Editing QuickBASIC (section)

==History==
Microsoft released the first version of QuickBASIC on August 18, 1985 on a single 5.25-inch 360&nbsp;KB [[floppy disk]]. QuickBASIC version 2.0 and later contained an [[Integrated Development Environment]] (IDE), allowing users to edit directly in its on-screen text editor.

Although still supported in QuickBASIC, line numbers became optional. Program jumps also worked with named labels. Later versions also added control structures, such as multiline [[conditional (programming)|conditional statements]] and loop blocks.

Microsoft's "PC BASIC Compiler" was included for compiling programs into DOS executables.  Beginning with version 4.0, the editor included an interpreter that allowed the programmer to run the program without leaving the editor.  The interpreter was used to debug a program before creating an executable file.  Unfortunately, there were some subtle differences between the interpreter and the compiler, which meant that large programs that ran correctly in the interpreter might fail after compilation, or not compile at all because of differences in the memory management routines.<ref>[https://www.betaarchive.com/wiki/index.php/Microsoft_KB_Archive/45850 Microsoft Knowledge Base 45850: Memory Management in QuickBasic & Basic Compiler]</ref>

The last version of QuickBASIC was version 4.5 (1988), although development of the Microsoft BASIC Professional Development System (PDS) continued until its last release of version 7.1 in October 1990.<ref>QuickBASIC 4.5 was delivered on a set of five 360&nbsp;KB 5.25-inch DSDD floppy disks or three 720&nbsp;KB 3.5-inch DSDD floppy disks.  The three-disk version could also be installed from 1.2&nbsp;MB 5.25-inch or 1.44&nbsp;MB 3.5-inch DSHD disks.  To save costs, the files were compressed and later versions were shipped on just four 5.25-inch disks or two 3.5-inch disks.</ref>  At the same time, the QuickBASIC packaging was silently changed so that the disks used the same compression used for BASIC PDS 7.1.<ref>[http://support.microsoft.com/kb/65291 Microsoft Knowledge Base article 65291]</ref>  The Basic PDS 7.x version of the IDE was called QuickBASIC Extended (QBX), and it only ran on DOS, unlike the rest of Basic PDS 7.x, which also ran on OS/2.

QuickBASIC 4.5 was the subject of numerous books, articles, and programming tutorials, and arrived near the high-point of BASIC saturation in the PC marketplace. In 1989, Microsoft Press bundled the QuickBASIC Interpreter into a book-and-software learning system called ''[[Learn BASIC Now]]''. The product was priced at $39.95 and included a Foreword written by Bill Gates, who reported that BASIC was in active use by over four million PC users.<ref>{{cite book |last1=Gates |first1=Bill |last2=Halvorson |first2=Michael |last3=Rygmyr |first3=David |title=Learn BASIC Now |date=1989 |publisher=Microsoft Press |location=Redmond, WA |page=ix}}</ref>

The successor to QuickBASIC and Basic PDS was [[Visual Basic (classic)|Visual Basic]] version 1.0 for MS-DOS, shipped in Standard and Professional versions.  Later versions of Visual Basic did not include DOS versions, as Microsoft concentrated on Windows applications.

A subset of QuickBASIC 4.5, named [[QBasic]], was included with [[MS-DOS]] 5 and later versions, replacing the [[GW-BASIC]] included with previous versions of MS-DOS.  Compared to QuickBASIC, QBasic is limited to an interpreter only, lacks a few functions, can only handle programs of a limited size, and lacks support for separate program modules.  Since it lacks a compiler, it cannot be used to produce executable files, although its program source code can still be compiled by a QuickBASIC 4.5, PDS 7.x or VBDOS 1.0 compiler, if available.

QuickBASIC 1.00 for the [[Classic Mac OS|Apple Macintosh]] operating system was launched in 1988. It was officially supported on machines running [[System 6]] with at least 1&nbsp;MB of RAM.<ref>[http://support.microsoft.com/kb/31937 QuickBASIC for Macintosh system requirements]</ref>  QuickBASIC could also be run on [[System 7]], as long as 32-bit addressing was disabled. QuickBASIC programming was significantly different on the Macintosh, because the system offered a graphical user interface and an event-driven programming model.<ref>{{cite book |last1=Halvorson |first1=Michael |last2=Rygmyr |first2=David |title=Learn BASIC for the Apple Macintosh Now |date=1990 |publisher=Microsoft Press |location=Redmond, WA}}</ref>