Reviving the Zenith Z-150: A Vintage Restoration Journey
There’s something inherently magical about bringing old hardware back to life. In a world dominated by hot-swappable PCBs, wireless connectivity, and RGB overload, restoring a 1980s mechanical keyboard like the Zenith Z-150 is a deeply rewarding experience. This article is about my journey restoring one such board—not just to function, but to feel alive again.
A Forgotten Relic
The Zenith Z-150 isn’t just another vintage keyboard. It’s a solid, no-nonsense board with a beautiful layout, crisp legends, and a satisfying aesthetic. My unit features the black and golden badge and uses the XT protocol—a communication standard long abandoned.
When I first got the keyboard, it was far from pristine. The keycaps had yellowed slightly with age. The switches were intact, but the cable had been cut, and the board hadn’t been powered on in decades. Most people would have called it a relic, but I saw potential.
The XT Protocol
The Z-150 uses the XT protocol, which modern computers no longer support. This meant I couldn’t just plug it in and expect it to work. Instead, I turned to a modern microcontroller: the Elite-C V4, which supports QMK and has the hardware flexibility needed for XT restoration.
The original XT cable had five important wires: Clock, Data, Ground, VCC, and Reset. I connected these to the controller as follows:
Clock → D1
Data → D0
Reset → B7
GND → GND
VCC → VCC
Additionally, I used a 1kΩ resistor between Clock and VCC and a 4.7kΩ resistor between Data and VCC. This setup mimicked the pull-up resistors typically used in XT-to-USB converters.
Diagnosing the Dead
With power applied, I began testing each switch using a salvaged LED and a pair of wires. Most switches worked, but around nine keys didn’t respond. I feared broken traces or damaged components. I inspected the board under a bright light and scraped the solder mask near the non-working pads to check continuity.
I quickly realized that the issue wasn’t complex—it was one broken connection. A single jumper wire between two points fixed not just one key, but all the others too. It was a domino effect: a single failure had interrupted part of the matrix.
Fully Alive Again
With the connection restored, the board sprang to life. I could type again—on an original 1980s board that I had restored myself. I haven’t yet written a custom keymap for it, but I plan to. For now, the keyboard works using a hex file flashed through QMK Toolbox.
What's Next and Was it Worth it?
There's still more I want to achieve on this journey:
Building a custom keymap using QMK
Replacing the diodes with new ones
Creating a custom housing for the EliteV4 controller
Retrobright the case and keycaps using hydrogen peroxide and UV
Now, was all of it worth it? Yes! This wasn’t just about making an old keyboard work. It was about respecting the craftsmanship, solving technical puzzles, and giving new life to a forgotten piece of computing history.
If you’re thinking of restoring a vintage keyboard, I say go for it. All you need is patience and some basic tools. But the most important tool you would need is the curiosity to explore.
The click of every key now reminds me: this isn’t just a keyboard—it’s a project, a memory, and a resurrection.