IBMBIO.COM is a system file in many DOS operating systems. It contains the system initialization code and all built-in device drivers. It also loads the DOS kernel and optional pre-loadable system components, displays boot menus, processes configuration files and launches the shell.

This file is part of the PC DOS all versions, and DR DOS 5.0 and above, with the exception of DR-DOS 7.06. It serves the same purpose as the file IO.SYS in MS-DOS or DRBIOS.SYS in DR DOS 3.31 to 3.41. For compatibility with some DOS applications, the file name ibmbio.com brief also uses the IBM version of OS / 2 1.0, where he was reminded of the file os2bio.com as used in Microsoft.

This file is in the root directory of a bootable fat-formatted disk / partition usually C:\ and usually has the system, hidden, and DOS 2.0 and read-only file attribute set. Under DR-DOS file can be optionally password protected as well. PC under DOS, the attribute system is installed in order to mark the file as property, the restriction is not technically necessary under DR-DOS. As IBMBIO.COM a binary image containing executable code and not a true program com-style set the hidden attribute to keep the file from random is called in the command line, which will lead to a crash. It is not necessary for DR-DOS version 7.02 and higher, because under these systems the file is a fat binary containing tiny com-style stab just to show some version information, and gracefully retired, when not loaded the boot sector.

In the boot sequence of the PC, the first sector of the boot Volume contains a boot loader called the volume boot record and VBR is loaded into memory and executed.

If this FBG PC DOS prior to 3.3 it will load both files in memory by itself. As the PC DOS and the FBG does not mount the FAT file system, the system files must be saved in the first directory on the recording disk and to be in a certain physical location on a disk, stored in consecutive sectors, conditions which the utility function sys should care.

If the loaded boot sector of PC DOS 3.3 or higher VBR, the requirements are slightly relaxed. The system files should still be saved in the first two entries of the root directory on the disk, but VBR will only use the first entry to download the first three sectors IBMBIO.COM in memory and transfer control to it. This part IBMBIO.COM contains several great Downloader that:

  • Calls the DOS kernels initialization routine.
  • Loads the rest of itself into memory. Before PC DOS 5.0 the system files still had to be stored at fixed physical positions on the disk and stored in consecutive sectors. With PC DOS 5.0 and higher this requirement was reduced down to the first three sectors of IBMBIO.COM only.
  • Initializes each default device driver in turn. At this point, the default devices are available.
  • Loads the DOS kernel. The kernel is stored in IBMDOS.COM.

Dr. DOS 5.0 and above, the first step is skipped, since DR-DOS FBG is capable of mounting a FAT file system, locate IBMBIO.COM or DRBIOS.SYS file somewhere in the root directory and load it into memory by itself. Name IBMBIO.COM file to load the boot sector stored in the boot sector, and not necessarily in the first root directory and the name IBMDOS.COM file to download IBMBIO.COM stored in IBMBIO.COM itself, and not necessarily in the second directory on the disk. Also, similar to IBMBIO.COM the loader in the FBG, in IBMDOS.COM a loader in IBMBIO.COM rudimentarily capable of mounting the filesystem as well, so it is not necessary for the system files stored in the first two directory entries to be in permanent positions or to be stored in consecutive sectors. Therefore, it is also no longer necessary to set the system attribute. Instead, the files can be simply copied to the disk without the system, Dan Dr-DOS already the boot sector is on disk.

Microsoft sometimes refers to this component of the system I / o, but is usually known as DOS and the BIOS in the DOS part of the base system of input-output. The term BIOS was originally coined by Gary Kildalls in 1975 for CP / M, but is also used to describe a similar component or layer in other operating systems, digital research, IBM, Microsoft and many others.

In a more General sense, some manufacturers refer to this part as the BIOS RAM operating system such as DOS or CP / m, to separate it with the built-in ROM BIOS of the machine.

  • IBMDOS. COM is the filename of the DOS kernel. Loaded and initially invoked by the DOS BIOS in IBMBIO COM during the boot process, it contains the hardware - independent
  • as they are contiguous COMMAND. COM can be treated like any ordinary file. MSDOS.SYS IBMBIO COM DRBIOS.SYS COMMAND. COM List of DOS system files The MS - DOS 5
  • System Files: IO.SYS or IBMBIO COM This contains the system initialization code and builtin device drivers. MSDOS.SYS or IBMDOS. COM This contains the
  • the equivalent of the CP M component in some DOS operating systems, IBMBIO COM in PC DOS IO.SYS, in MS - DOS NetBIOS Bermuda Institute of Ocean Sciences
  • DR DOS 5.0 and above, the DOS system files are named IBMBIO COM instead of IO.SYS and IBMDOS. COM instead of MSDOS.SYS. Older versions of DR DOS used DRBIOS
  • directives evaluated by the operating system s DOS BIOS typically residing in IBMBIO COM or IO.SYS during boot. CONFIG.SYS was introduced with DOS 2.0. The directives
  • IBMBIO COM and IBMDOS. COM are special binary images, not COM - style programs. Trying to load COUNTRY.SYS with a DEVICE statement or executing IBMBIO COM
  • system files, that is, the DOS - BIOS IO.SYS or IBMBIO COM and the DOS kernel MSDOS.SYS or IBMDOS. COM into the root directory of the target. Due to
  • leader of a system the equivalent of a city is called the COMMAND. COM IBMBIO COM IO.SYS starts the command processor as the first process SHELL
  • sector in form of a volume boot record VBR IO.SYS or IBMBIO COM MSDOS.SYS or IBMDOS. COM COMMAND. COM All files must be for the same version of the operating