Visual BASIC 1

Introduction

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Computer processors only speak machine code

Assembly Language

• Assembly language was used as a short hand for machine code

• Early programs were very difficult to write and required in-depth knowledge of the processor

MOV R1, XMOV R2, YADD R1, R2MOV X, R1

High-Level Languages

• High Level Languages were developed to make programming easier

• Special programs called compilers converted these high level languages to machine code

Fortran

• FORTRAN was the first high level language

• Used by scientists and engineers to do calculations

• FORmula TRANslator

High Level Languages are machine independent

• High Level Languages can be independent of specific processors

• The same program can be re-compiled to work on different machines

• No need to learn a new language to program a new processor

C Compilerfor Mac

C Compilerfor PC

PC Machine Code

Mac Machine Code

C Program

Some languages were developed for specific purposes

• FORTRAN for scientific and engineering calculations

• COBOL for business and banking

• PROLOG for artificial intelligence

Other languages were designed to be used for general purposes

• BASIC: Beginners’ All Purpose Symbolic Instruction Code

• Pascal: named after Blaise Pascal

• C

Visual BASIC

• Visual Basic (VB) is a programming environment from Microsoft

• It is used to build applications that run on the Microsoft Windows operating system

Interfaces

In the beginning …

• Computers were programmed by re-arranging the connections of wires into sockets

• Output was lights and numbers

Punched Cards & Printers

• Eventually punched cards could be used as input

• Output was to printers

Monitors & Keyboard

• Computers started to look more like those we see today

• Terminals to a mainframe

• Monitor & keyboard• Command Line

Interface

Personal Computers

• Enough processing power to fit on a desk

• Monitor & Keyboard

• Command Line Interface

• MS-DOS

GUI & Mouse 1973

• The mouse was a very important development

• Xerox PARC’s Alto computer had a 3-button mouse, a bit mapped display, and windows

Xerox Star 1981

• Double-clickable icons

• Overlapping windows• Dialog boxes• 1024 x 768

monochrome display

1983 Apple Lisa

• Pull-down menus

• Popularized Graphical Interface

1984 Apple Macintosh

1990 Microsoft Windows 3.0

1995 Microsoft Windows 95

• Similar to the MS Windows we have today

Visual BASIC

Visual BASIC

• Visual BASIC takes care of all the Windows interface issues and allows the programmer to concentrate on more important things

Interface Controls

• VB provides controls that look and behave like standard MS windows interface elements

VB Interface Controls

• We will learn how to program these controls to make simple Windows applications