 The magazine of the Melbourne PC User Group Beginners Basics: Part 8 Ron Wilby |
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Hi there everybody. Ready for another trip through the heavyweight stuff? Last time I set out to talk about the startup files. I only got to the disaster disk stage, but I'm getting a lot of phone calls from readers who've got a disaster but no disaster disk. If you didn't make a disk after being frightened by my last piece, make one now.
CONFIG.SYS commands
Last month I mentioned that there are fifteen commands (sometimes called directives) which DOS allows us to put in our CONFIG.SYS file. Let's talk briefly about them.
The COUNTRY command
This sets the format of the date and time display. This means that you and your DOS put dates in the form dd-mm-yy so you don't get confused by the American date format we often find in our software. To do this, you must put a line in your CONFIG.SYS file, like this
COUNTRY=061,,C:\DOS\COUNTRY.SYS
Yes, two commas between the country code number (061 for us) and the path required to find the file COUNTRY.SYS. This line will also change you over to Australian currency and eliminate any strange characters from your text.
The DEVICE command
DOS can work with many peripherals (read things you hang on your computer, like printer or mouse). Your keyboard and monitor (screen) are treated as devices by DOS. To talk to these, DOS requires a separate device driver to be provided for each one, otherwise DOS would have to be reworked for each new printer or keyboard which appeared on the market.
Some of these drivers, such as floppy and hard disk controllers come as part of DOS. Also included are monitor, keyboard and input/output controllers. Other drivers need to be loaded by a line in the startup file CONFIG.SYS. Note that unless the driver is in your hard disk root directory, you'll need to tell DOS how to find it. You may need a PATH like C:\DOS\filename. This tells DOS to go from root directory (\) to DOS directory (DOS\) and then look for your driver's filename.
A Device Driver is a low-level (means your computer can read it but you can't) program that goes between DOS and a device. DOS uses this program to control it. Whatever device drivers you want to be available while running your computer must be loaded at startup time from CONFIG.SYS. The syntax (fancy name for the words you've got to type) for these device commands is
DEVICE=d:path\filename
That's the line which goes into CONFIG.SYS, where d: is the drive name (A:, C: or whatever) and path is the route DOS must follow from one directory to another in finding the required device driver (filename). If the driver ANSI.SYS is in your directory called DOS, then to load it you'll need this line in your CONFIG.SYS file
DEVICE=C:\DOS\ANSI.SYS
For another device driver you'll need another similar line with the appropriate device name instead of ANSI.SYS.
Other CONFIG.SYS commands
- DEVICEHIGH: (DOS 5 or higher) allows some device drivers to be loaded into high memory, above the 640 KB limit of conventional memory. DOS (DOS 5 or higher) allows most of DOS to be loaded into high memory.
- DRIVPARM: Modifies the parameters of an existing disk drive.
- FCBS Obsolete command used by early versions of DOS.
- FILES: Sets the number of files which can be open at any one time. Some of your programs will modify your CONFIG.SYS file at installation time, others will tell you should have a FILES command. This is just a line which says FILES=nn, where nn is a number, usually in the range 20 to 40, although Windows is supposed to run faster with FILES=60.
- INSTALL: is used to install memory resident programs.
- LASTDRIVE: sets the number of valid drive letters.
- REM. Put this at the beginning of a line of your CONFIG.SYS file and that line is flagged as a "remarks" line, not a command. A line with REM at the beginning is not executed (carried out). Other commands are SHELL, STACKS and SWITCHES. We don't need to bother with these now and FCBS is obsolete. Let's see how you can use some of the others.
It's important to make good use of whatever memory you have. To do this, you need some memory managers. HIMEM.SYS and EMM386.EXE are two which are included with DOS 5 and 6.xx. There are also many third-party (not you - not Microsoft but a third party) memory managers available, better than DOS according to those who paid good money for them.
Here CONFIG.SYS gets a little tricky. The actual order of the commands becomes important. Since most of us these days have at least some Extended Memory (that's memory beyond the old 640 KB limit), the first line in your CONFIG.SYS file should be
DEVICE=C:\DOS\HIMEM.SYS
and the second line should be
DEVICE=C:\DOS\EMM386.EXE RAM
These two lines make sure that both memory managers are loaded and assumes that they're to be found in the directory called DOS. If they are in the root directory, put DEVICE=HIMEM.SYS, since DOS will look in the root directory first. Next you should have these lines
DOS=UMB
DOS=HIGH
UMB means Upper Memory Blocks. These are parts of the upper memory area (between 640 KB amd 1 MB) that may be available. This area is supposed to be kept for your system hardware, such as your monitor, and for that reason is not considered part of your memory. Usually there are unused blocks available in which parts of DOS can be stored.
The DOS=HIGH line means that DOS can be loaded into Extended Memory. That's memory above the conventional memory (640 KB) and above the upper memory area. That's the memory you pay for when you buy 8 MB of RAM.
Configuration files
These can come next, they are FILES= and BUFFERS=, see above for the numbers to add to these lines.
After that it's a question of what device drivers, disk drives etc. you have and you want to load. Your CONFIG.SYS file will be different from everybody else's. Somebody has probably already decided what you need and so you have a working computer with a satisfactory CONFIG.SYS. We won't change it.
Practical work section
This is hard this month, because you are all different. Still, we'll have a go. If you have a good backup system and know how to use it to restore a particular file, you can skip this part. I suspect that injunction leaves around 90 percent of our readers still with me. First, get two floppy disks. Put one in the drive, shut the door and get to the DOS prompt (if you've forgotten how to do that, go back to earlier parts of this series). Now copy your CONFIG.SYS to the floppy. Type COPY CONFIG.SYS A: and then DIR A: to check that it's there. Put these two floppies away safely, then you can use them to restore any damage we might do messing with your CONFIG.SYS file.
A new CONFIG.SYS
To alter CONFIG.SYS, don't retype anything, use the REM instruction at the beginning of a line to effectively delete that line, while leaving it there so you can see what you "deleted."
Type EDIT CONFIG.SYS to get the file on screen and add the REM instruction.
Now, use the MEM command (assuming you're working with DOS 5 or 6.xx - look at your DOS manual to select the correct switches, they are different in versions 5 or 6). MEM/C for DOS 6 shows you the state of your memory so print this using your Print Screen key.
Next, REM out the lines DOS=HIGH and DOS=UMB and reboot your computer, using the reset button or Ctrl+Alt+Del pressed together. Use MEM once again and note the effect of your changes, printing again so you can compare.
Now you can try REM on the lines with HIMEM.SYS and EMM386.EXE, thus forcing DOS to use the 640 KB of "conventional" memory. Reboot and have another look with MEM to see the effect of your changes. When you've finished, go back to the editor and delete all the REMs and everything should be just as it was except that you have more knowledge of CONFIG.SYS and how it works.
Play around with the other commands in CONFIG.SYS and see what happens. If you mess things up, you can always restore from your backup or from the floppies you made before you started. Enough for this month.
Reprinted from the July 1995 issue of PC Update, the magazine of Melbourne PC User Group, Australia
