Amstrad CPC 8255 PIO

Simple 8255 PIO board compatible with the Amstrad CPC and MX4 connector.

Objective

Prototyping board to Learn about the 8255 PIO, and how to write Z80 assembly using an Amstrad CPC.

Background

Part of a number of modular cards using Z80 associated peripherals and the Amstrad CPC.

Backplane

CPC Amstrad Expansion Backplane by revaldinho

IO Addressing

The IO Address can be selected using two sets of jumpers (CS_HB and CS_LB), supporting the following base address.

• F8E0 and F8F0
• F9E0 and F9F0
• FAE0 and FAF0
• FBE0 and FBF0

See CPC Wiki IO Port Summary for a list of known IO ports used on the Amstrad CPC.

Testing

The 8255 PIO board has been built and has been tested on an Amstrad CPC 6128.

PCBs

PCBs are available from Seeed Studio V2.0 or Seeed Studio V3.1

Components

This Digi-Key List contains all components excluding the 8255 which was purchased from EBay.

Note the right angled header for the port connections was not available at the time of producing this list but all other components were in stock for shipping immediately.

Assembler

RASM

Resources

CPCWiki

Z80 Application by James W Coffron ISBN 0-89588-094-6

Acknowledgements

@revaldinho

Don Prefontaine

Peter Murray

@EdouardBERGE

Release History

Version 2.0

• First Release

Version 3.1

• KiCad created version of PCB.