S100Computers.com S-100 Z80 CPU Board V2.1 designed by John Monahan (dated 12/16/2016). Modern reproduction/kit build of classic S-100 bus CPU card. Features Z80 bus master configuration with EzSBC.COM PSU5 power module, 10MHz crystal oscillator, ROM/IO/MEM wait DIP switches, and various TTL logic ICs (74LS series, 74F series). Fully assembled and in anti-static bag.