Page 59 - DCAP507_SYSTEM_SOFTWARE

Unit 3: Machine Structure and Assembler Basic Functions

3.3 Machine Level Language (1940-1950) Notes

Computer can understand binary codes (i.e., 1, 0) only. So the instructions given to the computer
can only be in 1 or 0. The language which contains binary codes is called machine level language.

A typical machine level language instruction essentially contains two parts:
(a) Operation part : Specifies what is to be performed.
(b) Address part : Specifies the location of data to be manipulated.

Writing programs in machine level language was a tedious task as it is difficult for human
beings to remember all the binary codes.

Did u know? What are high level languages?
A programming language such as C, FORTRAN, or Pascal that enables a programmer to
write programs that are more or less independent of a particular type of computer. Such
languages are considered high-level because they are closer to human languages and
further from machine languages. In contrast, assembly languages are considered low-
level because they are very close to machine languages.

Advantages

(a) Machine level instructions are directly executable.
(b) Machine level language makes most efficient use of computer system resources like storage,
register, etc.
(c) Machine language instructions can be used to manipulate individual bits.

Disadvantages

(a) As machine level languages are device dependent, the programs are not portable from
one computer to another.
(b) Programming in machine language usually results in poor programmer productivity.
(c) Programs in machine language are more error prone and difficult to debug.
(d) Computer storage locations must be addressed directly, not symbolically.
(e) Machine language requires a high level of programming skills, which increases
programmer training costs.

Self Assessment

Fill in the blanks:
13. Machine language instructions can be used to manipulate ………………….. bits.

14. …………………….. in machine language are more error prone and difficult to debug.

3.4 Assembly Language (1950-1958)

Assembly languages are also known as second generation languages. These languages substitute
alphabetic symbols for the binary codes of machine language.

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