Z80DevBoard

The Z80DevBoard is an advanced development board for the Z80 microprocessor, based on the RP2040.

This board combines the classic Z80 with the modern RP2040 microcontroller. The RP2040 manages the flash memory and loads programs into RAM for execution by the Z80. Real-time LED indicators provide visual feedback on the Z80's activity, making it an ideal platform for both learning and development. The board's buttons allow the user to load the Z80 program or custom firmware into memory, manually set the Z80 clock, put the Z80 into wait mode, and reset it.

Connection to the computer, used for both power and data transmission, is via a USB-C port. Two sockets are provided for expansion boards or for advanced projects. The SWD and SWCLK pins on the RP2040 are accessible to allow a fix for any firmware crashes that prevented the fix from loading over USB-C.

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Author

The author of the whole project is: Gianluca Rainis - gianluca-rainis on GitHub.

License

Hardware design files (schematics, PCB, BOM):

Licensed under CERN-OHL-S v2.0

Software and firmware:

Licensed under the MIT License

AI Disclaimer

No AI was used in this project. Everything was designed by the author.

Development Tools

• PCB Design: KiCad
• Documentation and code: Visual Studio Code

PCB Manufacturing

The Gerber files for PCB manufacturing are available in the gerber/ directory.

Project Structure

Z80DevBoard/
├── customFootprints.pretty/  # Custom footprints
├── firmware/                 # The RP2040 firmware
├── gerber/                   # PCB manufacturing files (Gerber format)
├── images/                   # Documentation images and KiCad symbols
├── .gitattributes            # Gitattributes file
├── .gitignore                # Gitignore file
├── Z80DevBoard.kicad_pcb     # PCB layout file
├── Z80DevBoard.kicad_pro     # KiCad project file
├── Z80DevBoard.kicad_sch     # Schematic file
├── LICENSE-MIT.md            # MIT License
├── LICENSE-CERN-OHL-S.md     # CERN-OHL-S License
└── README.md                 # This file

Images

Schematic Diagrams

Complete Schematic (A2 format)

Z80 Section

RP2040 Section

PCB Layout

Without Silkscreen

With Silkscreen

3D Renders

Front View

Back View

Components Table

Name	Quantity	Class	Type
Z84C00	1	Microprocessor	Through Holes
RP2040	1	Microprocessor	SMD
HM62256BLP	2	Memory	Through Holes
W25Q32JVSS	1	Memory	SMD
AMS1117-3.3	1	Power Management	SMD
USB C 2.0 port	1	Data Bus	Through Holes
74HC595	3	Data Bus	Through Holes
74HC155	1	Data Bus	Through Holes
74HCT574	4	Data Bus	Through Holes
SN74LVC245APW	3	Data Bus	SMD
TXS0104EPW	1	Data Bus	SMD
Connector 2 pins	1	Data Bus	Through Holes
Connector 2x20 pins	1	Data Bus	Through Holes
Connector 2x10 pins	1	Data Bus	Through Holes
Crystal 12MHz 20pF	1	Clock	Through Holes
Oscillator 8MHz	1	Clock	SMD
74HC14	1	Support components	Through Holes
74HC04	1	Support components	Through Holes
74HC00	1	Support components	Through Holes
Resistor 0 ohm	1	Resistor	Through Holes
Resistor 27.4 ohm	2	Resistor	Through Holes
Resistor 1k ohm	36	Resistor	Through Holes
Resistor 3.3k ohm	6	Resistor	Through Holes
Resistor 5k ohm	2	Resistor	Through Holes
Resistor 10k ohm	13	Resistor	Through Holes
Resistor 470k ohm	1	Resistor	Through Holes
Capacitors 15pF	2	Capacitor	Through Holes
Capacitors 0.1uF	13	Capacitor	Through Holes
Capacitors 1uF	4	Capacitor	Through Holes
Capacitors 10uF	2	Capacitor	Through Holes
Button	5	Other	Through Holes
Switch	1	Other	Through Holes
LED	40	Other	SMD
Diodes	24	Other	SMD
Fuse 500mA	1	Other	SMD

Components List

Microprocessors

• 1 Z84C00
• 1 RP2040

Memory

• 2 HM62256BLP (RAM)
• 1 W25Q32JVSS (Flash)

Power Management

• 1 AMS1117-3.3 (5V to 3v3)

Data Bus

• 1 USB C 2.0 port
• 3 74HC595 (Serial to 8 bit)
• 1 74HC155 (8 bit to Serial)
• 4 74HCT574 (8 bit Buffer)
• 3 SN74LVC245APW (Bus to handle the voltage differences)
• 1 TXS0104EPW (Bus to handle the voltage differences)
• 1 Connector 2 pins
• 1 Connector 2x20 pins
• 1 Connector 2x10 pins

Clock

• 1 Crystal 12MHz 20pF
• 1 Oscillator 8MHz

Support components

• 1 74HC14
• 1 74HC04
• 1 74HC00

Resistors

• 1 Resistor 0 ohm
• 2 Resistors 27.4 ohm
• 34 Resistors 1k ohm
• 6 Resistors 3.3k ohm
• 2 Resistors 5k ohm
• 12 Resistors 10k ohm
• 1 Resistor 470k ohm

Capacitors

• 2 Capacitors 15pF
• 8 Capacitors 0.1uF
• 3 Capacitor 1uF
• 2 Capacitors 10uF

Other

• 5 Buttons
• 1 Switch
• 40 LEDs
• 24 Diodes
• 1 Fuse 500mA

Firmware

Build

From the project root, run:

cmake -S firmware -B firmware/build
cmake --build firmware/build -j