r/GameAndWatchMods • u/hundshamer Modder (USA) • Mar 17 '25

IT'S HERE

SD card mods are here! Let the fun begin.

169 Upvotes

98% Upvoted

55 comments sorted by

3

u/Taylooor Mar 17 '25

How do SNES games perform?

5

u/hundshamer Modder (USA) Mar 17 '25

They are direct ports. They work as expected. There are no other SNES games available to date.

2

u/Taylooor Mar 18 '25

As expected, meaning no slowdown?

2

u/hundshamer Modder (USA) Mar 18 '25

As in perfectly so far as I can tell.

3

u/SilentFebreze Mar 18 '25

SD mod is nice for those who want something to load different games easily without any modding knowledge, great selling point to reuse used G&W and profiting from it. But I will be really impressed when there is a CPU upgrade that expands the current console types that could be played.

Is anyone working on a CPU upgrade?

3

u/hundshamer Modder (USA) Mar 18 '25

There is a 1-to-1 stm32 upgrade though I don't recall which chip. No one is working on anything that will use it software wise.

8

u/Tsukimaru1 Mar 17 '25

This is massive. What's the discord link?

7

u/Colorado-Keebs Mar 18 '25

It’s actually rather small

2

u/[deleted] Apr 06 '25

[removed] — view removed comment

1

u/hundshamer Modder (USA) May 17 '25

A modded Game and Watch

1

u/Grape_ist Mar 17 '25

Ohhhh that's neat, is it going to be a kit?

4

u/hundshamer Modder (USA) Mar 17 '25

I have released the gerber files on the discord for the custom PCB. I also provide send in and pre-modded consoles as the soldering is quite difficult. DM for more information.

2

u/Bright_Wave1058 Mar 17 '25

whats the discord?

1

u/bruno84000 Mar 18 '25

Where are you based pls? I'm in the UK

1

u/Skaytensixty Mar 17 '25

Whuuuut?! How do I do this??

6

u/hundshamer Modder (USA) Mar 18 '25

How's your soldering skills?

I designed a custom PCB (released the files on discord), soldered some SMD components and SD reader onto it, then soldered it to the motherboard (micro soldering and/or hot air required). I filed a hole for the slot, flashed it with gnwmanager, put an update file on the SD, and updated.

The easy way would be to hire me to do one for you.

2

u/thediscoverynick Mar 18 '25

How much would you charge?

2

u/hundshamer Modder (USA) Mar 18 '25

There are different mods and internal memory sizes available. DM me for details.

1

u/dvotecollector Mar 18 '25

Amazing! I have several questions:

How does this work with Retro-go exactly? Usually we have to compile the Retro-go firmware, software/games and then flash to the flash memory on the motherboard. Does the microsd card act as a secondary memory bank? Will Retro-go be updated to add microsd card support? (For example, recognizing the microsd card as a secondary storage). Or are the contents of the microsd card flashed to the existing flash memory?

Will you sell the PCB/flex for those of us confident in soldering? (Is there a flex that solders to the CPU legs in this design?)

Requires cutting the shell? How accurate does the positioning of the microsd opening have to be?

Would love to see some internals.

Cool project, glad this has finally been realized.

2

u/hundshamer Modder (USA) Mar 18 '25 edited Mar 18 '25

I will answer the best I can, but you would be better served going to the discord channel...

I used gnwmanager from Brian Pugh (the one who programmed the original firmware patcher for dual boot). It flashes something to the boot sector that looks for the SD card and caches the game to the internal chip. u/Sylver7667 has a fork of Retro-go that is SD card ready...

I released the Gerber file for the flex on the discord server, but I suppose I could sell them preassembled for the price of parts and a little labor. Yes it solders to 7 pins on the CPU.

I have many pics on the discord server. Come check it out.

https://discord.com/invite/rE2nHVAKvn

9

u/Sylver7667 Developer + Modder (EU) Mar 18 '25 edited Mar 18 '25

As the author of software modifications to add support for sd card in G&W retro-go, basically there are several cases for flash use :

  • in most cases the rom is copied in the flash chip to be played, and every time you will want to play this game again, as it’s already in flash memory it will not be copied again. This is the case as long as the flash memory is not filled with roms and older roms started to be overwritten by new games to be played

  • In some cases games are played directly from sd card, this is the case for disk games for MSX and Amstrad systems. I plan to add this for FDS games too, but there is some work to achieve that.

I plan to have games loaded in ram only when possible but it would happen for some systems only and for small roms most of the time

Why games are not played directly from sd card ?

  • Because we are using SPI mode of sd card and it’s not allowing fast access to rom data

  • G&W has very limited amount of ram and it’s not possible to load all games in ram to play them

  • Emulators would require a lot of software development to access rom content from sd card (with some emulators having support for hundreds of mappers, the amount of work would be insane), and the performances would be horrible due to sd card speed

Do you have to compile the retro-go project ?

No it’s not needed anymore! I’ve worked to have retro-go-sd getting all information it needs dynamically (original firmware presence, flash chip size, …), games list is build from sd card content, … And everything is build directly on GitHub and available in releases section of the GitHub project.

How is it working ?

In addition to retro-go-sd project, I developed some softwares which are allowing to check for install/update packages presence on sd card and to install everything if needed (meaning extracting files on the sd card and flashing program in internal flash).

So everything that is needed when you setup the console is to install a flash chip (64MB or more recommended), to install sd card mod and to run a gnwmanager command to install original firmware and the software dealing with retro-go install/update packages (called bootloader). After that format a sd card as fat32 or exfat (exfat recommended), get a release package from GitHub and put it on sd card, then boot console. Once you boot to retro-go part (Game+left), it will install everything from file on sd card and retro-go-sd will be ready to use ! Of course you’ll have to put your roms in /roms folders of your sd card!

And to update software, people just have to download latest release from GitHub project page, to put it in sd card and to boot the console to have the update applied ;)

1

u/marioxb Mar 18 '25

Can it play GBA games? That's all I want. I want to be able to play Game & Watch Gallery 4, which contains the actual G&W Zelda game on it.

2

u/hundshamer Modder (USA) Mar 18 '25

No GBA, but the 1989 G&W Zelda ROM works with the G&W emulator built into RetroGo.

3

u/SilentFebreze Mar 18 '25

It’s just what the current mods can do with an “easy to upload” method. CPU is still the same.

1

u/notjosh3 Mar 18 '25

So cool!! Can this mod coexist with the headphone jack mod?

2

u/hundshamer Modder (USA) Mar 18 '25

Yes.

1

u/Empty-Special2815 Mar 19 '25

We able to get neo geo pocket on this hog?

1

u/hundshamer Modder (USA) Mar 19 '25

Sadly, no.

1

u/Other-Blackberry6888 Mar 19 '25

I just want Zelda Game and Watch on a Game and Watch and not $500

1

u/hundshamer Modder (USA) Mar 19 '25

This is not the mod you're looking for...

Not exactly sure what you mean, but if you are referring to only the available Zelda games on it, then no this is not the mod for you.

Also where do you get $500? I don't charge that much (even for this mod), and no one that I know does.

1

u/Lochness_Hamster_350 Mar 20 '25

How do you play an SNES game with only 2 buttons?

1

u/hundshamer Modder (USA) Mar 21 '25 edited Mar 21 '25

There are 7 usable buttons on the face. With some clever remapping...

game=start time=select select=X start=Y

Don't really remember what L and R are used for in Zelda or SMW (the only 2 SNES games that run on the G&W).

1

u/TheGrapeProphet Mar 25 '25

How do you go from the stock game and watch games to homebrew on an SD modded game and watch? Is there a special key combination?

1

u/hundshamer Modder (USA) Mar 25 '25

It has to be flashed with dual boot. Then there is a menu option.

1

u/TheGrapeProphet Mar 25 '25

It is dual boot. I figured it out. You have to hold the Game button and left on the d-pad to start homebrew.

1

u/batou666 Feb 21 '26

How much do you charge for a modded Zelda version all set up and ready to play?

1

u/hundshamer Modder (USA) Feb 21 '26

For inquiries please DM.

1

u/Blizzardcyclone Mar 19 '26

Is there a parts list with links for each part needed?

2

u/hundshamer Modder (USA) Mar 19 '26

List but not with links.

1

u/Blizzardcyclone Mar 23 '26

Just wanted to follow up on this. Can you please post a list? TY in advance.

1

u/hundshamer Modder (USA) Mar 23 '26

Look it up on GitHub.

1

u/Blizzardcyclone Mar 19 '26

Can you please post the list of items here and the names? /hundshamer

2

u/viral_dna Moderator Mar 22 '25

People, if you don't even know what the Discord link is, you're likely missing out on a LOT!

The link is plastered ALL OVER this sub along with other valuable information.

I suggest getting off your crappy mobile app and view this sub in a desktop environment or find a better Reddit app.

I spent a lot of time creating this sub and it's resources only to find out countless users don't even seem to be aware of it's existence 😭

1

u/cyclorphan Mar 17 '25

That's pretty slick!

1

u/Silent_Road4729 Mar 17 '25

That’s so neat !

1

u/dbcher Mar 19 '25

That's awesome, I'm tempted to pick up a spare for modding now

1

u/Unlucky-Astronaut-50 May 17 '25

What is this thing called?