Downloading firmware files like dc-flash.bin is a legal gray area because they are copyrighted by Sega.
A quick Google search for "dc-flash.bin dreamcast download" is a minefield. Here is what you are likely to encounter: dc-flash.bin dreamcast download
If you choose to download it from "abandonware" or BIOS repositories, ensure the file size is exactly 128 KB . Files of different sizes are likely corrupt or incorrect. Common File Pairing Downloading firmware files like dc-flash
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