Part number	Datasheet
Farnell: ?	n/a
Mouser: 692-Z84C4208PEG	Zilog, Z84C42
RS: n/a	n/a

The above part is rated at a clock speed of 8 MHz but a faster part, such as the 10MHz part shown below, can be used instead.

Part number	Datasheet
Farnell: ?	n/a
Mouser: 692-Z84C4210PEG	Zilog, Z84C42
RS: n/a	n/a

Further information can be found in the Z80 CPU Peripherals User Manual – Zilog – UM0081