Looking back 80's and 90's

Altairduino simulates Altair8800 that uses Arduino due (or Mega) to emulate 8080 board and other peripherals that is collectively known as Altair8800

Altair 8800 Simulator

This is Altair 8800 simulator powered by Arduino due (or Arduino mega with lesser degree of simulation)

Project is developed and maintained by Mr. David Hansel.

You can browse to Mr. Hansel's website to get more detailed information of this amazing project.

Also, Mr. Chris Davis at Adwater and Stir sells a kit to build everything at a reasonable price.