How Hardware and Software Work Together
– Stands for automatically executed batch file, the file that DOS automatically executes when
a computer boots up. This is a convenient place to put commands you always want to execute at the beginning
of a computing session. For example, you can set system parameters such as the date and time, and install
– (Another name for subdirectory)
A directory or folder contained in another directory or
– A group of disk sectors. The operating system assigns a unique number to each cluster and then
keeps track of files according to which clusters they use.
the CMOS configuration chip.
The program in system BIOS that can change
the values in the CMOS RAM.
– The configuration file for DOS systems. Whenever a DOS computer boots up, it reads the
CONFIG.SYS file (if it exists) and executes any commands in it. The most common commands are BUFFERS=
and FILES=, which enable you to specify the buffer size and the number of files that can be open
simultaneously. In addition, you can enter commands that install drivers for devices.
– In graphical user interfaces, a desktop is the metaphor used to portray file systems. Such a desktop
consists of pictures, called icons that show cabinets, files, folders, and various types of documents (that is,
letters, reports, pictures). You can arrange the icons on the electronic desktop just as you can arrange real
objects on a real desktop -- moving them around, putting one on top of another, reshuffling them, and throwing
– A program that controls a device. Every device, whether it be a printer, disk drive, or
keyboard, must have a driver program. Many drivers, such as the keyboard driver, come with the operating
system. For other devices, you may need to load a new driver when you connect the device to your computer. In
DOS systems, drivers are files with a.SYS extension. In Windows environments, drivers often have a.DRV
A driver acts like a translator between the device and programs that use the device. Each device has
its own set of specialized commands that only its driver knows. In contrast, most programs access devices by
using generic commands. The driver, therefore, accepts generic commands from a program and then translates
them into specialized commands for the device.
Direct Memory Access (DMA) Channel
– a technique for transferring data from main memory to a device
without passing it through the CPU. Computers that have DMA channels can transfer data to and from devices
much more quickly than computers without a DMA channel can. This is useful for making quick backups and
for real-time applications.
Some expansion boards, such as CD-ROM cards, are capable of accessing the
computer's DMA channel. When you install the board, you must specify which DMA channel is to be used,