|
|
|
|
Page Views: 1,062 |
| Hashtags: #VisualBasic60 #ProgrammingforMicrosoftWindows |
| Optional preliminary material for this free online course in Visual Basic 6.0. |
| Estimated reading time: 5 minute(s) (1103 words) |
Where Did VB Come From?
While the Visual Basic language is simple and easy to learn, there are a few quirks in it that
are made much easier to understand if we know where the language came from.
For one thing, there were no such thing as calculators, and computers
were not widely used. The idea of a college buying one was still pretty
novel; and a question that was inevitably asked, was, "What department gets the
computer?"
"Well, what do computers do?"
"Well…they add numbers together…"
"Ah! Then, we'll give it to the Math department."
Consequently, all the early work on computers was done by mathematics majors,
who have influenced pretty much every aspect of computing ever since.
(I often wonder how different computer programming would be today, if the Art
departments had gotten computers first?)
In any case, the graduate math students at Dartmouth thought it would be
really great—"swell" was the term they used back then—if they could figure out a
way to make the calculating power of the computer available to the undergraduate
students, the ones with little interest in the computer. They conceived of
putting computer terminals all over the campus, with keyboards, so that anyone
interested could type in a math problem and get an answer.
Up to this time, the most popular language for addressing mathematics on a
computer was FORTRAN, which all the graduate students had learned. However,
writing a program in FORTRAN was complicated; it took taking an actual class to
learn. Requiring that of the undergraduate students kind of defeated the purpose
of the convenient terminals. So, the grad students invented a new
language, which they called BASIC (for Beginner's All-purpose Symbolic
Instruction Code).
FORTRAN did not start out as a block-structured language (one that uses
procedures), so BASIC didn't, either. Each line has a line number, and the line
numbers doubled as labels. At first there were no control structures: no
While or Loop statements at all. All conditional control was accomplished
via If and Goto statements. A typical sample of BASIC code might
look like this:
100 PRINT "Program starting"
110 INPUT H, W
130 IF H > 40 GOTO 400
140 PRINT "Paycheck is ";H*W;" with no overtime."
150 GOTO 500
400 V = H - 40
405 H = H - 40
410 PRINT "Paycheck is ";V*(W*1.5)+H*W;" with ";
420 PRINT V;" hours overtime."
500 PRINT "Program done!"
510 END
Considering that the results were many times more accurate than a math
student could get from his or her sliderule, it should be no surprise that
BASIC was a great success; with it quickly spreading to other colleges and
universities across the United States and Canada.
Enter the Microcomputer
A few years passed. Color television sets were new, and expensive. An
electronics firm was founded, Heathkit, that sent purchasers the parts of
a color TV, for the purchasers to assemble! "Learn electronics at home!" the
advertisements read.
So, when Intel invented the first microcomputer CPU (the 4004), a few
enterprising young men founded the Altair Computer Corporation, which was built
on the same principle: You order the parts, assemble them yourself, and voila!
You own a microcomputer.
Learning to solder transistors and ICs together was one thing; programming is
much harder. So, since the founders of Altair had learned BASIC in college, it
was only natural that they would use it as the command language for their
microcomputers.
Back in those pre-corporate-merger days, most businesses in the country were
small, Mom-and-Pop organizations. Pop was usually the shopkeeper, and Mom
usually did the books. So, Pop (more likely to be the hobbyist in those days)
would convince Mom to let him buy an Altair microcomputer. "As soon as it's
built," he'd tell her, "it will do your bookkeeping for you!"
Well, eventually Pop would have built the computer…then had to write
the accounting program he'd promised! …in BASIC. A language originally
intended for ten or fifteen line math problems was being used to write 5,000
line accounting systems, payroll programs, inventory systems, and more. The code
was, of course, completely unreadable to anyone but the one who wrote it.
Nevertheless, a lot of the small business computerization began with an Altair
computer, with BASIC implemented on a single ROM (Read-Only Memory)
chip.
When the IBM PC was introduced in 1981, it included a version of BASIC, again
burned into a ROM. Other companies quickly copied the computer's design, often
improving on it; but they couldn't include the copyrighted BASIC ROM. So,
a non-IBM version of the operating system, MS-DOS, included a software BASIC.
Microsoft then released an expanded, block-structured BASIC called
QuickBASIC; other language companies sold versions of their own. However, the
BASIC language suffered a setback with the release of Borland's Turbo Pascal: It
only cost $19.95, and was clearly a superior language for writing real programs.
BASIC languished, then, for several years, until Alan Cooper used it as the
basis of Visual Basic, which he promptly sold to Microsoft. While it was crude
compared to the Visual Basic of today, it was nevertheless easy-to-use (for
small programs) and unexpectedly became Microsoft's biggest language seller,
where it has remained ever since.
That first version of Visual Basic did not have a Data control,
user-defined objects, MDI (Multiple Document Interface) support, auto-completion
of keywords, or many other features we take for granted. Still, it changed the
face of computer programming, and has led the way in the design of integrated
development environments ever since.