Category Archives: Electronic

Oric Schematic Issue 7

Yes, nearly 1 year after the release of the Issue 6.1, I finally made the Issue 7 that would fix the VSYNC problem the previous release had!

What’s new in the Issue 7:

  • There is now a 2 pin header to plug a reset button
  • The hardware VSYNC should now work correctly
  • One of the two ROM socket has been removed to reduce the schematic complexity, but it is now possible to use the original ROM, or any EPROM without the need to change anything on the PCB, because the /ROMDIS signal has been changed!
  • Better, it is now possible, and easily to use a 32K EPROM with the addition of a switch (there are pin on the PCB for this) to select the memory bank.

Continue reading Oric Schematic Issue 7

WonderMadeleine code release

Ahoy WonderSwan users, developers and hackers!

The WonderMadeleine HDL code is available on the treasure island of GitHub. That’s some treasure chest you’ve got there.

(sorry for the pirate speak ;))

So yes the HDL code for WonderMadeleine is now available, to fit in the Altera EPM240T100C3 MAX II CPLD (a TQFP100 CPLD so not too big and easy to solder)

There is currently no support for external EEPROM, RTC of GPIO, but they will come shortly, I need to finish the documentation on how to access them from the IO port as current documentation is merely wrong. I’ll also publish a more correct hardware documentation at the same time.

This HDL code is currently licensed with the CC BY-ND-NC 4.0 license, that mean that

  • You cannot take CPLDs, burn them and sell them
  • But you can create your own cart and use the CPLD burn with the code, and you can sell the game cart you made using this CPLD (as you are not making profit from the CPLD, but from your game)
  • I’m currently not fond in allowing fork of this project until it is fully finished, but I will be really happy for patch proposal for supporting another CPLD or correcting bugs
  • And you can’t integrated this code in a larger project. that mean that you can’t integrate it with other HDL code in a bigger CPLD or FPGA.

Some of this limitation may change in a near future, but they are applicable at the time this line as been written.

I may provide in a near future a template board, either only the borders for a board that fit in existing cartridge, or even a basic board with the Bandai, Flash ROM, SRAM and save battery, depending on people’s need.

I hope that this project will help the WonderSwan homebrew scene grows as it deserve it. This game console is just an unknown jewel.

Finally…

Ten years ago, two student from the Cornell University (North Australia) released the first public homebrew cart and software for the WonderSwan that does not use the WonderWitch. See here.

Their project was a major breakthrough as they where the first to document the WonderSwan hardware, and they are the original authors of the well known wstech document.

And after they made their release… nothing more. There were no concrete or public hardware development for the WonderSwan that went to a releasable product.

Until today!

Continue reading Finally…