Z80 CPU Bus Access

Still waiting for boards. Testing the Arduino Mega 2560 variant meanwhile, and it works really well. Code uploading seems reliable. As you can download too, the device is a more modern variant of the cassette tape recorder. Have to create a new python script to automate this, but the download option of a generic terminal program will work too.

A minor nuisance is that the command interpreter works with a line-feed as terminator, and terminals send a carriage return on Enter. Control-J works, but is way less convenient.