The Dreamcast has a serial interface on the back of the console used for several peripherals and for console debugging.
A SCIF loopback connection can be created to allow a Dreamcast to conduct and pass the SCIF test on the official Sega DC Checker diagnostics software by connecting pin 4 (RX2) to pin 5 (TXD) and connecting pin 6 (RTS) to pin 7 (CTS).
This page is a stub page. It needs to be expanded with more detail. If you know more information about this topic, please sign up and contribute to dreamcast.wiki!