System Software Q & A

8/19/2019 System Software Q & A

http://slidepdf.com/reader/full/system-software-q-a 1/7

103MCA24 FAQ and Answers

1

1. What is system software? How it is different from application software? Explain with

examples.

Ans: System software consists of a variety of programs that support the operation of a computer.

This software makes it possible for the user to focus on an application or other problem to be

solved, without needing to know the details of how the machine works internally.

System Software

1. System software acts an

interface between an

application and the computer

hardware.

2. System programs are intended

to support the operation and

use of computer itself .

3. System software deals with

the architecture, i.e., system

software is machine

dependent.

4. System software is an

essential part of computer

operations. The functions of

system software includes

managing the computer

resources and facilitate

program development.

. !"amples# $perating

systems, assemblers,

compilers, system libraries,

utility programs.

Application Software

1. %pplication software acts as an

interface between user and the

system software&$S'

2. %n application program is

primarily concerned with the

solution of some problem, using

computer as a tool.3. %pplication software does not

deal with the architecture of a

computer ,i.e., application

software is machine independent.

4. %pplication software are

designed to perform specific

tasks, these are designed to meet

end(user re)uirements.

. !"amples# Spreadsheets,

wordprocessors, media players,

database applications.

s.Saraswati R. Bhusanur System

Programming



+onditional ;ump instructions# &:T, :!=, :>T', these instructions test the setting of ++

and ;ump accordingly.

There are no memory(memory move instructions.

Input and &utput

<erformed by transferring 1 byte at a time to or from the rightmost bits of register %

&accumulator'.The Test evice &T' instruction tests whether the addressed device is ready to send or

receive a byte of data.

-ead ata &-', ?rite ata &?' are used for reading or writing the data.

'. Write the instruction format of SI. Explain the different addressin# modes used.

In SI Std (ersion:

*nstruction formats

%ddressing modes#

There are two addressing modes available.

&6' is content of " register

In SI )*E +ersion:

4 formats are available.



?here, n is indirect addressing

i is indirect

" is inde"ed

b is base relative

p is program counter relative e for format 3 or 4

Addressin# modes:

$irect &", b, and p all set to @'

!"# % !5>TA

"elati(e &either b or p e)ual to 1 and the other one to @'

!"# ST% %<A%

Immediate &i B 1, n B @'!"# % C@

Indirect &i B @, n B 1'

!"# ST% D87//!-

Indexed &" B 1'!"# % %<A%,"

%ormat ' or ,

e B @ means format 3 !"# % !5>TA

e B 1 means format 4 !"# E % !5>TA

,. What are the ma-or difference etween SI and I)*E machines.

S*+ Std version S*+ 6! version1. !emory:

21 bytes in the computer memory, that is 32,0

bytes

2. "e#isters:

%i(e re#isters, each 24 bits in length. %, , 6,

<+, S?

'. $ata %ormats

*nteger &3 byte' and +haracters&%S+** code'are

supported.

,. Instruction %ormat:

%ll are 24 bit wide.

1. !emory:

Total &S*+F6!' B 22@ &1,@4,0' bytes

&18'

2. "e#isters:

/otal 0 resisters. %long with %, , 6, <+,

6! version has 8, S, T, /

'. $ata %ormats

%long with *ntegers and +haracters, %loatin

point (ariales are supported.

,. Instruction %ormat:/our *nstruction formats are present

/ormat 1# 1 byte

/ormat 2# 2 byte



. Addressin# modes

Two addressing modes irect and inde"ed.

. Instruction sets

/here are no memory3memory mo(e

/ormat 3# 3 byte

/ormat 4# 4 byte

. Addressin# !odes

$irect &", b, and p all set to @'

!"# % !5>TA

"elati(e &either b or p e)ual to 1 and

other one to @'

!"# ST% %<A%

Immediate &i B 1, n B @'

!"# % C@

Indirect &i B @, n B 1'

!"# ST% D87//!-

Indexed &" B 1'

!"# % %<A%,"

%ormat ' or ,

e B @ means format 3

!"# % !5>TA

e B 1 means format 4

!"# E % !5>TA

. Instruction set

%long with normal arithmetic, compa

;ump, load and store instructions4 it has

memory3memory mo(e instructions.

!"# -$, -S78, +$<-, SA*/T-, SA*/T



instructions.

5. Input and &utput

' instructions are used.T Test the device

- -ead from the device

? ?rite into the device

%-, S78-, 7-, *9-,

Arithmetic operation on %loatin# data

%/, S78/, 7/, *9/

5. Input and &utput

Instruction are available 6/$4 "$4 Wd

SI&4 HI&4 /I&7

There are I)& channels that can be used t

perform input and output while the +<7 i

e"ecuting other instructions.

' additional instructions are pro(ided:

G SI& Start *F$

G HI& Aalt *F$

G /I& Test *F$

.Explain the data formats and Instruction formats of SI)*E machine.

Ans: $ata formats:• *ntegers are stored in 24 bit, 2Hs complement format

• +haracters are stored in (bit %S+** format

• /loating point is stored in 4 bit signed(e"ponent(fraction format#

G The fraction is 3 bit number and has value between @ and 1.

G The e"ponent is 11 bit unsigned binary number between @ and 2@40. G The sign of the floating point number is indicated by s # @Bpositive,

1Bnegative.

G The absolute floating point number value is# fI2&e(1@24'

Instruction formats

4 formats are available.



?here, n is indirect addressing

i is indirect

x is inde"ed

is base relative

p is program counter relative

e for format 3 or 4

System Software Q & A

Documents

Transcript of System Software Q & A