Yes, we can Install the Operating System in USB Portable 
Drive.

first chekout the inside buscables,powrcables. after that
repair the operating system.

Technology Systems

technology systems

As i know these 3 are the Definition of "TSY" Acronym.
TSY Technology Systems (Bellcore) 
TSY Telephony Subsystem 
TSY The Sophomore Year (band)

java provides thread mechanism

java

Java is not the operating system.
Unix provide multithreading but ms-dos doesnt.

java

DNS

Static IP, Network cable should be terminated, Server Name
and Domain Name

e

a

c      bcoz virtual memoy means the external memory that we 
connect to our system ie harddisk

a

[d] a & c

Size of Virtual Memory depends on the size of the System 
RAM installed, generally the size spans a minmimum 1.5-2 
times to maximum 3-4 times of the RAM. However, this space 
is taken from free space available on the Hard Disk Drive 
of Computer.
If I understand correctly, the "size" of Virtual Memory 
depends on the RAM installed. Hence, the answer should 
be "[e]".

Semaphores r software, blocking, OS assistance solution to 
the mutual exclusion problem .It is
basically a non-negative integer variable that saves the 
number of wakeup signals sent so they are not lost if the 
process is not sleeping 

another interpretation is that the semaphore value 
represents the number of resources available 

Semaphore is a machanism to resolve resources conflicts by
tallying resource seekers what is the state of sought
resources, achieving a mutual exclusive access to resources.
Often semaphore operates as a type of mutual exclusive
counters (such as mutexes) where it holds a number of access
keys to the resources. Process that seeks the resources must
obtain one of those access keys, one of semaphores, before
it proceeds further to utilize the resource. If there is no
more such a key available to the process, it has to wait for
the current resource user to release the key.

A semaphore, a new variable type.
A semaphore could have the value 0,indicating that no 
wakeups were saved, or some positive values if one or more 
wakeups were pending.
a semaphore s is an integer variable that apart from 
initialization, is accesssed only through two standard 
atomic operations, wait and signal. these operations were 
orignially termed p(for wait to test) and v(for signal to 
increment).
The classical defination of wait in psedocode is
wait(s)
{
while(s<=0)
;// no-op
s--;
}
The classical defination of signal in psedocode is
signal(s)
{
s++;
}
Modification to the integer value of smaphore in wait and 
signal operations must be executed individually.
that is, when one process modifies the semaphore value no 
other process can simultaneously modifiy that same 
semaphore value.

semopore is s\w

A set of processes is deadlocked if each process in the set 
is waiting for an event that only another process in the 
set can cause (including itself). 
To avoid these r the stratagies to be followed

 
Attacking Mutex condition 
Attacking preemption 
Attacking hold and wait condition 
Attacking circular wait

Deadlock is permanent blocking of the set processes that 
either compete for system resources or communicate each 
other.
we can avoid deadlock by avoiding the following conditions:
1.Mutual Exclusion
2.Hold and wait.
3.No preemption.
4.circular wait.

It depends on what type of scheduling policy has been
chosen. In general, the way to schedule the time quantum
(time slice)is either to take a fixed or variable length of
time unit. In an adaptive style of scheduling policy, the
scheduler will give a high priority process as much time as
it needs unless another higher priority process comes in the
ready queue to demand quantum of execution time. In this
case, a variable number of time units will be given to that
process. However, in a round-robin style of scheduling
policy, the time quantum is fiexed and predefined, and each
of processes that gets its turn to run through the time
quantum will complete the full length of the time unit
allocated to it before a context switch takes place. In
other words, the scheduler has to schedule the processes
according to its scheduling policy as it's been designed.

Direct memory access

DMA--> Direct Memory Access is the Right answer
  which is given in gelvin Operating System 6Th edition...

Direct Memory Access

2 power30

why is it 2 power 30, and not 4 power 15?

answer is 'A'