This project has been a long time coming. about a few years ago I got into custom cartridges for the Game boy system. I found the information online needed to modify an existing cartridge to use as a burner cart. This worked great, but I could only fit 512kb games on it. So i decided to make my own.
I had found someone who had actually reverse engineered the little black bock known as the MBC, the memory bank controller. He had used a Xilinx 9500 series CPLD for the task. Of course I could not find the code one the internet, so I got in contact with him and he pointed me to where i could find his source code.
needless to say, when a datasheet says 5V tolerant, it does not always mean the power supply.. so that card was bust.
about last year I started DV2 of the cartridge, between work and family I finally got it done, the parts have been ordered for almost 6 months, and I only had 5 more IO lines to route. But I lacked the motivation to finish the board.
Seeing a few cartridges pop up here and there finally gave me the motivation to finish the design. The schematics have been scrubbed, really now I need to go through pin by pin and make sure everything is where it needs to be.
The basic features (planned) for the card:
- USB interface via ATSAMD21E cortex M0+
- Direct write to the header via USB (serial) should be plenty fast.
- USB programming for on board flash (32Mbit) can support 64Mbit
- 1Mbyte NVRAM for saves, no battery required.
- probably more but I can't remember at this point.
The SAMD21E is actually compatible with MatterTech's (usb) Arduino bootloader so in theory this cartridge could be Arduino compatible.
I will post schematics etc, when I feel they are ready for public consumption. I need to clean them up a bit.