- Ads:
 Easy to write
 Easy to understand
 Known the processing data in CPU
 Prog writing is shortset
- Dis:
 Must be complier
 The time of running prog is longer than machine language
3. High level language
- HLL was developed in order to further easy the work of programmers by
making the programming language more procedure oriented
- Features:
 The statements of HLL are closer to natural english or other
natural language
 A HLL source program must be translated into machine
code by means of a compiler or an interpreter
- Ads:
 Easy to wirte
 Easy to understand
 May be used for everybody
 Closed to natural languages english language
- Dis:
 Must be interpreter by compiler or an interpreter before
processing by the computer
 The prog is long
 The time to run the prog is longer than low level language
Question 2. Some High Level Languages (HLL)?
1. COBOL: Common Business Oriented Language
- COBOL is an exetensively used HLL and since around 1960 several
versions have appeared
- The original intention was that COBOL should be capable of being

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- Essentially BASIC consists of statements made up of verbs & variables.
The verbs are similar to those in COBOL but there is a large to them that
in effect become the addresses of their locations in the main store
- A variable name must be unique and generally consists of one or a few
alphabetic characters, purhaps followed by a digit
3. PASCAL: named after the famous 17
th
century French mathematician
- It was expressly designed as a language to make programming more
systematic and discriplired and in these respects lends itself to structured
programming
- It is however more difficult to learn than are COBOLS BASIC and so is
unliked to be accepted as a language for microcomputers are geared to
BASIC only
Question 3. Operating Systeim?
- Concept of OS:
 An OS consists of a suite of programs, one of which, the
master, kernel or exeactive program, remains resident in the
main store. This program controls the other OS programs in
th suites and between them they controls the application
programs
 Often the operating system includes various application
packages among its suit of programs. Ex of such software
include: word processing, electronic mail, networking,
speadsheet, graphics and file handling
- Function of OS
 Pricrity assignment:
Jobs waiting execution are scheduled according to either a predetermined or a
dynamic assignments plan
 Control of multiprogramming

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 Application package control
Especially with microcomputers, as describe above

Chapter 6: TRANSLATORS.
Question 1. Translators?
1. Assemblers
 Def: A program that translates assembly language into machine code. Dos
machine instruction is generated for each source instruction
- The resulting program ran only be executed when the assembly process is
completed
 Operation:
- Translates mnemonic operation codes into machine code & symbolic
address into machine address
- Includes the neressary linkages for closed subroutines and inserts
appropriate machine code for macros
- Allocates area of storage
- Detects and indicates valid source language instruction
- Procedures the object program on tape or disk required
- The lesting may also include error codes if appropriate. To illustrate the
methods used just think about an assembly program. We must first look at
the directives
 A directive is used to control the assembly process, it is not
asembled but is obeyed by the assembler when it is
encouteded, e.g ”END”, is sometimes called a pseudo-
operation code on pseudo-opcode
2. Interpreter

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 Translates the source program statements into machine
code
 Includes linkage for closed subroutines
 Allcocates areas of main storage
 Generates the object program on cards, tape and disc as
required
 Produces a printed listing of the source and objected
programs when required
 Tabulates a lish of errors found during compilation
- Compilers are commonly used for the translation of HLL program
- Compiler translates the whole of the HLL source program into a machine
code object program prior to the program being loaded into main memory
and executed
- If a compiler is used, the same program need only be translated once
 Stages of compilation
 lexical analysis
 systatical analysis
 code generation

Chapter 7: SOFTWARE.
Question 1. Application software?
- Application software comprises the programs that are written specifically
to achieve resulting appertaining to the company’s activities
- Application software comes from two source
 They produce by themselves

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- Support given depends on stability and professionalison of the vendor
- User are required to comply with the owner’s regulations
Question 2. Utility software?
- Certain processing is common to a high proportion of computer users, and
so utility software has been created to cater for this need
- Utility software is intended to be sufficiently flexible to meet most user’s
requirements and is tailored to meet their precise needs by means of
parameter entered prior to use
- Some of the utility programs described below may be incorporated into the
OS that is used with a particular computer
 File conversion: this convers the transference of data from
any medium to any other
 File copying: an exact copy of a data set is made on to
another lot for the same type of storage medium
 File reorganisation: direct access, files over flow records
are stored in designed blocked, this is acceptable up to a
point but from time it si necessary to reorganise the file so
as to remove the overflow
 File maintenance(amendment): this procedure involves the
straightforward insertion and deletion of records into or
form sequential files
 Sorting: is frequently necessary in order to arrange a set of
records into a certain sequence based on their key values
 Dumping routines: a dump routine is used in confunction

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