the ArduinoIDE\Hardware path
Yes, from memory I think so. If not then please let me know. However it's very easy to clone a board and give it a new name
The speed is always taken from the boards.txt (if it exists), so you can create your own boards.txt entries with your own speed(s)
You can also use the "Defines - Project" to set a speed which vm will recognize and use as an override. This allows you to vary the speed without changing board but I would recommend the board.txt for a static board speed.
The xml system due to be released shortly will not provide additional capabilities in this area but will be useful for other future things.
Here is an example of a working ATtiny boards.txt definition running at 8mhz:-
attiny45_8.name=ATtiny45 (internal 8 MHz clock)
attiny45_8.bootloader.low_fuses=0xe2
attiny45_8.bootloader.high_fuses=0xdf
attiny45_8.bootloader.extended_fuses=0xff
attiny45_8.upload.maximum_size=4096
attiny45_8.build.mcu=attiny45
attiny45_8.build.f_cpu=8000000L
attiny45_8.build.core=arduino:arduino
attiny45_8.build.variant=tiny8
Here is a cloned example for an entirely new boards.txt entry. You can change any of it's properties.
attiny45_8V2.name=ATtiny45 v2(internal 8 MHz clock)
attiny45_8V2.bootloader.low_fuses=0xe2
attiny45_8V2.bootloader.high_fuses=0xdf
attiny45_8V2.bootloader.extended_fuses=0xff
attiny45_8V2.upload.maximum_size=4096
attiny45_8V2.build.mcu=attiny45
attiny45_8V2.build.f_cpu=8000000L
attiny45_8V2.build.core=arduino:arduino
attiny45_8V2.build.variant=tiny8