1ST READ.BIN Checker
This tool will check the main Dreamcast binary and tell you if it's a unscrambled, scrambled, ELF or SREC binary format. It also serves as a front-end to convert your files from ELF formats to binary formats. It also uses scramble by Marcus Comstedt to convert binaries to unscrambled or scrambled binaries and sh-elf-objcopy to convert ELFs into binaries.
There's also a command line version available that was written in C. There's binaries for the current version, 0.1, for Windows and Linux. The source code is also available here. For Mac users, they can compile 0.1 themselfs or use the original vb2c release binary here.