It always makes me jealous when I see one of these. I put some time and money into trying to make a z80 computer, but after a burned rom chip and 2 burned 9/5 v power converters, I gave up the project.
I destroyed the UART chip today by applying power the wrong way around. Man that really pissed me off. It was such an awesome chip with two uart channels, FIFO buffer and tons of other cool features.
It forced me to go in a different direction with this computer though. I will use an eZ8 microcontroller for handling all I/O operations. The eZ8 has a lot of peripherals built in including two uart channels, timers, flash memory, adc, pwm. The only thing it lacks is the ability to execute machine code from ram. That's what the Z80 is for in this computer. The z80 will be the main CPU and the eZ8 only does the I/O.
Because the microcontroller needs time to respond to the z80 the z80 will be put in a halt state until the microcontroller is done processing the I/O request. This is similar to the way benryves solved this problem on his z80 computer.
This shows that breaking stuff is not always the end of the world.
