Tutorial
Use Real NABU PC Computer Hardware Tutorial
Follow these steps to get a real NABU PC connected to the original 1980's NABU Network.
Introduction Of Tutorial
To use a NABU PC, we need three components that work together to recreate the original 1980s online NABU experience. In this tutorial, we’ll download, install, and configure them:
1. NABU Internet Adapter — This software emulates the original NABU cable data network. In the 1980s, NABU consoles received software over the cable TV infrastructure. The Internet Adapter replaces that system by acting like a virtual cable modem, delivering NABU programs over the internet or from local files.
2. NABU PC Computer — The NABU PC from 1980, inwhich there are only around 2,500 left in the world!
3. RS422 USB Adapter — The NABU PC connected to the cable modem with an RS422 serial protocol. To connect a real PC to the network, you will need a USB-to-RS422 adapter.
By combining these components, we can reproduce the original NABU environment: RS422 connects the NABU computer to the Internet Adapter. The Internet Adapter supplies the software and data. The following steps will walk you through setting up both.
1. Get "The Internet Adapter"
The first part of the setup is downloading the NABU Internet Adapter, which acts as a replacement for the original cable network. Instead of pulling software from the 1980s broadcast system, the emulator pulls programs from your local computer or the internet.
What it does:
* Emulates the original NABU cable modem/data stream.
* Provides the software that the NABU boots and loads.
* Lets you choose between online servers or local files.
Download Location:
You can download the latest version of the Internet Adapter by clicking the Visit Downloads button below.
*Note: There are downloadable packages for all popular operating systems. However, it is recommended to begin with the Windows versions for simplicity unless you are technically proficient with your alternative OS.
Installing:
Once you’ve downloaded The NABU Internet Adapter, extract or install it (depending on the release format), but don’t run it yet — we’ll configure it in a later step once the NABU Cable is ready.
If you are starting with the Windows version of the NABU Internet Adapter, the installer will automatically install and create a link in the Start menu.
2 The RS422 Cable
To connect a real NABU PC to modern software, we need a way to replace the original cable network signal. The NABU communicates through its HCCA port, which uses RS-422 differential signaling. This is how the original machine received its data stream from the cable system.
Since modern computers don’t have RS-422 ports, we use a USB-to-RS-422 adapter cable to bridge the two worlds. On one end, it plugs into a regular USB port on your PC. On the other hand, it provides the RS-422 transmit/receive lines required by the NABU’s HCCA interface.
What This Cable Is For:
* It carries the NABU data stream from your PC to the NABU console
* It replaces the original 1980s cable feed
* It allows the Internet Adapter software to “talk” to the real hardware
* It handles proper voltage and signaling levels for RS-422 communication
Why RS-422?
The NABU PC wasn’t designed for RS-232 or USB. RS-422 was chosen for extended cable length support, noise-resistance (differential signaling), and reliable streaming performance.
By using a USB-to-RS422 converter, we simulate the original NABU network link in a modern, safe, and reversible way.
Video Introduction
If you want a quick visual explanation before building the cable, here’s a video where DJ introduces the USB-to-RS422 connection and explains its role.
NABU Network Cable Summary
The RS422 portion of the cable must be as short as possible, or two twisted pairs if possible. Also, keep the RS-422 cable away from AC power cords. The cable should be shielded only to the GND pin of the DTech RS422 adapter.
Lastly, I advise using a twisted pair Ethernet cable. Connect the RX+ and RX- on the same twisted pair. Do the same with the TX+ and TX- on the same twisted pair.
This cable is the lifeline for your NABU, so do not chance a poor-quality effort. Some people choose to use a MIDI cable, but it won't be a twisted pair and isn't RS-422-compliant. If you are hard-set on using a MIDI cable because the 5-pin DIN connector matches the NABU, keep it short. And you won't get much love if you complain to users that the NABU keeps disconnecting *wink*. If you need a longer cable, consider extending the USB portion rather than the RS422 portion (unless it is a twisted pair).
*Note: GND should only be connected to the shield on one end. If your cable is grounded on the DTECH connector, do not connect the shield to the outer rim of the DIN connector. Why?
5 Pin DIN Pinout
This is the pinout of a 5-DIN connector from the solder side. *Note: GND should only be connected to the shield on one end. If your cable is grounded on the DTECH connector, do not connect the shield to the outer rim of the DIN connector.
RS422 Breakout
If connecting directly to the DTech RS422 adapter breakout, use this image as a reference.
RS422 DB9 Cable
If you have a DB9 cable with wire codes. Well, I'd verify the wires first, including their colors, to make it easier.
3. Setting up The NABU Internet Adapter
Now that you have the cable connected between the NABU PC and the computer, the next step is to configure how they communicate. The NABU Internet Adapter includes a built-in Serial server, which the NABU PC connects to via the USB RS422 adapter. This link simulates the original coaxial cable connection used by the physical NABU in the 1980s.
How it Works:
* The Internet Adapter runs a small Serial server on your computer
* NABU PC connects to that server over the USB RS422 connection
* Once connected, data flows from the Internet Adapter into the NABU
* This simulates the original cable distribution system used by NABU
Why This Exists:
Back in the day, NABU PCs didn’t load software from disk. Everything was transmitted over the cable TV network. By tunneling that data from the Internet Adapter instead of coax, we recreate that environment using modern tools.
With this setup, the NABU PC behaves just like a real NABU connected to a live cable feed in 1980!
What You’ll Do Next:
1) Launch the Internet Adapter by double-clicking the shortcut in the Start menu if on Windows. Otherwise, execute the binary on your preferred operating system.
2) Press the SETTINGS button to open the settings menu so we can configure the COM port.
3) Select the RS422 USB port from the list in the Serial Tab and press SAVE. The Settings window will now close.
4) On the main window, press the START SERIAL button.
That's it! The NABU Internet Adapter is now sitting, waiting, wishing for a NABU PC connection.
4. Turn On The NABU PC
With your USB-to-RS422 cable wired correctly and the Internet Adapter running on your computer, you’re ready to power up the real NABU PC and let it connect.
Before You Switch It On, make sure that:
* The Internet Adapter software is running on your computer
* It is configured to listen on the correct COM port
* The RS-422 USB adapter is plugged in and detected by your operating system
* The NABU’s HCCA cable is firmly connected between the adapter and the NABU PC
When everything is set, you’re ready for the moment of truth.
Powering Up
Flip the power switch on the NABU PC. After a brief pause, the NABU will begin sending out its startup request on the HCCA port. The Internet Adapter will detect this request and start streaming the boot data, just as the original cable network did in the 1980s.
If everything is communicating correctly, you should see the NABU’s familiar boot screen appear, followed by the RetroNET launcher once the data stream begins.
What’s Happening Behind the Scenes
* It initializes the video and keyboard hardware
* It sends a data request out the HCCA port
* The Internet Adapter replies and streams software to the NABU
* The NABU executes whatever program or channel is currently configured
From here—you’re driving real 40-year-old hardware!
5. Operating Your Emulated NABU PC
Once NABU connects to the Internet Adapter and finishes booting, you’ll land in the RetroNET Headless menu. This menu was designed to feel like a cable-style channel navigator — reflecting how the real NABU PC was initially used in the 1980s. Instead of loading software from disks, users “tuned into” programs broadcast over the cable network.
What RetroNET Headless Is:
RetroNET Headless is a launcher interface for modern NABU software. From here, you can browse and launch programs (often called “channels”) that run on the NABU PC.
What You Can Do From the RetroNET Menu:
* Run the original NABU Cycle software. Experience the same programs that real NABU users accessed decades ago.
* Read the latest NABU news feed. The community maintains a modern online news stream for active users.
* Play modern homebrew games. Developers are still creating new titles for the NABU, including action, puzzle, and retro-inspired projects.
* Load CP/M. CP/M opens up a full suite of classic computing tools, text editors, compilers, and utilities.
Exiting a NABU Program/Channel:
The NABU has physical buttons on the front case. The RESET and POWER buttons. Pressing the RESET button will exit the current program and return to the RetroNET Headless Menu.
Peripherals:
Joysticks
* The NABU uses up to 4 joysticks for multiplayer games. While most games are 2-player, there are a few 4-player games, such as BrickBattle and Game Man Yeah!. The majority of NABU keyboards have 2 joystick ports; however, some lucky O.G. NABU owners have 4.
Cameras
* There are a few applications that will use the PC camera to simulate a live video feed over the cable system to the NABU PC. If you have a webcam, some applications, such as NABUCAM or NABUCAMCOLOR, will use the webcam.
Things To Experience With NABU
There are hundreds of homebrew applications developed by the community to use, and new applications are often created. The NABU Discord is a great place to meet other NABU enthusiasts, who are also helpful to give you any assistance needed to get up and running.
Original NABU Network
The original NABU network contains a ton of applications originally published for the NABU PC in the early 1980's.
8Bit Abyss
An online multiplayer dungeon crawler... in 8bit goodness! Leverage the power of the NABU Network by connecting with others to play together online.
RetroNET Chat
Online chatting application to talk with others in real-time.
Cloud CPM (text mode)
Cloud CPM 2.2 is a text-based operating system for early microcomputers. Because the NABU PC was initially launched without local storage, the idea was to allow PCs to offload their data remotely. While Cloud CPM doesn't offload the data into the cloud, it uses the Internet Adapter to "simulate" the cloud. This is a very unique CPM that does not require local storage, and therefore offers 40 MB of CPM drives filled with programs!
Cloud CPM (gui mode)
We can't leave this out of the list, because it has to be experienced to believe! This is an entire GUI for CPM that replaces the CCP (Control Command Processor) prompt. It also allows mapping a drive between your PC and NABU to copy files! Putting files on CPM has never been easier.
Tetris
Of course a homebrew ecosystem wouldn't be complete without a copy of Tetris!
NADOOM
Can it run DOOM? DOOM on the 8bit 64k NABU? Yup! Featuring digital audio of the original soundtrack and 3d ray-casting.
Bad Apple
NABU wouldn't be able to join the 8bit retro scene if it didn't have a version of Bad Apple demo with multichannel music showing off the AY-3-8910.
Musical Slide Show
What would a 8bit retro PC be without Chip Tunes?! This slideshow has hundreds of 80s inspired images and in the background is a random selection from over 20,000 chiptune songs.
Net Muse
Sick of chip tunes? How about streaming internet digital radio - directly from your favorite source. Or, select from one of the default channels available. 80's mixes, Soma FM Groove Salad, and more....
NABU Cam
Another example that demonstrates the power of the NABU as a 1980's network PC. This application streams B&W or color from your Internet Adapter to the NABU PC.