2024/02/28 - Ran out of all stock. I'm working on getting a new batch built. Stay tuned.

My Brain-In-A-Jar Project

• A daughtercard with a real 8bit microprocessor, plugged into Arduino Mega.
• Arduino Mega emulates system hardware such as ROM, RAM, I/O devices.
• Real microprocessor executes code.
• Clock speed is about 200kHz.
• 200KB ROM space available in Arduino.
• 6K RAM available in Arduino (can be expanded to 128KB - see my blog).
• Any existing Arduino shields (LCD, SDCard, etc.) can be used to add new features.
• Compatible w/ my Teensy Adapter for RetroShield for faster clock (>1 Mhz) and more memory (256 KB RAM).

What can you do with it?

You can run the following:

• MON85 monitor, Copyright 1979-2007 Dave Dunfield, Version 1.2 - 2012 Roman Borik

Or design your own hw platform in Arduino.

What do you get?

Two options:

• Assembled and tested board w/ microprocessor
• Kit for you to build: PCB w/ surface mount parts soldered + microprocessor* + socket/header/LED

Sorry no PCB's, because 8085 is running below the min clock frequency specified in datasheets and I need to send you screened microprocessors.

NOTE: ARDUINO PICTURE SHOWS 6502, BUT YOU WILL GET RETROSHIELD 8085.

Why did you make it?

First, I have been building SBC's with old microprocessors since high school. For every SBC, I had to spend time wire-wrapping the ROM, RAM, peripheral chips over and over again. Then it was more hassle to expand the SBC. I am now lazy; Arduino Mega is capable enough so I now do my wire-wrapping in software :)

Second, I wanted to give back to the retro community. So all hardware and software design files are open source.

What makes it special?

• My goal is to make a daughtercard for every 8-bit microprocessor out there. so far I built six (6502, 6809, z80, 8031, 8085, 1802).
• I got chips for 4004, 4040, 8008, 8080, 8088, 2650, 8X300, 6800, 6803, 68008, F8, SC/MP, 6100, etc. So these are in the pipeline.