How PlayStation 2 Works: Architecture Overview

Core Components

Input

• DualShock 2: analog sticks, pressure-sensitive face buttons, vibration
• Peripherals: EyeToy, keyboard, mouse, mic, Network Adapter, HDD (fat PS2)

Processing

• Emotion Engine (CPU): 294 MHz MIPS-III, 2 VPUs (vector units) for geometry/physics
• Graphics Synthesizer (GS): 147 MHz, 4 MB eDRAM — rasterizer, alpha blending, no pixel shaders
• Memory: 32 MB RDRAM (main), 4 MB eDRAM (GS), 2 MB IOP RAM

Media & Output

• DVD-ROM (4.7 GB single / 8.5 GB dual layer) — game + movie playback
• Video: Composite, S-Video, Component (YPbPr), RGB SCART, VESA (progressive)
• Audio: Stereo AV, Optical (DTS/Dolby Digital), i.LINK (FireWire)

Boot & Execution Flow

1. Power on → BIOS loads from ROM
2. Disc authentication (wobble groove check)
3. Executable (ELF) loaded to EE RAM
4. EE runs game logic → sends display lists to GS via VIF
5. GS renders frame → video encoder → TV
6. IOP (PS1 CPU) handles I/O: controllers, memory cards, USB, network, DVD

Notable Capabilities

• PS1 backward compatibility (IOP becomes main CPU)
• Network Adapter (NAS) → online play, HDD install (FFXI, SOCOM)
• Linux kit (official, Japan/US) — homebrew precursor
• 155M units sold — vast library, diverse middleware

The PS2's unique VPU architecture made porting hard but enabled effects impossible on GameCube/Xbox. Its longevity stems from developer mastery of fixed hardware.