Thanks man. An Arduino board, like the one you indicated, I want.
However, I see it needs an USB interface.
There are ATmega with USB and bootloader on chip. Is there an Arduino (or something else) looking like the circuit in the picture but without that USB adaptor with FDTI?
As a note: The size, of the Arduino I need and the number of pins does not have to match exactly Z-80 capsule. It could have more or less pins.