Editing Turbo Pascal (section)

== History ==
[[Philippe Kahn]] first saw an opportunity for Borland, his newly formed software company, in the field of programming tools. Historically, the vast majority of programmers saw their workflow in terms of the edit/compile/link cycle, with separate tools dedicated to each task. Programmers wrote [[source code]] using a [[text editor]]; the source code was then compiled into [[object code]] (often requiring multiple passes), and a [[linker (computing)|linker]] combined object code with runtime libraries to produce an executable program.

In the early IBM PC market (1981–1983) the major [[programming tool]] vendors all made compilers that worked in a similar fashion. For example, the [[Microsoft Pascal]] system consisted of two compiler passes and a final linking pass (which could take minutes on systems with only floppy disks for secondary storage, even though programs were very much smaller than they are today). This process was less resource-intensive than the later [[integrated development environment]] (IDE). Vendors of software development tools aimed their products at professional developers, and the price for these basic tools plus ancillary tools like [[Profiling (computer programming)|profiler]]s ran into the hundreds of dollars.

Kahn's idea was to package all these functions in an integrated programming toolkit designed to have much better performance and resource utilization than the usual professional development tools, and charge a low price for a package integrating a custom text editor, compiler, and all functionality needed to produce executable programs. The program was sold by direct mail order for {{US$|link=yes|49.95}}, without going through established sales channels (retailers or resellers).<ref>{{cite web|url=https://archive.org/details/micro-cornucopia-magazine-1984-12/page/n63|title=Micro Cornucopia (December 1984)|date=December 1984}}</ref>

The Turbo Pascal compiler was based on the Blue Label Pascal compiler originally produced for the NasSys cassette-based operating system of the [[Nascom]] microcomputer in 1981 by [[Anders Hejlsberg]]. Borland licensed Hejlsberg's "PolyPascal" compiler core (''Poly Data'' was the name of Hejlsberg's company in Denmark), and added the user interface and editor. Anders Hejlsberg joined the company as an employee and was the architect for all versions of the Turbo Pascal compiler and the first three versions of Borland [[Delphi (software)|Delphi]].<ref name="tp10">{{cite web |url=http://edn.embarcadero.com/article/20693 |title=Antique Software: Turbo Pascal v1.0 |last=Intersimone |first=David |date=2000-02-01 |publisher=Embarcadero Technologies |access-date=2010-11-09 |archive-url=https://web.archive.org/web/20101221211755/http://edn.embarcadero.com/article/20693 |archive-date=2010-12-21 |url-status=dead}}</ref>

The compiler was first released as Compas Pascal for [[CP/M]], and then released on 20 November 1983<ref name=releasedates>{{cite web |url=https://community.embarcadero.com/blogs/entry/turbo-pascal-version-10--the-turbo-pascal-release-dates-39142 |title=Turbo Pascal version 1.0 - the Turbo Pascal release dates |access-date=2020-09-09  |archive-date=2017-04-24  |archive-url=https://web.archive.org/web/20170424061647/https://community.embarcadero.com/blogs/entry/turbo-pascal-version-10--the-turbo-pascal-release-dates-39142 |url-status=dead }}</ref> as Turbo Pascal for CP/M (including the [[Apple II]] fitted with a [[Z-80 SoftCard]], effectively converting the [[MOS Technology 6502|6502]]-based Apple into a CP/M machine, the Commodore 64 with CP/M cartridge, and the later [[DEC Rainbow]]), CP/M-86, and DOS machines. On its launch in the [[United States]] market, Turbo Pascal retailed for {{USD|link=yes|49.99}}, a very low price for a compiler at the time. The integrated Pascal compiler was of good quality compared to other Pascal products of the time.<ref name="Chapman 2006">{{cite book |last=Chapman |first=Merrill R. |year=2006 |title=In Search of Stupidity: Over 20 Years of High-Tech Marketing Disasters |publisher=Springer-Verlag |page=118 |url=https://books.google.com/books?id=8jntt5nZZ5UC&pg=PA118 |isbn=978-1-59059-721-7 |quote=Borland made its debut in the industry in a big way with the release of Turbo Pascal in November 1983. Turbo Pascal was a port to DOS and CP/M of Anders Hejlsberg's COMPAS Pascal, and it was released by Borland at a price that seemed amazing at that time: $49.95, about one-tenth the price of comparable products. |access-date=2015-12-13 |archive-url=https://web.archive.org/web/20160623183825/https://books.google.com/books?id=8jntt5nZZ5UC&pg=PA118 |archive-date=2016-06-23 |url-status=live}}</ref>

The Turbo name alluded to the speed of compiling and of the executables produced. The edit/compile/run cycle was fast compared to other Pascal implementations because everything related to building the program was stored in RAM, and because it was a [[one-pass compiler]] written in [[assembly language]]. Compiling was much faster than compilers for other languages (even Borland's own later compilers for C),{{Citation needed|date=March 2009}} and other Pascal compilers, and programmer time was also saved since the program could be compiled and run from the IDE. The execution speed of these [[COM file|COM]]-format programs was a revelation for developers whose only prior experience programming microcomputers was with [[Interpreter (computing)|interpreted]] BASIC or [[UCSD Pascal]], which compiled to [[p-code machine|p-code]] which was then interpreted at runtime.

Unlike some other development tools, Turbo Pascal disks had no [[copy protection]]. Turbo Pascal came with the "Book License": "You must treat this software ''just like a book'' ... [it] may be used by any number of people ... may be freely moved from one computer location to another, so long as there is no possibility of it being used at one location while it's being used at another."<ref>{{Cite web|url=https://groups.google.com/g/borland.public.delphi.non-technical/c/dDP138UWW6k?pli=1|title=The no-nonsense license|website=groups.google.com}}</ref>

=== Reception ===
Borland sold about 250,000 copies of Turbo Pascal in two years, which [[Bruce F. Webster]] of ''[[Byte (magazine)|Byte]]'' described as "an amazing figure for a computer language".<ref name="webster198508">{{cite news |last=Webster |first=Bruce F. |author-link=Webster, Bruce F. |date=August 1985 |url=https://archive.org/stream/byte-magazine-1985-08/1985_08_BYTE_10-08_Declarative_Languages#page/n361/mode/2up |title=Greetings and Agitations |work=Byte |page=355 |access-date=27 October 2013}}</ref> He reported six months later that the figure had risen to "more than 400,000 copies in a marketplace that had been estimated as having only 30,000 potential buyers".<ref name="webster198602">{{cite news |url=https://archive.org/stream/byte-magazine-1986-02/1986_02_BYTE_11-02_Text_Processing#page/n343/mode/2up |title=Programming Tool and the Atari ST |work=Byte |date=February 1986 |access-date=9 May 2015 |author=Webster, Bruce |page=331}}</ref>

[[Jerry Pournelle]] wrote in the magazine in February 1984 that Turbo Pascal "comes close to what I think the computer industry is headed for: well documented, standard, plenty of good features, and a reasonable price". He disliked the requirement to buy another license to distribute binaries, but noted that "it turns out not to be a lot more. Borland only wants another {{US$|long=no|100}}" atop the {{US$|long=no|49.95}} base price, and that "my first impression of Turbo is that it's probably worth {{US$|long=no|149.95}}. It looks to do everything [[Pascal/MT+|MT+]] ''with the Speed Programming Package'' does, and maybe even do it faster and better".<ref name="pournelle198402">{{cite news |url=https://archive.org/stream/byte-magazine-1984-02/1984_02_BYTE_09-02_Benchmarks#page/n113/mode/2up |title=Chaos Manor Gets Its Long-Awaited IBM PC |work=Byte |date=February 1984 |access-date=8 February 2015 |author=Pournelle, Jerry |page=113 |author-link=Jerry Pournelle}}</ref> Pournelle reported in July that Turbo 2.0's [[overlay (programming)|overlay]]s "[allow] you to write big programs". According to Kahn, IBM had refused to resell Turbo Pascal unless the price was at least {{US$|long=no|200}}; Pournelle noted that "Turbo is much better than the Pascal IBM sells", and unlike the latter was compatible with the [[IBM PCjr]].<ref name="pournelle198407">{{cite magazine |url=http://blog.modernmechanix.com/2011/11/07/the-west-coast-faire/ |title=The West Coast Faire |magazine=[[Byte (magazine)|Byte]] |date=July 1984 |access-date=8 November 2011 |author=Pournelle, Jerry |author-link=Jerry Pournelle |page=136 |archive-url=https://web.archive.org/web/20120128010050/http://blog.modernmechanix.com/2011/11/07/the-west-coast-faire/ |archive-date=2012-01-28 |url-status=dead}}</ref> Three ''Byte'' reviewers praised Turbo Pascal in the same issue. One reviewer said that because of dialect differences "Turbo is not really Pascal. But it's very useful". While cautioning that it was not suitable for developing very large applications, he concluded that Turbo Pascal "is well written, fun to use at times, and fast enough to make up for its few shortcomings ... it is a bargain that shouldn't be passed up". A second called the DOS version "without doubt, the best software value I have ever purchased", while a third said that Borland "deserves praise for" the "high-value" CP/M version.<ref name="wadlow198407">{{cite news |url=https://archive.org/stream/byte-magazine-1984-07/1984_07_BYTE_09-07_Computers_and_Video#page/n263/mode/2up |title=Turbo Pascal |work=Byte |date=July 1984 |access-date=23 October 2013 |author1=Wadlow, Tom |author2=Pierce, Al |author3=Bridger, Mark |pages=263–278 |type=review}}</ref>

Also in July 1984, ''[[Creative Computing]]'' favorably compared Turbo Pascal to what the reviewer described as mediocre and expensive Pascals from UCSD, IBM, and Microsoft. He reported converting code written in IBM Pascal in less than 30 minutes, and that "under IBM Pascal, the average program took two weeks to write. With Turbo Pascal, the average is now two days". While noting the .COM and 64 KB limitations, the reviewer approved of Turbo's close adherence to the Jensen and Wirth language standard. The documentation was, he wrote, of "above average readability" and superior to IBM Pascal's. "My only fear", the review concluded, was that "it is grossly underpriced, and I worry that people might fail to take it seriously".<ref name="blank198407">{{Cite magazine |last=Blank |first=George |date=July 1984 |title=Turbo Pascal; the best cost less. |url=https://www.atarimagazines.com/creative/v10n7/53_Turbo_Pascal_the_best_co.php |access-date=2025-03-15 |magazine=Creative Computing |page=53 |volume=10 |issue=7}}</ref> "Turbo Pascal is the Pascal to acquire", ''Computer Language'' in September said of version 2.0. Praising its speed, extensions including PC graphics and sound, documentation, ease of using overlays, and "highly standard syntax", the magazine recommended Turbo to both new and experienced programmers.{{r|rodman198409}} ''[[PC Magazine]]'' was similarly complimentary in November, stating that "nothing like Turbo Pascal has ever existed for PC-DOS before". It praised 2.0's low price, speed, stability, ease of implementing overlays, and unusually good documentation for a compiler, and noted the existence of many utilities for Turbo Pascal from other companies. The review stated that the IDE that simplified the edit-compile-run-debug loop made Turbo Pascal accessible, like BASIC, to new programmers.<ref name="duntemann19841113">{{cite news |url=https://books.google.com/books?id=-Ukz6hjZEA4C&pg=PA276 |title=Supercharged Turbo Pascal |work=[[PC Magazine]] |date=1984-11-13 |access-date=25 October 2013 |author=Duntemann, Jeff |page=276}}</ref> 

Pournelle in August 1985 called version 3.0 "a distinct improvement on the already impressive version 2" and said that the new book license "seems quite fair to me". He said that "Turbo Pascal has got to be the best value in languages on the market today", and that Borland led the industry in "delivering excellent products at reasonable costs".<ref name="pournelle198508">{{Cite magazine |last=Pournelle |first=Jerry |date=August 1985 |title=The West Coast Computer Faire |url=https://archive.org/details/byte-magazine-1985-08/page/n300/mode/1up?view=theater |magazine=Byte |pages=293–326 |access-date=2023-11-05}}</ref> Webster also praised 3.0, stating in August 1985 that Turbo Pascal "is best known for its small size, incredible compile speeds, and fast execution times". He noted that the software's quality and low price was especially surprising after the "[[JRT Pascal]] fiasco", and stated that even at the new higher {{US$|long=no|69.95}} price, it was "probably still the best software deal on the market".{{r|webster198508}} Despite finding what the magazine called "a serious bug" in 3.0, and decreased compatibility with [[PC clone]]s, ''Byte'' in February 1986 stated that "it is hard to avoid recommending Turbo to anyone who wants to program in Pascal", citing improved speed and graphic routines.<ref name="bridger198602">{{cite news |url=https://archive.org/stream/byte-magazine-1986-02/1986_02_BYTE_11-02_Text_Processing#page/n291/mode/2up |title=Turbo Pascal 3.0 |work=Byte |date=February 1986 |access-date=9 May 2015 |author=Bridger, Mark |page=281}}</ref> When reviewing four other Pascal compilers in December 1986, the magazine described Turbo Pascal 3.0 as "practical and attractive to programmers at all levels of expertise".<ref name="shammas198612">{{cite news |url=https://archive.org/stream/byte-magazine-1986-12/1986_12_BYTE_11-13_Graphics_Algorithms#page/n273/mode/2up |title=Pascal for the IBM PC |work=Byte |date=December 1986 |access-date=9 May 2015 |author=Shammas, Namir Clement |page=265}}</ref>

Besides allowing applications larger than 64 KB, ''Byte'' in 1988 reported substantially faster compiling and executing for version 4.0, and that although it did not maintain previous versions' "almost total" backward compatibility, conversion was fast and easy. The reviewer concluded, "I highly recommend Turbo Pascal 4.0 as an addition to any programmer's software repertoire".<ref name="banks198802">{{Cite magazine |last=Banks |first=Walter |date=February 1988 |title=Turbo Pascal 4.0 |url=https://archive.org/details/byte-1988_02/page/n180/mode/1up?view=theater |magazine=Byte |pages=153–156 |access-date=2023-10-01}}</ref>

''Byte'' in 1989 listed Turbo C and Turbo Pascal as among the "Distinction" winners of the Byte Awards. Citing their user interface and continued emphasis on speed, the magazine stated that "for rapid prototyping there's not much better".<ref name="byte198901">{{Cite magazine |date=January 1989 |title=The Byte Awards |url=https://archive.org/stream/byte-magazine-1989-01/1989_01_BYTE_14-01_PC_Communications_and_Annual_Awards_and_Digitizing_Tablets#page/n371/mode/2up |magazine=Byte |page=327}}</ref> In the same issue Pournelle again praised version 4.0 and 5.0 of Turbo Pascal. Citing ''[[Anacreon (computer game)|Anacreon]]'' as "a good example of how complex a program you can write in Pascal", and the many libraries from Borland and other developers, he wrote "I think it may well be the language for the rest of us".<ref name="pournelle198901">{{Cite magazine |last=Pournelle |first=Jerry |author-link=Jerry Pournelle |date=January 1989 |title=To the Stars |url=https://archive.org/stream/byte-magazine-1989-01/1989_01_BYTE_14-01_PC_Communications_and_Annual_Awards_and_Digitizing_Tablets#page/n137/mode/2up |magazine=Byte |page=109}}</ref>

Scott MacGregor of Microsoft said that [[Bill Gates]] "couldn't understand why our stuff was so slow" compared to Turbo Pascal. "He would bring in poor [[Greg Whitten]] [programming director of Microsoft languages] and yell at him for half an hour" because their company was unable to defeat Kahn's small startup, MacGregor recalled.<ref>{{cite book |last1=Wallace |first1=James |last2=Erickson |first2=Jim |title=Hard Drive: Bill Gates and the Making of the Microsoft Empire |year=1992 |publisher=[[John Wiley & Sons]] |isbn=0-471-56886-4 |page=[https://archive.org/details/harddrivebillgat00wall_0/page/277 277] |chapter=Growing Pains |chapter-url-access=registration |chapter-url=https://archive.org/details/harddrivebillgat00wall_0/page/277}}</ref>

=== Successors ===

By 1995 Borland had dropped Turbo/Borland Pascal and replaced it with the [[rapid application development]] (RAD) environment [[Borland]] [[Delphi (software)|Delphi]], based on Object Pascal. The [[32-bit computing|32]]- and [[64-bit computing|64-bit]] Delphi versions still support the more portable Pascal enhancements of the earlier products (i.e., those not specific to [[16-bit computing|16-bit]] code) including the earlier static object model. This language backwards compatibility means much old Turbo Pascal code can still be compiled and run in a modern environment today.

Other suppliers have produced software development tools compatible with Turbo Pascal. The best-known are [[Free Pascal]] and [[Virtual Pascal]].