Disk Operating System

,o[,op,op Okpoklkoko;l;,l;,lDisk Operating System DOS Load Sequence 1. ROM BIOS & POST 2. IO.SYS Contain I/O device driver & control the rest of the boot process 3. MSDOS.SYS Contains DOS kernel code, convert request from application into actions that IO.SYS can perform with hardware device drivers. 4. CONFIG.SYS Load extra hardware device driver not built in to IO.SYS 5. COMMAND .COM Provides DOS prompt, load internal DOS command, DOS directory in DOS 6.x using the SHELL & COMSPEC command . 6. AUTOEXEC.BAT Loads (Terminate Stay Resident Programs) TSRs such as VSAFE (MS AntiVirus) & DOSKY, set up environment variables such as TEMP & PATH & any programs such as NT workstation software & windows DOS Versions 1. Version 1.0 – Aug 1981 2. Version 3.3 –Apr1987 3. Version 6.22 -- Oct 1993 4. Version – windows95 DOS Command 1. Internal DOS Command Built into COMMAND.COM ( for more useful internal command please refer to your book (pg 13-2) 2. External DOS Command IT store on your hard disk on DOS directory(usually C:\DOS),the files name normally end COM (command files) & EXE(executables) ( for more useful external command please refer to your book (pg 13-3). 3. Batch Files Notepad file create by dos command normally end with BAT extension For more information please refer to you book chapter 13