Category Archives: WonderSwan Flash Cart

Wonderswan Flash Masta Cartridges Back In Stock – Shipping Internationally!

We have just listed a new batch of WS Flash Masta cartridges! These have been very popular, and they sell out quickly when we list them. This time we have tried to make a larger batch, so I hope that those of you that have been emailing me asking for one will get one this round!

I know that some of you are wanting to purchase a Wonderswan flash cart AND a Neo Geo Pocket flash cart. As an added incentive, we’ll give you $10 off if you purchase them together! To get $10 off of your order when you purchase a Neo Pocket Flash Masta WITH your WS Flash Masta, please use the following coupon.

Coupon Code: FM_WS_PLUS_NGPC_10

IMAGE: Batch Of Wonderswan Flash Masta Cartridges
Most of these shells will have original stickers still on them. We have yet to get “WS Flash Masta” stickers produced, and we don’t want to delay cartridges just for stickers.

We are shipping these internationally! If you want to know your options and costs, please add an item to your cart and start the checkout process to see what is available for your country.

COVID had really messed up shipping for quite a while, but, at this point, I think things are starting to get back on track. If you’re purchasing a flash cart from us and having it shipped overseas, my suggestion would be to choose the First Class option. It may take about 4 weeks to arrive (depending on the destination), but the added cost of Priority Mail doesn’t seem to improve that very much at the moment. Transit times do seem to be getting better, lately, though.


We also suggest that you check out WS Flash Masta forum thread about this WS Flash Masta v5.1 cartridge if you want any further information or have questions.

Wonderswan Flash Cart v5.1 First Production Run

We have our first production run of WS Flash Masta v5.1 carts ready. Our first limited run of carts was only released for US customers. That has gone well, so we are now offering these for worldwide shipment. At the moment, we only have 30 carts available, but we will be making more.

Also, to celebrate, we are offering a coupon code to get our Wonderswan Headphone Adapter for half price when you also purchase a WS Flash Masta. Put both in your cart and then apply the following coupon.


Please read our previous post (if you haven’t already) to get a bit more info about this v5.1 Wonderswan flash cart.

WS Flash Masta v5.1 / Looking For 10 More Early Adopters

We are getting close to calling this version ready for full release. We would just like to have some more people play with it a bit before we call it good.

If you’d like to be an early adopter AND you’re in the USA, please use this button to get yours before the official release. The 10 units have been sold. We will be working to validate these units and then move on to full production (assuming things go as expected).

We are limiting this first batch to USA purchases, just in case we need to recall them. We definitely do not expect to have any problems, but we just want to limit the impact in case we do need to fix something. So far, we have a handful of these in testing, and we haven’t heard much negative, yet.

Don’t forget to add a Wonderswan headphone adapter to your order, if you need one.

If you are interested in compatibility, so far we haven’t found anything that worked on the previous v4.4 cartridge that fails on this new v5.1. You can read a bit more about that on our WS Flash Masta v5.1 forum thread.

For users, this new v5.1 should work the same as the v4.4. It doesn’t add any new playability features. Here are the new benefits:

  • Cartridge Shell – The cartridge circuitry now fits inside of a modified WS cartridge shell.
  • Battery – The cartridge no longer relies on a battery to store savegame data, so you won’t ever need to replace a dying/leaking battery.
  • Manufacturable – The previous versions of the cartridge were troublesome to source parts for and difficult to assemble. This v5.1 version should be much easier to keep in stock, so we don’t have to trickle out tiny batches of carts sporadically and annoy people that miss the opportunity to buy.

Black Friday: Flash Masta WS Available & Discounted Neo Pocket FM

On Friday, we plan to post 50 PRESALE WonderSwan Flash Masta carts for sale. Unfortunately, I can’t automate this on the website, so it will just be posted whenever I wake up and can get online on Friday morning after a big Thankgiving Thursday. That could be around 9AM Central Time. We now have all the parts to assemble these, so once the 50 are sold, we will get to work assembling them and shipping them out.

Check on Friday morning.

We will also be offering 10% off of our Neo Pocket Flash Masta all weekend (Friday through Monday).

Happy Thanksgiving!

WS Flash Masta USB (Cartridge for WonderSwan) In Stock Now

I know that we don’t post news a whole lot, but I think that this is the news that a lot of you have been waiting for. I don’t know how many of you are waiting to hear that the WS Flash Masta cart is in stock, but I do know that there are 35 of them ready to ship (as of my posting this).

UPDATE: They have already sold out in 2 hours.

These have sold out very quickly in the past, so get one while it’s available. We do plan to make another similar-sized batch sometime in the near future, but I don’t know how soon that might be. These things end up going a LOT slower than I ever anticipate.

I am trying to list these (and post this news) at a time when our European friends can purchase them, too. Timing this is a bit tricky, since we have had people all over the world ask about them. I don’t want someone to wake up in the morning and realize that they missed it, but I’m sure that would be inevitable no matter when we post this. I’m hoping that the timing here will fit well for most people that are interested.

I feel a bit odd posting short news items, since I don’t post very often. I guess I can talk about the state of our other projects.

We continue to manufacture and sell the Neo Pocket Flash Masta cartridge. That’s something of a staple for us, now, I guess. Lately we also make those in small batches, but they are easier for us to obtain parts for and to assemble. We are low

Lately, our top projects are centered around the Freeplay Zero, Freeplay CM3, and other items associated with those handheld gaming systems. We recently made a new backlight brightness controller for them, and we’re working on another add-on board for the Freeplay CM3. Head over to if you want to check any of that stuff out.

Neo Pocket Flash Masta In Stock, WS Coming Soon

We now have 20 Neo Pocket Flash Masta units in stock and ready to ship. In the past, we have made these in larger batches, but we are also very busy with our Freeplay Zero/CM3 project (think Raspberry Pi in a GBA-style shell) lately. There isn’t really a lot to report about the NGPC flash carts other than I usually tell people to sign up for post notification emails, so when we have something in stock they will get notified.

Our other news here is that we now have all the parts in stock to make a new batch of WS Flash Masta USB cartridges. We have the parts to make 40+ of these carts, and we will be working on them this week. Even though we have the parts to build 40+ we may build/release these in smaller batches, because they do take a fair bit of effort to assemble, burn, test, etc. I don’t know when they will be ready, but I hope it will be soon.

If you want one of these WonderSwan cartridges, please sign up for post notification emails at We do not keep a waiting list, so this is our main way to get the word out when there are some ready for purchase.

WS Flash Masta In Stock Now

Christmas Batch Of WS Flash Masta Carts

We have a very limited supply of WS Flash Masta cartridges. I really thought we wouldn’t get any of these built until the new year. Andrew saw all the interest in WS carts thanks to your commenting on our recent posts, so he took it upon himself to solder up as many as he could.

The batch we were able to make is only 11 cartridges. I know that people have been waiting for these, but I honestly don’t know how long they will last.

Update: WOW, those sold out very quickly. I expected them to go through the weekend. Thanks for all the interest. This just shows that we need to make more again, soon.

So, here is our Christmas gift to you. Of course it’s not free like a proper present, but Andrew did go out of his way to build these this week. Merry Christmas!

We did actually bake these in our oven (a soldering reflow oven) like some how Christmas goodies get made.

As always, please read the full description of the product before you make a purchase.

P.S. I know that in our previous post “Tell Your Friends, 10% Off For The Holidays” we gave out a 10% off coupon code for the Neo Pocket Flash Masta. Unfortunately, we can’t extend that offer to the WS Flash Masta Cartridges, because this is such a small batch.

Tell Your Friends, 10% Off For The Holidays

Our “Cyber Week” promotion went well, and we have been getting into the holiday spirit lately, so we decided to run a holiday promotion for the rest of the year (through new years day). We currently have the Neo Pocket Flash Masta cartridges ready to ship.

This is a 10% off coupon that you can apply at checkout for ten percent off your Neo Pocket Flash Masta order.


I know that many of you have been asking about the WonderSwan carts lately. We are working on another small batch (10-15 cartridges) of WS Flash Masta carts, but they do take quite a bit more effort than the Neo Pocket Flash Masta carts take. I’m sorry to say that my guess is that we won’t have enough time to get them made before the new year, but there’s a chance.

In other news, our Freeplay Zero DIY Kits are currently in stock, and the circuit boards for our Freeplay CM3 DIY Kits are being shipped to us soon. That project is taking the vast majority of our time lately, because we have Kickstarter (and other presale) backers waiting for their rewards.

We really appreciate all of you that follow along here. We’d like to wish you a Merry Christmas and/or just a great holiday season.

Flash Masta Now Open Source Software

The Flash Masta Desktop application is now open source. This is the desktop application that is used to interface with the Neo Pocket Flash Masta and WS Flash Masta cartridges via USB.

I just feel like I don’t have the time to properly maintain this code any longer, so it should finally be released to the community. It should easily compile under Windows, macOS, and Linux. This is the source code to the application found on our downloads page, and it has been released under the GNU General Public License v3.0.

To celebrate this momentous occasion, we are offering 10% off of Neo Pocket Flash Masta cartridge orders for the next 10 days. Just use coupon code open-source-10 (expired) to get your cheap flash cartridge. As always, we would love it if you would share this news on Twitter, FB, forums, etc. Let us know if you do. The coupon should be good through the end of March.

You can find the source code here, on GitHub.

WS Flash Masta Finally Available PLUS Announcing Game Pie Advance

WS Flash Masta GreenWow. I really can’t believe that it’s been so long since I’ve posted an article here. I’ve been crazy busy. I’m currently working on several projects, and I have 2 to discuss here today.

First of all, the WS Flash Masta cart is finally available on the site. I just put up a page for it. I hope people still remember about this project. 😉 If you want one, please read the product description before ordering. The project is going quite well, but I want you to know exactly what you’re getting before you make a purchase.

Game Pie Advance (spinning)Next, I want to show off another handheld retro gaming project we’re working on. Yeah, I know it looks like a Nintendo Game Boy Advance. That’s because it’s living inside of a GBA shell, but it’s a full-blown Linux machine running RetroPie. We are calling it the Game Pie Advance.

We are making a custom circuit board that fits inside of the GBA shell (making use of the original buttons) and integrates with a backlit LCD to bring you a handheld retrogaming extravaganza. No, I don’t really know what that means, but I thought it sounded cool. I may have more details here or at in the near future. For the short term, the plan is to build up 5 working units and auction them off on eBay to cover some of our costs and gauge interest. So far, we have 1 built and working. I’ll leave you with a video of that one.

UPDATE: I listed the first built on eBay.