RetroShield Emulates Classic 8-Bit Computers with hardware #VintageComputing #History #Emulation #AppleI #Z80 @hacksterio @8bitforce

Via hackster.io, the RetroShield emulates classic 8-bit computers when attached to an Arduino Mega compatible. Available daughtercards can socket 8-bit microprocessors such as the 6502, Z80, or 6809.

The Arduino Mega emulates the RAM, ROM, and I/O devices. It also provides a terminal connection back to the host PC. With this combination, it is possible to emulate vintage computers such as the Apple I or Commodore 64.

Emulated clock speeds are well below the original ~1 MHz with a Mega. Instead, think of this platform as “wire-wrapping in software.”

The RetroShield is developed by Erturk Kocalar of 8 Bit Force and sells for $18 (unassembled.) The kit includes a daughtercard, a socket, header pins, and an LED along with a 6502, Z80, or 6809.

With an Arduino Mega, the emulated RAM runs out quickly on more but the basic assembly program.

Find more information on the RetroShield over on 8 Bit Force’s Tindie store. Read more in the Hackster.io article here.

Adafruit note: this looks like an excellent project to try the Adafruit Grand Central board (with and without headers):

Perhaps a Grand Central can approach original processor speeds? We’d like to see!

UPDATE: Code for boards is on GitLab: 6502, Z80, 6809 – Erturk Kocalar’s main GitLab here.

Website is http://www.8bitforce.com/

Hardware is CC ShareAlike 4.0 license, software is MIT license, nice! Great work!

Kit Contents for the RetroShield6502, it is a pcb, processor, socket, and header

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 16,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org

Maker Business — How to start, manage, and fund a paid membership program

Wearables — Cheap wigs FTW

Electronics — Design for test!

Biohacking — Vitamin-C + Gelatin for Accelerated Recovery

Python for Microcontrollers — Ports, app updates – CLUEs in the NEWs and more! #Python #Adafruit #CircuitPython @circuitpython @micropython @ThePSF @Adafruit

Adafruit IoT Monthly — Physical Event Notifiers, Particle deprecates Particle Mesh and More! #Adafruit #IoT @Adafruit @AdafruitIO

Microsoft MakeCode — Through the Classroom Door with LEGO Line Follower!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


  1. Does the Grand Central have 5V I/O like the Mega256 though? Not sure those old chips will take 3.3V from a modern micro as a high level input.

    I’m pretty sure at 120 MHz you can emulate the original chip entirely in software, never mind on a 600 MHz Teensy 4. But where’s the fun in that?

  2. I personally think having the extra RAM and flash opens up the possible classic computers the boards can emulate. While an Apple I is fun for maybe 10 minutes, an Apple II or C64 clone would be very interesting.

    The logic levels may be an issue, yes. Many chips can take 3.3 as a high (check the data sheets) but the microprocessor outputs would need a level shift unless the data sheet specifies the inputs of the microcontroller are 5V tolerant.

Sorry, the comment form is closed at this time.