Sega CD / Mega-CD modding wiki

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Tutorials & reference

Sega CD / Mega-CD modding, repair and homebrew

Sega CD and Mega-CD use a compatible Genesis or Mega Drive as the base console. Start by identifying both units, matching their power supplies and regional software, then establish a working original-disc baseline. Integrated CDX and Multi-Mega variants require their own documentation. This directory expands the existing Genesis articles with complete setup, storage, media and testing workflows.

Source review: October 11, 2026. Guides are original source-linked writing. Original manuals may describe a specific regional model or production revision; modern project documentation may change. Match the exact board, peripheral and firmware before following a procedure.

Begin with identification and setup, then make a preservation plan. A working startup screen is only a first test: disc reading, graphics, sound, controller modes and saving each deserve a separate check. Troubleshooting guides explain how to record a reproducible symptom before choosing an internal repair.

General information and setup

Sega CD and Mega-CD models and buying checklist — Identify the complete system, region, drive revision, missing accessories and evidence needed before buying a Sega CD or Mega-CD.
Sega CD and Mega-CD power, assembly and audio setup — Assemble a supported base console and CD expansion with matched adapters, correct mounting parts and a documented audio route.

Storage and software compatibility

Sega CD backup RAM, save cartridges and verified backups — Understand internal backup RAM, cartridge storage, modern per-game saves and a testable preservation workflow before resetting memory or repairing retention faults.
Sega CD disc regions, audio tracks and CD hardware replacements — Separate official disc compatibility, display timing and BIOS matching from modern cartridge CD emulation and 32X CD requirements.

Repairs and homebrew

Sega CD drive, boot, audio and video repair triage — Separate base-console faults, expansion connections, mechanical loading, disc reading and audio routing before selecting a revision-specific repair.
Sega CD homebrew tools and development workflow — Build and test original Sega CD software with a dedicated CD framework, official hardware references and reproducible disc images.

Use legally obtained software and BIOS files with tools that require them. A flash cartridge or emulator's feature list does not establish support for every add-on combination. Board-specific soldering, power wiring, storage conversions and optical adjustments require documentation that matches the actual hardware.

All guides

6 guides

Sega CD / Mega-CD Sega CD and Mega-CD models and buying checklist Identify the complete system, region, drive revision, missing accessories and evidence needed before buying a Sega CD or Mega-CD. Updated Oct 11, 2026 Sega CD / Mega-CD Sega CD and Mega-CD power, assembly and audio setup Assemble a supported base console and CD expansion with matched adapters, correct mounting parts and a documented audio route. Updated Oct 11, 2026 Sega CD / Mega-CD Sega CD backup RAM, save cartridges and verified backups Understand internal backup RAM, cartridge storage, modern per-game saves and a testable preservation workflow before resetting memory or repairing retenti… Updated Oct 11, 2026 Sega CD / Mega-CD Sega CD disc regions, audio tracks and CD hardware replacements Separate official disc compatibility, display timing and BIOS matching from modern cartridge CD emulation and 32X CD requirements. Updated Oct 11, 2026 Sega CD / Mega-CD Sega CD drive, boot, audio and video repair triage Separate base-console faults, expansion connections, mechanical loading, disc reading and audio routing before selecting a revision-specific repair. Updated Oct 11, 2026 Sega CD / Mega-CD Sega CD homebrew tools and development workflow Build and test original Sega CD software with a dedicated CD framework, official hardware references and reproducible disc images. Updated Oct 11, 2026