modern operating system 3rd edition,1

Introduction
shell&GUI is not operating system but uses the operating system to get its work done.
the source code of Linux or Windows is five million lines.
OS serves as an abstraction of the hardware(top-down view).
OS manages the hardwares and information(bottom-up view)---multiplexing in time or space.
Windows 95/98 is 16-bit,but Windows NT/2000/XP is 32-bit
hardware:

poll(轮巡)
high-end(最高端的)
GUI of Windows is "Windows Explorer"
With UNIX,there's almost one-to-one relationship between system call and library procedure.But in Windows, the system calls are decoupled with Win32 API.And many Win32 API will not invoke system calls.
Win32 API
CreateProcess
WaitForSingleObject
ExitProcess
SetFilePointer
GetFileAttributeSEx
CreateFile
CloseHandle
CreateDirectory
RemoveDirectory



OS architecture
monolithic system
layerd system(ring system)
microkernels(focusing on reliability, like Symbian and MINIX3)
client-server model(Web)
virtual machines(VMware,JVM)
Exokernals