Many Processors Can Do Their Own Task Switching in Hardware by Jim Turley “What fresh hell is this?” – Dorothy Parker Want a fun late-summer project? Looking for a source of frustration? Need a quick hack to polish up your programming resume? Let’s create our own RTOS using the built-in hardware features of the x86 processor family and very little code. Calling this an “RTOS” might be overselling it a bit. A real, real-time operating system will have lots of advanced features that this won’t have. This is more of a scheduler or task switcher than a fully formed operating system. Still, it’s both useful and educational. If nothing else, it highlights some of the wondrous features lurking inside every x86 processor. Features that, alas, have been unappreciated and underutilized.