dcload-serial
dcload-serial is a homebrew program originally developed by Andrew Kieschnick, now maintained by KallistiOS developers at the dcload-serial repository. It is the sister application to dcload-ip.
It allows a developer to use a serial cable (also referred to as a "coder's cable") as a link to send, execute, and debug code on a Sega Dreamcast console. It is typically loaded via CD-R, but can also be loaded directly through the BIOS (for example, using DreamDash).
It is able to transfer .bin and .elf files (and srec files, if specially configured for it) over the serial port. It also provides chainloaded programs with a standard syscall interface for communicating with a connected PC. The program is mostly intended for homebrew development, but can also be used with special programs.
DiscJuggler images of the latest DC side software as of June 22, 2023 are available to download: DiscJuggler images of dcload-ip 2.0.1 and dcload-serial 1.0.6