RetroOnyx: Looking back at 2025

It's that time again. Time to look back at the year 2025 for RetroOnyx and summarize what has been accomplished. It's been a busy year again. I'm still working RetroOnyx in my "spare" time at night after work and on the weekends. It's a way for me to do fun design work and learn new skills. This year was about building more HyperBoy+ carts, HB+ box sets, a VB wireless controller/receiver, the surprise release of the first VB multicart MrCART, and my usual builds of Warzone, Wonderswan battery packs, and misc. cables.

HyperBoy+

The beginning of the year started with aluminum shells coming in for HyperBoy+ for a batch 2 run. Aluminum shells have turned out very well and are now my standard approach to HB+ shells. A picture of a couple variations of HB+ are shown below. The yellow color in the new BWRY eInk panels really allows more character and detail in the game labels.

Box sets for HyperBoy+ were also built this year. A single run of these was done of 50 units. Designed by VB community member Mumphy, the HB+ design is a fresh color change on the original HyperBoy box set. It's yellow to emphasize the new BWRY eInk panel and make it stand out from the crowd. It definitely won't be missed sitting on the shelf among other VB box sets.

I'm currently debating if I do another run of HB+ in 2026 so if you're interested please sign up for stock notifications on the product page. I've highlighted things I've learned on HB+ in past posts and so won't do so again here.

VB Wireless Controller PCB and Receivers

I decided to build a VB wireless controller PCB this year. I did the actual design work last December. The PCBs were built in early 2025 and it was a great project overall. It helped me learn KiCAD and how to replicate existing PCBs. I used the OEM VB controller PCB as the starting point and updated it for an ESP32 controller and future haptics support. The first version of that PCB is shown below. About 50 of those units were shipped in 2025.

KiCAD has this unique feature of allowing an image to be imported into the design that you can then scale and trace. This allowed me to get the PCB dimensions perfect and also to place the conductive pads for the buttons all in the right place. It also allowed me to trace and replicate the buttons/pads exactly like they are on the original controller board. I was inspired to do this after seeing someone else recreate the original VB controller PCB. I thought, wow, that's a great idea... what if I could make it wireless. I also designed trigger PCBs and even the trigger PCB standoffs as part of this project.

The original V1 design was intended to mate with my VB BlueRetro receivers but firmware restrictions on the BlueRetro side didn't pan out. That lead to the development of a low latency 2ms ESP-Now firmware, which is what shipped with the original V1 designs. That also meant ESP-Now specific receivers. This was a bit confusing on the customer end, I'll admit, due to the BlueRetro and ESP-Now receivers having the same physical shape and size. I even designed a V2 receiver, which has since been shelved. It may come back as a WiFi wireless link cable at some point.

Then Nintendo surprised the world and announced a Nintendo Switch Online (NSO) Virtual Boy replica accessory. To many people's surprise, it doesn't include a replica VB controller. That lead to my V2 design for my controller which runs Switch firmware and even supports haptics. The V1 design can run the Switch firmware also, but V2 makes some assembly improvements, adds haptic driver chips on the PCB, and moves things around a bit to make programming easier when mounted into the controller. All quality of life improvements. I'll be doing a run of the V2 design in early 2026 so that controllers are ready for the NSO VB release in February 2026. You can see the product page for the V2 hardware here.

I still need to design optional haptic modules that fit into the controller handles. Haptics have been tested and works much like a Switch Pro Controller. I even use the same Switch haptic module from Alpine that I also used in my VB rumble pack. Haptic modules will be a separate add on cost, or you can even buy and build them yourself to keep costs down. I'll be releasing the 3D print files needed to hold them securely within the controller body. More info to come here.

Overall, I had a great time with the wireless controller project. It allowed me to learn KiCAD, learn more ESP32, learn more details about Switch controller firmware, add haptics, work with light pipes again, and even use AI. Amazing times.

MrCART Multicart

The world's first true VB multicart was released this year to everyone's surprise. This was released by VB community member Mr. Flower. Mr. Flower actually started an earlier multicart design back in 2022 but it was never released. Little did everyone know that he continued working on a new design in secret. A surprise announcement on May 21st 2025 revealed this new design to the VB world.

Mr. Flower shipped the first 24 or so units directly with a unique box set and keychain keepsake built from the donor cart PCB, as shown below.

Mr. Flower needed some help in producing MrCART units in any sort of volume and so I reached out and worked out a deal to be the sole supplier for MrCART units. This lead to some PCB updates, SRAM memory changes, and an aluminum shell being added to the design. RetroOnyx would ship batch 1 units in the original OEM plastic shells and offer red or black aluminum shells as an option. Batch 2 and future batches will all ship with red or black aluminum shells to give it that RetroOnxy feel.

These MrCART products are the first product that RetroOnyx has distributed that wasn't designed by in house. So far it has been a great experience and I'm glad I could be apart of this first VB multicart experience. I expect to continue offering MrCART units as long as there is interest. Maybe even do a boxset in the future.

Lessons learned on MrCART are mostly regarding working with a 3rd party engineering team and it's gone as good as I could have expected. That's good news for other future potential partnerships and expanding to new products.

New VB 128Mbit Cart Up and Running

I've had a new V2 128Mbit VB cartridge PCB since 2024 but had never set the time aside to get it up and running. It's a new design that uses 3.3V parts much like any future multicart might... It has the necessary translators as you can see at the bottom of the image below just above the VB cart connector. This 128Mbit cart design has naturally 128Mbit of flash and 128k x 16 SRAM, a unique addition for VB carts. A larger SRAM and a wider bus gives VB developers more scratch pad space to work with to make more advanced VB games.

As you can see in the picture above there are some jumpers on this first spin that will be fixed in a future runs. The design has already been updated and its ready to go for any VB developer that wants larger ROM and RAM space. This cart was specifically designed initially for the VUEngine team for their upcoming Formula V game.

I still have about 10 of these prototype 128Mbit carts available if any VB developer is looking for some. You can find them here. Lessons learned on this project are the new translators, larger memory sizes, larger SRAM, and larger bus width for SRAM, as well as a continuation of my battery backed SRAM approaches. Much of this design will be present in any future multicart design I do.

Other Misc Work

I've continued as I always have in building VB link cables, VB extension cables, Warzone carts/CIBs, Dreamcast link cables, Dreamcast USB cables, and Wonderswan battery packs. Hard to believe I'm still building and shipping cables, to be honest. I'm also still shipping Virtual Boy USB-C Power Delivery (PD) power supplies. That stuff trickles in but helps fund future VB work as well. In 2025, I built all of this gear myself, as my part time helper moved on to other pastures. I proved to myself this year that the designs are still solid and that I can still do it myself.

Patreon Supporters

Many many thanks to my Patreon Supporters in 2025. Every Patreon dollars goes back to a VB project and its development. I also use it to get feedback and direction on future paths of projects. It's a valuable source of support and I salute all those that have supported me over the years. It's a passionate VB community. In 2026 I hope to give out some more free gear. Thank you for all that my supporters do!

For those of you who aren't supporting my Patreon and want to, you can find my Patreon page here.

There's also the awesome VUEngine team who are working on VB Studio and the Formula V game. You can find their Patreon here.

As well as Thunderstruck. He does more than most know and has his own Patreon here. Please support him if you can.

Looking Forward to 2026

I'll spend the first couple weeks of 2026 getting the last of MrCART batch 2 shipped out. Then I'll probably do a V2 run of the Switch VB wireless controller PCB. Then maybe a batch 3 run of MrCART, or possibly more HB+. I've been wanting to get back to eInk.

There's some work that has been done recently in VB motherboard connectors for programmers and I have 25 of them right now. I may do a V2 of my programmer to use a new generation STM32H5 processor. For those who have been following my work for a long time, all of my projects build upon themselves and have been leading up to the end game: my eInk multicart. The new V2 128Mbit cart this year tested a lot of that architecture. If I do a V2 programmer, it would allow me to play with faster updated processor portion. Very much like how my original programmer was the development kit for HyperFlash32. I'm also running out of side projects to distract me from the multicart! LOL. Just some thoughts for 2026.

Some other things that may come into play are also something with the V2 receivers I built but paused work on. That receiver has an ESP32 on board but can connect to both the VB controller port and extension/link port. It could become a wireless WiFi module or wireless link cable. TBD. Just some wild ideas that have been thrown around in the past.

If you've gotten this far then I'd like to just say thank you for sticking to it and taking the time to review RetroOnyx in 2025. I look forward to more fun projects in 2026. Happy Holidays and Happy New Year!

Kevin