MAG-85: An 8085 CPU Microprocessor Project

The MAG-85 8085 based computer project

The MAG-85.

Not an SDK-85, but smaller, lighter, faster, and a Super Genius.




Build a small computer system in the spirit of the SDK-85, COSMAC Elf, and KIM-1.

8085 Microprocessor Reference Card
Get my 8085 Microprocessor Reference Card! Extended instruction set, timing, electrical, and interrupt information.

A Full Computer that You Can Build:

With just 12 ICs (or 10, if you prefer) you can build a complete computer system. I had to design mine, but you can just put yours together.

You can build it on solderless breadboards, or hand-wire it up on a prototyping card. I've done it both ways.

It's got an 8085 CPU, the great-grandaddy of our present PC CPUs. It uses 8K of memory, plenty to do a LOT, but easily expandable to 64K if you want more. There's an LCD display, a hexadecimal keyboard with four function keys, 16 user inputs and outputs, and serial I/O...with 12 ICs. If you only need 8 user inputs and outputs, you can use 10 ICs to build the system.


If you want the quick and dirty, check out my blog entries on this project:


March 18, 2010 8085 Microprocessor Project: MAG-85

November 24, 2009 8085 Permanent Hardware Free Run Test

November 11, 2009: 8085 Project Update

October 13, 2009: 8085 Hardware Prototype Complete

September 28, 2009: 8085 Trainer Project

August 30, 2009: 8085 SDK Homebrew-Style

January 16, 2012: 8085 Resurgent: Back to the MAG-85

July 19, 2012: 8085 Monitor Code and Other Distractions

Build It:

Step by Step construction, just as I did it:

The Idea:

What was I thinking when I decided to do this?

Find out what this thing was built to do.