but i didn't understand you question about the wall adapter ( the requirement part

Well, What do you think about how to power up the circuit? I used a wall adapter, rated at 18VDC and 300 mA.

why does asim khan use two 7805's (one for the 6v and the other for 5V?)

One 7805 is for powering up the circuit, and other provides VCC to the device under programming. Some ATMEL chips require 6.5 volt as VCC during programming, and during read back/verify, they require 5 V

BTW: How expensive is 7805 that you want to save one??

Remember, this programmer is for more than one device. Thats why it has plenty of VCC options.


IA