Technically, dc_boot.bin is a "loader." Without it, the hardware has no logic to read a disc or display an image. In the emulation scene, needing this file is non-negotiable; it effectively acts as the digital soul of the console.
This is where confusion often begins. "DC Boot.bin" is frequently a misnomer or a renamed version of the dc_boot.bin BIOS file. However, in the homebrew and "MIL-CD" scene, has a different meaning. Dreamcast Bios Dc boot Bin Dc flash Bin
A: No. You will get a "Disc is not suitable for this system" error. You need a region-free BIOS or a boot disc. Technically, dc_boot