The x86 protection model is notoriously complex, with four privilege rings, segmentation, paging, call gates, task switches, and virtual 8086 mode. What's interesting from a hardware perspective is how the 386 manages this complexity on a 275,000-transistor budget. The 386 employs a variety of techniques to implement protection: a dedicated PLA for protection checking, a hardware state machine for page table walks, segment and paging caches, and microcode for everything else.
为什么要两盏灯？ 这是一种低成本的“补光”技巧，防止物体背光面死黑一片，让立体感更强。
，详情可参考91视频
Цены на нефть взлетели до максимума за полгода17:55
Col. Mike Fincke, pilot of the four-member SpaceX Crew-11, said in a statement released through NASA on Wednesday that he's "doing very well" and continuing the standard rehabilitation all astronauts undergo following their missions.