Hard-Network

COMPUTER ARCHITECTURE QUESTIONS AND ANSWERS

Can you be able to identify between Straight- through and Cross- over cable
wiring?
Straight-through is type of wiring that is one to to one connection Cross-
over is type of wiring which those wires are got switchedWe use
Straight-through cable when we connect between NIC Adapter and Hub. Using
Cross-over cable when connect between two NIC Adapters or sometime between
two hubs.

What is cache memory?
Cache memory is random access memory (RAM) that a computer microprocessor
can access more quickly than it can access regular RAM. As the
microprocessor processes data, it looks first in the cache memory and if it
finds the data there (from a previous reading of data), it does not have to
do the more time-consuming reading of data from larger memory.(cache memory
is used between the c.p.u and the ram to access dta fastly)

What is hard disk and what is its purpose?
Hard disk is the secondary storage device, which holds the data in bulk, and
it holds the data on the magnetic medium of the disk.Hard disks have a hard
platter that holds the magnetic medium, the magnetic medium can be easily
erased and rewritten, and a typical desktop machine will have a hard disk
with a capacity of between 10 and 40 gigabytes. Data is stored onto the disk
in the form of files.

Where's MBR located on the disk?
Master Boot Record is located in sector 0, track 0, head 0, cylinder 0 of
the primary active partition.

What's the speed and device maximum specs for Firewire?
IEEE 1394 (Firewire) supports the maximum of 63 connected devices with
speeds up to 400 Mbps.

What's the difference between L1 and L2 cache?
Level 1 cache is internal to the chip, L2 is external. L1 Cache is of Higher
speed than that of L2 Cache.

Name the processor lines of two major manufacturers?
High-end: Intel - Pentium (II, III, 4), AMD - Athlon. Low-end: Intel -
Celeron, AMD - Duron. 64-bit: Intel - Itanium 2, AMD - Opteron

Where does CPU Enhanced mode originate from?
Intel's 80386 was the first 32-bit processor, and since the company had to
backward-support the 8086. All the modern Intel-based processors run in the
Enhanced mode, capable of switching between Real mode (just like the real
8086) and Protected mode, which is the current mode of operation.

Where does the Real mode on the CPU come from?
The original 8086, which only had 1 MB of memory. This megabyte is split
into low memory for IRQ tables, application memory and high memory.

How do you clear CMOS password?
Since CMOS is a special chip with its own battery, the best way to clear out
a CMOS chip is to disconnect it from its power supply.

What are the basic expansion card types?
ISA and PCI, ISA can be used only on XT, AT and ATX boards. The industry now
considers ISA obsolete.

What is a compiler?
Compiler is used to translate the high-level language program into machine
code at a time. It doesn.t require special instruction to store in a memory,
it stores automatically. The Execution time is less compared to Interpreter.

What is NV-RAM?
Nonvolatile Read Write Memory, also called Flash memory. It is also know as
shadow RAM.

What is called Scratch pad of computer?
Cache Memory is scratch pad of computer.

What is the difference between primary & secondary storage device?
In primary storage device the storage capacity is limited. It has a volatile
memory. In secondary storage device the storage capacity is larger. It is a
nonvolatile memory. Primary devices are: RAM / ROM. Secondary devices are:
Floppy disc / Hard disk.

What is meant by LATCH?
Latch is a D- type flip-flop used as a temporary storage device controlled
by a timing signal, which can store 0 or 1. The primary function of a Latch
is data storage. It is used in output devices such as LED, to hold the data
for display.

What is 1st / 2nd / 3rd / 4th generation processor?
The processor made of PMOS / NMOS / HMOS / HCMOS technology is called 1st /
2nd / 3rd / 4th generation processor, and it is made up of 4 / 8 / 16 / 32
bits.

Is the address bus unidirectional?
The address bus is unidirectional because the address information is always
given by the Micro Processor to address a memory location of an input /
output devices.

Difference between static and dynamic RAM?
Static RAM: No refreshing, 6 to 8 MOS transistors are required to form one
memory cell, Information stored as voltage level in a flip flop.
Dynamic RAM: Refreshed periodically, 3 to 4 transistors are required to form
one memory cell, Information is stored as a charge in the gate to substrate
capacitance.

Design Goals Of a Computer Architecture
The most common goals in computer architecture revolve around the tradeoffs
between cost and performance (i.e. speed), although other considerations,
such as size, weight, reliability, feature set, expandability and power
consumption, may be factors as well

What are Pipelining Issues?
Pipelining increases the CPU instruction throughput - the number of
instructions completed per unit of time. But it does not reduce the
execution time of an individual instruction. In fact, it usually slightly
increases the execution time of each instruction due to overhead in the
pipeline control.
The increase in instruction throughput means that a program runs faster and
has lower total execution time.

Limitations on practical depth of a pipeline arise from:
Pipeline latency. The fact that the execution time of each instruction does
not decrease puts limitations on pipeline depth;
Imbalance among pipeline stages. Imbalance among the pipe stages reduces
performance since the clock can run no faster than the time needed for the
slowest pipeline stage;
Pipeline overhead. Pipeline overhead arises from the combination of pipeline
register delay (setup time plus propagation delay) and clock skew.
Once the clock cycle is as small as the sum of the clock skew and latch
overhead, no further pipelining is useful, since there is no time left in
the cycle for useful work.

How do you detect if two 8-bit signals are same?
XOR each bits of A with B (for eg A[0] xor B[0] ) and so on. the o/p of 8
xor gates are then given as i/p to an 8-i/p nor gate. if o/p is 1 then A=B.

Difference between RISC and CISC?
RISC-Means Reduced Instruction Set Computer.a Risc system has reduced number
of instructions and more importantly it is load store architecture were
pipelining can be implemented easily.Eg.ATMEL AVR
CISC-Means Complex instruction set architecure.A CISC system has complex
instructions such as direct addition between data in two memory
locations.Eg.8085

What is pipelining?
A technique used in advanced microprocessors where the microprocessor begins
executing a second instuction before the first has been completed. That is,
several instructions are in the pipeline simultaneously, each at a different
processing stage.

What is Virtual Memory?
Virtual memory is a concept that, when implemented by a computer and its
operating system, allows programmers to use a very large range of memory or
storage addresses for stored data. The computing system maps the
programmer's virtual addresses to real hardware storage addresses. Usually,
the programmer is freed from having to be concerned about the availability
of data storage.
In addition to managing the mapping of virtual storage addresses to real
storage addresses, a computer implementing virtual memory or storage also
manages storage swapping between active storage (RAM) and hard disk or other
high volume storage devices. Data is read in units called "pages" of sizes
ranging from a thousand bytes (actually 1,024 decimal bytes) up to several
megabyes in size. This reduces the amount of physical storage access that is
required and speeds up overall system performance.