Transcript Chapter 12

Supporting Windows
9x
Chapter 12
Key Terms
By Bill Ward
Bus enumerator

A component of Windows 9x Plug and
Play that locates all devices on a
particular bus and inventories the
resource requirements for these
devices.
Comment lines
Comment lines are documentation lines
that are ignored by a program.
 A REM in front of a line will comment
out an AUTOEXEC command.
 A semicolon will turn an .ini file line into
a comment.

Configuration manager

A component of Windows 9x Plug and
Play that controls the configuration
process of all devices and
communicates these configurations to
the devices
Disk thrashing
A condition that results when the hard
drive is excessively used for virtual
memory because RAM is full.
 This condition dramatically slows down
processing and can cause premature
hard drive failure.
 Some preventative measures for this
catastrophe would be:

– Back up data on a regular basis.
– Increase RAM.
Dr Watson
A Windows utility that tracks detailed
information into a log file about a failed
event and the software that caused it.
 Use this information to check the
Microsoft web site,
support.microsoft.com, for the problem
and solution.

Kernel
Core portion of an operating system
that loads applications and manages
files, memory, and other resources
 Uses mostly 32-bit code. The 16-bit
code is only retained as entry points
into the kernel from 16-bit application
programs.

Memory leak

A problem caused when an application
does not release the memory addresses
assigned to it when it unloads, causing
the memory heaps to have less and less
memory for new applications.
Plug and Play BIOS
(PnP)


Plug and Play is a set of design specifications
for both hardware and software that work
toward effortless hardware installations.
For a system to Plug and Play, it must meet
certain criteria:
– System BIOS must be PnP
– All hardware devices and expansion cards
must be PnP compliant.
– The OS must support Pnp.
– A 32-bit device driver(VxD) must be
Registry


A database used by the Windows operating system to store
configuration information. The Registry consists of the following major
sections:
– HKEY_Classes_Root - file associations and OLE information
– HKEY_Current_User - all preferences set for current user
– HKEY_User - all the current user information for each user of the
system
– HKEY_Local_Machine - settings for hardware, operating system, and
installed applications
– HKEY_Current_Configuration - settings for the display and printers
– HKEY_Dyn_Data - performance data
Most Windows applications write data to the Registry, at least during
installation. You can edit the Registry directly by using the Registry
Editor (regedit.exe). However, you must take great care because errors
in the Registry could disable your computer. Mr Goldman says,”Your all
big Girls and Boys who need to know how to do this.”
Safe mode

A specific way for the Windows operating system to load when there is a
system-critical problem interfering with the normal operation of Windows.
Safe mode allows the user to troubleshoot the operating system to
determine what is not functioning properly.

From the Startup menu, you can choose to enter safe mode yourself if
you know of a problem you want to correct.

To shutdown and restart your computer in safe mode:
– Click Start, and then click Shut down.
– Click Restart, click OK, and then press and hold the CTRL, key until
the Microsoft windows 98 startup menu appears

For some machines, you can use F8 instead of CTRL to bring up
the Microsoft Windows 98 Startup Menu.
– Enter the number for Safe Mode.
Virtual machines
(VM)

A self-contained operating environment that behaves as if it is a
separate computer. For example, Java applets run in a Java
virtual machine (VM) that has no access to the host operating
system This design has two advantages:



System Independence: A Java application will run the
same in any Java VM, regardless of the hardware and
software underlying the system.
Security: Because the VM has no contact with the
operating system, there is little possibility of a Java
program damaging other files or applications.
The second advantage could be considered a disadvantage.
Because programs running in a VM are separate from the
operating system, they cannot take advantage of special
operating system features.