Mega-CD official documentation
From Sega Retro
Mega-CD BIOS Manual
Mega-CD Disc Format Specifications
Mega-CD Hardware Manual
Mega-CD Outline
Mega-CD Hardware Manual PCM Sound Source
Mega-CD Software Development Manual
Mega-CD User Interface
Mega-CD Maintenance Manual Export Rev.A
Sega-CD Software Standards
Sega-CD Technical Bulletins
CTrac BuildDisc Reference Manual
CTrac Builder for Sega Genesis
CTrac BuildTrack
CTrac CD Emulation System
CTrac Emulator
CTrac ISOUtil
CTrac Write Once
Sanyo LC7883
Sanyo LC8950 & LC8951
Sega Service Manual - Sega CD II - Mega CD II - 002 - August 1993
Sega Service Manual Supplement - Sega CD II - Mega CD II - 002-2 - June 1994
Sega Service Manual Parts Specifications - Genesis VA7 - Mega Drive PAL VA6.5 - Mega/Sega CD - 010 - April 1994
Additional information including differences between Sony and Funai Sega CD II/Mega CD II models