Getting to Know the Operating Systems

Getting to Know the Operating Systems

It may not be easy for you to track down a version of each of the operating systems you need to know for the exam (see "Getting down to specifics" earlier in the chapter). So, the following sections give you a brief overview of the features of each OS.

For the OS Technologies exam, you must have an understanding of the foundation components of the various versions of the Windows operating systems, including their interfaces, 16-bit and 32-bit support, and all the virtual stuff that's really there.

Getting to know Windows 95

In addition to an updated and improved user interface, Windows 95 brought 32-bit capabilities to PCs with Intel processors. The differences to the earlier Windows 3 .x are the following:

l Backward compatibility:

Windows 95 supported legacy devices requiring system file (AUTOEXEC.BAT and CONFIG.SYS) support to load device drivers. It also supported most 16- bit DOS and Windows 3 .x applications. Windows 95 supported Plug and Play devices and referred to all non-Plug and Play cards as legacy cards.

l Setup and configuration: Windows 95 could be installed from a network server or from a CDROM and included auto-detection of hardware and Plug and Play support during setup.

l Improved user interface: Windows 95 added the Start button, taskbar, and properties sheet (along with a use for the right mouse button) and eliminated the program groups from the desktop.

l Protected mode: Windows 95 allowed applications to run in protected mode where DOS and Windows 3 .x restricted applications to real mode.

l 32-bit application support: Windows 95 runs 32-bit applications with private memory space, preemptive multitasking, and multithreaded execution. Windows 95 also supports the 16-bit code of the DOS/Windows 3 .x environment.

l Instant Answer Peer-to-peer networking: Although first introduced in Windows for

Workgroups, Windows 95 (and later Windows 98) improved its capabilities, operation, and setup.

Windows 95 also added peer services for Novell networks.

l Virtual machine: Windows 95 implemented the concept of the virtual machine, which allowed it to run applications from other operating systems (primarily DOS and Windows 3.x) in a nearly native environment.

Getting to know Windows 98

Time Shaver Perhaps the best way to review an operating system for the OS Technologies exam is practice navigating around the various Properties functions of Windows 98, including those accessed by right-clicking the desktop and the My Computer icon. You should also review the functions on the Settings menu and the System, Printers, Modems, and Network icons of the Control Panel. The exam has questions about how to access each of these functions and the kinds of actions available on each.

Windows 98 (and Windows 95) supports both 16-bit and 32-bit applications through the Windows Application Programming Interface (API). The API provides application developers with a library of utilities that perform a variety of tasks in the Windows environment. The primary components of the API are the following:

l Kernel (KERNEL32.DLL) contains the essential operating system functions, including memory, file, and I/O management, and application support.

l User (USER32.DLL) controls the user interface including the mouse, keyboard, I/O ports, and the desktop layout.

l GDI (GDI32.DLL) manages graphics and controls printing.

When an application creates a window, the window resource is stored in the USER.DLL resource table; when an application loads a picture or graphic, it is stored in the GDI.DLL resource table; and when an application opens a disk file, the file's information is stored in the KERNEL.DLL resource table. If an application does all three, the resources required to support the application in memory is tripled. This arrangement creates USER, GDI, and system KERNEL resources instead of general system resources.

Remember The Windows Resource Meter, a utility that is available on Windows 9x, monitors the utilization of Windows' resources by all the applications, applets, and utilities running on the system.

Meeting Windows 98 Second Edition (SE)

In the confusion surrounding just what Windows 2000 was replacing or enhancing, Windows 98 Second Edition (SE) was released. Operationally, it is not different from Windows 98, but it did fix many bugs of the first edition, improved some device support, and added a few new features, including Internet Connection Sharing.

Remember Internet Connection Sharing (ICS) allows home, home-office, and small office users to share a single Internet connection, such as a dialup proxy server, a DSL (Digital Subscriber Line) connection, a UNII (unlicensed national information infrastructure) wireless line, or perhaps a frame relay connection over a peer-to-peer or local area network. ICS assumes a network to be present and isn't fussy about the type of network or the media used.

Differentiating Windows 95 and Windows 98

Windows 95 and Windows 98 are actually pretty much the same. They share the same architecture and the function same in every major area. Windows 98 is often described as Windows 95 OSR2 with Internet Explorer, a few new device drivers, and some housekeeping utilities added.

Windows 98 did add some features and functions that do differentiate the two operating systems including the following:

l Active Desktop and Internet Explorer: Windows 98 allows the desktop and folders to be viewed as a Web page and includes Internet Explorer.

l Fixes, patches, and additions: Windows 98 incorporated all the user service packs and OEM updates (OSRs) that had been released for Windows 95. Most prominent among these were the following:

¡ System Configuration utility: Used to modify the startup files (AUTOEXEC.BAT, CONFIG.SYS), the Registry, and so on.

¡ FAT32 Converter: Converts an existing FAT16 disk format to the more efficient FAT32 format. However, this action cannot be reversed.

¡ Task Scheduler: Typically, used to set up regular runs for maintenance tasks, but can be used to run any program at a set time or date.

¡ Dr. Watson: This utility is used to aid troubleshooting of application program crashes.

¡ Registry checker: Automatically repairs, compresses, and backs up the Registry files.

l New device support: Windows 98 included support for several new devices, including:

¡ USB and IEEE 1394 (FireWire) devices

¡ OnNow and ACPI (Advanced Configuration and Power Interface), which allow      the PC to

be put to sleep instead of powered down.

¡ DVD (Digital Versatile Disc) drives and TV tuners

¡ Multiple monitors