CIS133C - Introduction
- Instructor introduction:
Vicki Jonathan is a
Systems Analyst at
Consolidated Freightways Corp
- Student introductions
from quiz 1
- Class information:
Syllabus including prerequisites, text, grading, and lab hours.
Schedule including exam dates and due dates for lab assignments.
- Introduction to COBOL:
In the 1950’s, when computers were first used for problem solving, all programs were written in machine language. These instructions consist of a series of ones and zeros that represent on and off electrical states. Coding in machine language is very time consuming (costly), too easy for a human programmer to make mistakes, and machine language is machine dependent so the main reason for developing COBOL was to introduce a uniform, machine-independent computer programming language for business use.
Grace Murray Hopper (1906-92) is known as the "mother of COBOL". She was an American mathematician and retired rear admiral in the United States Navy who first conceived of compilers. She developed the first commercial high-level programming language, called FLOW-MATIC a major forerunner of COBOL. Common Business Oriented Language was first developed by the Conference of Data Systems Language (CODASYL) in 1960.
COBOL, a structured programming language, was originally developed with the first three main characteristics in mind but there are additional features of COBOL to consider ---
- machine independent - COBOL programs can be executed on many different types of computers w/little or no modification - AS400 to IBM, even PC to mainframe.
- easy to maintain - program maintenance is the process of making modifications to existing programs, most programming time is spent doing this, programs that are easiest to maintain will save time and money.
- self-documenting - the programming language instructions or code contain English-like words and phrases that pretty much spell out what the program is doing.
- uniquely organized - programs are divided into four standard parts called divisions.
- suited for commercial data processing - most business data processing requires input/output of large amounts of data and/or simple calculations.
- data is organized into records - each record contains a collection of data (example: one customer’s account number, name, address, balance owed, purchases, payments received).
- programs can process several different types of files - sequential, indexed sequential, relative.
- programs can read and write massive amounts of data using only a few statements.
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