Sega CD comes to MiSTer care of Srg320, author of the Super Nintendo Core and its special chips (CX4, DSP1-4, OBC-1, SA-1, S-DD1, SPC7110, S-RTC, ST010, Super FX/GSU), as well as Virtua Racing’s SVP chip for the Sega Genesis. The Sega CD core is very solid for a first release. All 150 official releases have been tested and work, with a short list of known-issues that will be cleared up as updates are issued.
The core supports BIN/CUE and ISO/CUE disc dumps, and the Redump Sega CD Set is plug-and-play. The BIOS I recommend is “Sega CD 2 (USA) v2.00W”. Copy it to /games/MegaCD or rename it to MegaCD.rom and place it in /bootrom
Although the Genesis core doesn’t require a RAM add-on, the Sega CD core does require at least a 32MB SDRAM add-on module.