Yesterday I went to my local Hamfest and picked up a few Z80 Processors and other goodies. While reading the datasheet I noticed something. If the data lines for the z80 are held in an active low state I will send the CPU a series of NOP (No-Operation) commands. A quick glance on the internet confirmed this and I quickly breadboarded a prototype. I used a manual pulsar as the clock source, tied data lines down and sent the four least significant bits of the address lines out to some LED’s.