Dreamcast official documentation
From Sega Retro
EU style guide
Dreamcast Hardware Specification Outline
Dreamcast Dev.Box System Architecture
Accessing PowerVR2DC Features Under Windows CE
Software Creation Standards
How to change interrupt registers with Holly H/W
Notes concerning Drawing System Registers / Notes and restrictions on Drawing System Registers / CLX BUG LIST / TV Sync Setting List
CPU access / DMA access
Restrictions on CPU use
GD-ROM Format Basic Specifications
GD-ROM Format Specification Details