IO.SYS - MS-DOS and Windows 9x system file. It contains device drivers (routines for working with devices) for MS-DOS and a DOS initial setup code. [one]
At boot time, the contents of the first sector of the boot disk are loaded into memory and control is transferred to it. If this is the DOS boot sector , then it loads IO.SYS into memory (the details of this procedure differ in different versions of DOS) and transfers control to it. Then IO.SYS:
- Initializes drivers for the console , disk, serial port , etc.
- In MS-DOS, it loads the DOS kernel from MSDOS.SYS and initializes it. The Windows 9x IO.SYS bundle already contains the DOS kernel in itself, and the MSDOS.SYS file is a text file where you can specify system settings.
- Processes the CONFIG.SYS file.
- Loads COMMAND.COM (or another shell of the operating system that is specified in CONFIG.SYS).
- On Windows 9x, displays the boot screen. If the Logo.sys file is present , then it is used to display the splash screen. [2]
In MS-DOS clones, the boot file with the system kernel may be called differently. For example, in PC DOS and DR-DOS the file is called IBMBIO.COM , in FreeDOS it is called KERNEL.SYS.
Notes
- ↑ Extension module for the basic input-output system (IO.SYS) . Date of treatment June 29, 2012. Archived on August 7, 2012.
- ↑ Understanding the Windows 95 boot Sequence . Date of treatment June 29, 2012. Archived on August 7, 2012.
Links
- Driver names cannot be used as file names - includes a list of default device drivers
- SYS.COM Requirements MS-DOS Version 2.0-6.0 - Includes requirements for downloading IO.SYS