1. Working in DOS DOS is a true operating system
An operating system does 4 things:
it must communicate with the hardware
it must create a user interface
must allow users to use and manage programs
must allow users to add, move and delete the installed programs

2. DOS
Until version 5.0 you could only get DOS on a PC and not off the shelf
Memorize chart on page 520
Files in DOS-
Filename no longer that 8 characters
Extension up to 3 characters
No spaces in filename or extension
Cannot use /\[]<>+=;,*?
REMEMBER WIN 95/98 DOES HAS 255 CHARACTER LIMIT

3. DOS DOS cannot support more than 2 floppy drives
Files organized into directories and subdirectories (folders in Windows)
Exact location of file called its path
Anything not in directories is in the root directory

4. 3 Main Files of DOS THESE FILES MUST BE ON COMPUTER OR IT WON’T BOOT!
IO.SYS- handles talking to BIOS and hardware
MSDOS.SYS-primary DOS code, the kernel
COMMAND.COM-interprets commands, called command interpreter, displays DOS prompt
These files not interchangeable on different versions of DOS

5. DOS commands
ATTRIB- changes attributes to either read, system, hidden or archive
DELTREE-deletes a directory and its subdirectory and all their files
CD- changes directory
MD- creates directory
DIR/W- to see files in wide format

6. MORE DOS
Wildcards- use a * to find all files with similar text, example- *.com to find all files that end in .com. The ? Symbol can be used to find matches for individual characters
Deleting- done with the DEL or ERASE commands
Copying- COPY
Moving- MOVE

7. Config.sys in DOS Following found in Config.sys used in DOS for
device drivers
buffers= statement (buffers are a temporary assembly area for files in memory)
stacks= statement allows CPU to set aside registers
files= statement how many file handles

8. Sample CONFIG.SYS file Device=C:\DOS\HIMEM.SYS
Device=C:\DOS\EMM386.EXE 1024 RAM
FILES=30
BUFFERS=15
STACKS=64,500
DEVICE=C:\DOS\SMARTDRV.SYS 1024
DOS=HIGH, UMB
DEVICEHIGH=C:\MOUSE\MOUSE.SYS
DEVICEHIGH=C:\DOS\RAMDRIVE.SYS 4096/a

9. AUTOEXEC.BAT
Another way to support devices is through TSR’s (terminate and stay resident) programs. These are located in Autoexec.bat. One of the most common TSR’s is for mice
DOSKEY.COM- is a TSR that keeps track of commands
MODE command changes look of monitor
SHARE command prevents file from being used by more than one program

10. DOS commands
SET command creates environmental variables so DOS programs can read them
PATH- command tells user where to look for file when not found
PROMPT- determines what prompt looks like

11. Using Commands for Drives in DOS
FDISK- partitioning
FORMAT- high level format
VOL- see the volume label of drive
SYS- copies 3 system files to partition making it bootable. Can make bootable floppies with it
LASTDRIVE- allows for memory allocation beyond the 2 extra drive letters beyond C

12. Checking Drives
CHKDSK- identifies and repairs lost cluster chains. Will identify but not repair cross linked files (2 files trying to claim same cluster)
SCANDISK- repairs lost clusters, cross linked files, directory and file structures, file allocation tables, even volume labels
DEFRAG-

13. Smartdrv Initiated from the autoexec.bat file Is a software disk cache
When run with /s will tell you efficiencly of disk cache
Page 558 and 559 gives possible command combinations