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The PPU (Picture Processing Unit), more specifically known as Ricoh RP2C02 (NTSC version) / RP2C07 (PAL version), is the microprocessor in the Nintendo Entertainment System responsible for generating video signals from graphic data stored in memory. The chip is known for its effective use of memory, using very little memory to store graphical data. It was rather advanced for its time when the Famicom (Japanese version of the Nintendo Entertainment System) was released, sporting full sprite support, movable backgrounds, and many colors on screen at the same time. To compete with other video game systems, like the graphically superior Sega Master System, Nintendo also extended the PPU's technical capabilities through the use of mappers, which were placed on the game cartridge. The mappers added more memory or could bank switch data into the PPU's address space, making it possible to create more advanced graphics, using more colors and bigger tile sets. == Key features == * 2 kB of external RAM to store tile layout and auxiliary color information for background graphics (commonly referred to as ''nametables'') * 256 bytes of internal DRAM for sprite attribute storage. This is measured in the amount of address space consumed; not every bit of every byte exists in the PPU. * 32 bytes of internal SRAM for palette storage. As for sprite attribute storage, not all bits exist in the PPU. * 8 × 8 or 8 × 16 (selectable) sized sprites * Two external 4 kB tile sets with space for 256 tiles each, usually stored in either RAM or ROM on the game cartridge * Up to 64 sprites (movable objects) on screen simultaneously (only 8 visible per scan line) * 25 colors simultaneously (although more colors are possible using programming tricks) from a hardware color palette of 64 colors * Picture resolution of 256 × 240 pixels (fully visible on PAL, but cropped to on most NTSC television sets) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Picture Processing Unit」の詳細全文を読む スポンサード リンク
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