The 1970's through the 1980's were the times of magic for the personal computer.    If you could time travel back to 1976 to Crist Dr in Palo Alto, CA, you would have found a couple scruffy looking guys creating the original Apple personal computer in their garage.  Later you might be able to witness Commodore set a sales records of approximately 30 million Commodore 64s.

Ever feel like you missed out on the magic era of the personal computer because you were born too late?

Ever want to re-create your own little Z80 or 6502 based microcomputer but had your eyes start to glaze over when you realized it was going to spending weeks of soldering together dozens of obsolete IC's no guarantee that it might work at all? 

This Instructable will teach you how to build your own retro-style microcomputer to program, play games and music, and most importantly re-create some of the magic from the 1970's on your own table.   You will be able to assemble this project in an afternoon, and enjoy it for months to come.   We'll start with some a simple kit and build from there.

Edit: This is still an extremely popular project, but the parts used are no longer in production.
I've joined up with Gadget Gangster to create my own board as version 2 of this concept.
The Instructable can be found here: https://www.instructables.com/id/Build-your-own-pocket-mini-computer/

Step 1: Required: Parts & Tools

You'll need the following items for this project:


Propeller Multicore Startup Special  - This is the core of our retro-style microcomputer. Because it is a modern 32bit processor, we won't have to worry about frustration of working with dozens of obsolete (and very static sensitive!) microchips.

* RCA UltimateTV Keyoard : Part# WKB10WN1 - Other WebTV keyboards are likely as compatible, but this was the unit that was tested with this project and are commonly available on both Ebay and Amazon.

* A 38kHz Infrared (IR) Receiver Module - You can obtain this from either Radio Shack or Parallax .  I'd recommend this kit , as it will provide you a snazzy remote we can use later for basic game control.

* 3.3k resistor - From Radio Shack (or your toolbox: ORANGE, ORANGE, RED)

* A 7.5v DC (center positive) wall adapter with 2.1mm barrel connector - In a pinch any adapter ranging from 6v-9v DC will work fine.

* A microSD card w/adapter - You'll want to be able to put files on this card using your PC.


* A soldering iron or soldering station

* A roll of solder

* A pair of wire cutters

* Safety glasses

Step 2: Solder and Assemble the Top Board

The kit comes with two boards which make up the foundation for our retro-styled mirocomputer.  The first board is called the Gadget Gangster Propeller Platform USB which houses the brain of our computer, a Parallax Propeller microprocessor, as well as some EEPROM storage memory and a microSD adapter.   This board incorporates a lot of surface mounted electronics, hence it arrives assembled.

The top board called the ProtoPlus Module and can be assembled by anyone with even limited soldering skills in a few minutes.  Once assembled it will provide the audio / video and keyboard interface for our microcomputer.

Here's a quick video on how to assemble the ProtoPlus Module:

Step 3: Creating the Keyboard Interface

Creating the keyboard interface:

Up to this point, we have building pretty much a stock kit created by Gadget Gangster and Parallax for Propeller microcontroller enthusiasts.   Assembling the kit has given us audio and video out, but no way to interact with our retro-style computer.  In other words, it's not really a computer yet.

It's time to jump off the kit path and add a simple IR keyboard interface.

Grab the 3.3k resistor, the 38kHz Infrared Module, and a couple short (resistor length) pieces of wire and create the the simple circuit as seen in the first photograph.   It is important that the IR is wired correctly, so solder it together facing up to match the photograph.

Step 4: Adding the Keyboard Interface to the Top Board.

Adding the keyboard interface to the ProtoPlus board:

Now that you have wires and resistor attached to the IR module, solder them into the ProtoPlus Board as shown.
(First Photo)

After making the connections, I gave the lines a twist and let the rigidness of the wire hold things in place.
(Second Photo)


If you have the El' Jugador module (also available  at Parallax) instead of the ProtoPlus board, you will significantly increase your compatibility with existing games and demos which use the NES controllers.    Simply make the same connections to the El' Jugador with the IR as the ProtoPlus board.   Knock out the two punch outs on the case allowing the NES connections to pop through the top during the case assembly phase.

Step 5: Assemble the Case

Our retro-style computer even comes with a "retro" case!  The transparent black enclosure features etched port labels, pin-striping, and a “bowtie” design reminiscent of a 1920’s gangster.

The are step-by-step instructions here .  Generally, I've found it easy to peel off all of the protective paper, then assemble the four sides together first, then fit them together into the bottom of the case.   Be carefully not to punch out the two rounded holes in one of the case covers.  These are for use with the El' Jugador product, an upgrade you can do later.

Step 6: Starting Up Your Retro-style Microcomputer.

Software for your retro-style computer:

Congratulations!  If you have a WebTV keyboard you are ready to turn on your computer and enjoy!

I've included a few programs here to get you started. 

The first thing you'll want to do is to install an Operating System on the EEPROM memory of your microcomputer.

Download the following programs:  Propdos & Propeller Tool

The Propeller Tool Software will be installed on your Windows PC.
The PropDOS.binary file will be installed on your microcomputer.

1. Connect your new microcomputer to your PC using the supplied USB cable.  

2. Install a microSD card into the slot on the side.

3. Connect the specified power adapter and power up the unit.

4. Completely install the Propeller Tool Software and run it one time.   It will ask about associating various files, answer yes .

5. Double click on the PropDOS.binary file and click on LOAD EEPROM .  This will install the Operating System.

If you see the following:

Propeller MiniDOS V1.6
By Jeff Ledger


Then success!  You have installed the micro operating system and are ready to install programs on the SD card. There are hundreds of programs which are compatible with this machine.  I'll post them on forums @ SavageCircuits as they are ready.

(BASIC has been ported: See the forums for details.)

<p>Can you upload a video with it finished?</p>
This, my friend, is extraordinarily awesome. A little money for supplies and I am so going to build this. And then I start work on a little homebrew OS, make an interesting and neat case for it...the possibilities are endless. Thank you!
<p>I started off with computers in the 70s, used counter sorters, mainframes and right through the 80s with the first ample computer, then the compaq laptop in dose language up to the present. I would be happy to put one together and experience it. Thanks</p>
If you don't want to spend a lot of money and understand AVR microcontrollers pretty well, there this kind of thing, too -&gt; http://spritesmods.com/?art=avrcpm
since the apple2 schematics, and the os are laying around, still usable, i had thought of making one from smt's, it'd be pretty cute, modern micro connectors for cards, easily done up in eagle and banged out.
I would love to see that done! Please do post an 'ible if you get around to doing it. :)
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2143646_-1 well, a plcc 6502 is close, they have them as qfp and dip too, so at least someone could fix a broken original. personally, i'd see about switching the dynamic ram for static, or maybe a more modern dram chip.
You know, some of us were born before the 80s so we do remember playing with the actual hardware (poking 6502 machine coded directly into the apple iie monitor - oh the pain, but such good memories). Thanks for making me feel really old ;).<br><br>Another option, albeit much more advanced, is to use an FPGA. There are plenty of IP cores available for the 6502 and it's bigger cousin the 65C816. I've synthesized both successively, only now I have an actual cross compiler and tool chain so I can write an an a high level language like C and no more poking machine code into the monitor! ;D
I noticed that the code is in binary. Why not in spin? Will the code work on the propeller demo board? I would prefer to use the demo board because it already has video, keyboard and mouse plus audio and a breadboard on it. That should eliminate the need for the shield.
I appreciate the fact that you seem to be well versed with the Propeller. This article is focused more toward those with an interest in retro-computing who have had little to no exposure to the Propeller product. You'll notice that I've jumped past a lot of explanation, leaving much to be discovered after completing this simple project. I'd invite you to join us on the Propeller Powered forums / Parallax forums for more in depth Propeller discussion. -Jeff-

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