Acronis os selector 8.0 User Manual
3. Boot manager initializes the memory, scans the partition structure and
assigns letters to partitions, defining the DOS boot partition on the way.
4. Then the boot manager reads the DOS configuration file (CONFIG.SYS)
and if it contains multiple configurations displays a menu on the screen
prompting you to choose one of them, otherwise it just reads the
configuration and loads the indicated drivers and operating system parts
from the second DOS file.
prompting you to choose one of them, otherwise it just reads the
configuration and loads the indicated drivers and operating system parts
from the second DOS file.
5. After the configuration file has been processed, command interpreter
(default COMMAND.COM) is loaded and executed. Command interpreter
is a plain DOS program.
is a plain DOS program.
There are several differences between DOS versions from different vendors:
• MS-DOS 5.x–6.x and PC-DOS assume that their files should be the first
ones in the root folder.
• MS-DOS 5.x–6.x system files have names IO.SYS and MSDOS.SYS.
• PC-DOS and DR-DOS 7.x system files have names IBMBIO.COM and
• PC-DOS and DR-DOS 7.x system files have names IBMBIO.COM and
IBMDOS.COM.
• MS-DOS 7.x/8.0 have one large system file IO.SYS and MSDOD.SYS
becomes a configuration file.
• MS-DOS and PC-DOS assume the boot partition as the partition to which
letter C: has been assigned.
• CONFIG.SYS command set differs for different DOS versions.
• MS-DOS 7.x/8.0 starts WIN.COM instead of COMMAND.COM if the
• MS-DOS 7.x/8.0 starts WIN.COM instead of COMMAND.COM if the
MSDOS.SYS file has BOOTGUI=1.
• MS-DOS 8.0 cannot function as a stand-alone operating system.
CONFIG.SYS and AUTOEXEC.BAT files processing are blocked. It can
only boot the Windows operating system. A special MS-DOS 8.0 version
on the Windows ME boot disk can function as a stand-alone operating
system, but a check is built into it so that it can only be booted from a
diskette.
only boot the Windows operating system. A special MS-DOS 8.0 version
on the Windows ME boot disk can function as a stand-alone operating
system, but a check is built into it so that it can only be booted from a
diskette.
9.1.3
System and Configuration Files
Here is the DOS system files list:
• IO.SYS (mandatory for MS-DOS);
• MSDOS.SYS (mandatory for MS-DOS 5.x–6.x);
• IBMBIO.COM (mandatory for PC-DOS);
• IBMDOS.COM (mandatory for PC-DOS);
• DBLSPACE.BIN (mandatory for MS-DOS 5.x–6.2);
• MSDOS.SYS (mandatory for MS-DOS 5.x–6.x);
• IBMBIO.COM (mandatory for PC-DOS);
• IBMDOS.COM (mandatory for PC-DOS);
• DBLSPACE.BIN (mandatory for MS-DOS 5.x–6.2);
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Chapter 9 : Particularities of Operating System Functioning