Genesis Advanced UV 1-1

Genesis / Mega Drive Advanced Flash Cart

This is a Sega Genesis/Mega Drive cartridge circuit board design that is capable of being flashed via the Open Source Cart Reader (OSCR) by sanni. Alternatively, you can also flash the ROM chips before soldering them to the board through the use of a programmer like the T48 programmer with the TSOP48 adapter. This cartridge is made entirely from brand new off the shelf components. No donors are required, and you don't need to rely on AliExpress or eBay for parts!

This cartridge covers over 95% of the entire Genesis library. You can backup games up to 4 MB in size, with up to 32 KB RAM. It can also handle any ROM hack that falls into these limits, including the ever popular Sonic 3 Complete. Check out the Game Compatibility page in the wiki for more info.

All gerbers and source files can be found in this repo, as this project is fully open source. Please read all instructions before attempting the project.

Pending Version Update

Currently, v1.2 is available for download. It should operate exactly the same as v1.1, but I have not personally verified the new design yet as I have not ordered boards to try them out. The change to v1.2 is to allow these boards to be flashed with the OSCR as 32X cartridges, but they will still be usable as regular Genesis/Mega Drive cartridges! No new components have been added, it only needed a simple rewiring of an unused portion of U3.

I do not own a 32X to test this feature out, so if you would like to test out v1.2 for me with a 32X, feel free and let me know your results. Once I verify that my changes do not affect Genesis/Mega Drive compatibility (and they should not!) I will fully update everything here to assume v1.2 is the default version going forward.

For now, v1.1 is perfectly acceptable for Genesis/Mega Drive games.

Important Things Before You Start

1. Please review the wiki for more information about using the circuit boards, instructions for how to program them, and example builds.
2. When soldering parts on, it's a good idea to put kapton tape or otherwise cover the bottom cartridge edge. You do not want to get solder on the cartridge contacts.
3. I am not responsible for any damage you do to your self or your property. Attempt this project at your own risk.
4. I do not guarantee design compatibility. You may encounter issues with certain games. There is also a chance I have made an error in the design or the BOM - if this is the case, I will do everything I can to address the problem as quickly as possible.
5. If you are using this board to make games other than for personal use, you must have permission from the originator to use and distribute any ROM images or other related material. You are responsible for making sure you adhere to any license requirements.

DO NOT use my circuit boards for profiting from stolen work - this especially includes homebrew content, ROM hacks, and using fan-made labels without permission from the originator. Support ALL original creators!

Board Characteristics and Order Information

The zipped folder contains all the gerber files for this board. The following options must be chosen when ordering boards for yourself.

• Thickness: 1.6mm
• Surface Finish: ENIG
• Gold Fingers: Yes, 30° chamfer

You can use the zipped folder at any board fabricator you like. You may also buy the board from PCBWay using this link (disclosure: I receive 10% of the sale value to go towards future PCB orders of my own):

Purchase from My Website

You can purchase this circuit board at my website, https://mousebitelabs.store. Click the following image to be directed to the specific item listing:

Purchase from Etsy

I also offer the board on Etsy, if you would rather purchase through there - click the banner to be redirected.

Purchase from OSH Park

This board can also be ordered from OSH Park, but you should sand down the edges of the cartridge to chamfer them yourself before inserting them in a console.

Here is the OSH Park page for the untested v1.2 boards.

(Image taken from RetroRGB)

Required Equipment

• You will need basic tools, like a soldering iron, hot plate, and/or hot air rework station.
• You need a way to program the ROM chip(s).
  • This can be done with the OSCR to load the game and save data onto the catridge, after the cartridge is assembled.
  • Alternatively, the T48 programmer with the TSOP48 adapter can program the ROM chip(s). The downside to this is that if you screw up the programming, you'll have to desolder the chips and program them again.

How to Program

Please check out the wiki pages on how to prepare the ROM and program the cartridge.

• Using the OSCR
• Using the T48

Board Configurations

You may not need every single part on this board to make a game. The game you want to make is mainly dependent on the ROM size and the RAM size (if any). Depending on your needs, you only need to solder on certain components, which you can find below in the BOM section.

• Every board needs Group A components. You can make games that have no RAM and are up to 2 MB large with this configuration.
• If you want to expand the ROM space to a full 4 MB, add Group B components.
• If you need RAM space, add Group C components. This will add 32 KB of RAM space.
• If your game is larger than 2 MB and uses any amount of SRAM, add Group D components.

Check out the wiki for visual examples. If you want to have a fully functional board that you can configure for nearly every Genesis game, then populate all components (LEDs optional) and use the SPDT switch for SW1.

Bypass Solder Jumpers

If your game is only 2 MB large, you will not need U3. There is a solder jumper inside the U3 footprint that needs to be bridged if this is the case.

Similarly, if your game does not use SRAM, you will not need U7 but you need to bridge the solder jumper instead.

ROM Size Selection (SW1)

There is only one switch on this board for configuration purposes, and the setting you need to choose is pretty self-explanatory - keep in mind, this is the size of the ROM file, not the amount of ROM space you have available on the board. If you have both U1 and U2 populated, for example, but your ROM file is only 2 MB, you need to configure the board to the "less than or equal to 2 MB" setting.

You can either use an SPDT switch (part number shown in BOM below), or if you do not plan to reflash the board with a differently sized game in the future, you can hard-wire the selection. This switch is only required to be configured if your board uses any amount of SRAM - ROM-only boards do not utilize this setting.

In the image below, the "less than or equal to 2MB" option is selected in both cases. The resistor on the right is a zero-ohm jumper (or you can use a solder blob).

Estimating Battery Life

To accurately estimate the battery life, you must first solder the battery in, and then either program your game in the OSCR or power it on in a console.

After that, measure the voltage across R1 (either on the part itself or on the + and - pads on the back of the board) using a multimeter in DC mV mode, touching the probes to the two test point pads on either side of R1. You should read something around 1 mV or less. If you are severely higher than 1 mV, like in the 10's of mV, then you have a problem on your board.

Once you have a suitable voltage, find the milliamp-hour rating of your selected battery (preferrably from a datasheet). For example, a Renata CR2032 battery is rated for 225 mAh.

Now to estimate battery life, take the voltage measurement in mV and the battery rating in mAh, and plug it into this equation:

Time (years) = Resistance of R1 (ohms) * Battery capacity (mAh) / Voltage (mV) / 8760

The factor of 8760 is for converting years to hours (24 hours in a day, 365 days in a year). The resistance of R1 is 1000 ohms. So for an example, if you measured 1 mV on R1 and are using a Renata CR2032, you would get 1000 * 225 / 1 / 8760 = 25.7 years.

Bill of Materials (BOM)

The component groups required for the build you want to make are detailed above.

Mouser Shopping Cart

The following cart has the maximum amount of parts you would potentially need on a single board, plus a few extras of the passive components due to price breaks. You can remove the chips you don't need from the shopping cart before ordering, according to the component group assignments below.

https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=ea748d2d57

Group A - 2 MB ROM, No RAM

Group B - Adds 2 MB of ROM

Group C - Adds 32 KB of RAM for games with 2 MB of ROM or less in size

Group D - Adds capability for larger games to utilize RAM

Note: SW1 is optional and can be replaced with solder bridges or zero ohm resistors.

Adding LEDs

There are 10 spots around the border of the board on the front and back for LEDs. This includes pads for an 0603 size resistor and 0603 size LED, powered by the 5V rail. Resistor and LED selection will vary based on your own preferences, so you will have to experiment with values yourself.

LED fix for v1.0

Four of the current limiting resistors for the LEDs are missing a connection to +5V on the board. Luckily, mirrored on the very opposite side of the board, there is a +5V point for each of the four resistors. You can use short jumpers to connect the front resistors to the back resistors in the following locations to make the LEDs light up:

Revision History

v1.2

• Added compatibility for flashing 32X games via the OSCR

v1.1 - Release

• Fix LED resistor connections on the back of the board
• Added test points for measuring battery current easier

v1.0 - Alpha

• Prototype version

Acknowledgements

• Huge thanks to sanni for firstly creating the OSCR, and secondly for adding programming support for the cartridges.
• Additionally huge thanks to agi from the discord community for his work on adding flash support for these boards to the OSCR! You have made this cartridge so much better through your hard work.
• ANOTHER thanks to agi for figuring out 32X compatibility required for v1.2.
• Continual thanks to all in the nesdev community for their resources, design tips, and support throughout the past half-decade.

License

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. You are able to copy and redistribute the material in any medium or format, as well as remix, transform, or build upon the material for any purpose (even commercial) - but you must give appropriate credit, provide a link to the license, and indicate if any changes were made.

©MouseBiteLabs 2025