Editing Lotus 1-2-3 (section)

==== {{anchor|3|3.1|3.1+|3.4|4|Home}}Protected Mode (80286+) ====
These editions of 1-2-3 for DOS were primarily written in [[C (programming language)|C]].
* Release 3 introduced the concept of 3D spreadsheets, utilized [[extended memory]], supported having multiple files open simultaneously, and required an 80286-based PC or higher. It also introduced support for the [[Lotus Multi-Byte Character Set]] (LMBCS).<ref name="Balaban_2001_LMBCS">{{cite web |title=Multi-Language Character Sets - What They Are, How To Use Them |author-first=Bob |author-last=Balaban |date=2001 |publisher=Looseleaf Software, Inc. |url=http://www.bobzblog.com/tuxedoguy.nsf/dx/multilanguage.pdf/$file/multilanguage.pdf |access-date=2016-11-25 |url-status=dead |archive-url=https://web.archive.org/web/20161125174612/http://www.bobzblog.com/tuxedoguy.nsf/dx/multilanguage.pdf/%24file/multilanguage.pdf |archive-date=25 November 2016 }}</ref><ref name="Lotus_1989_Compatibility"/> Introduced in March 1989.<ref name="umd123"/><ref name="NYT123-89"/><ref name="Balaban_2001_LMBCS"/><ref name="Walkenbach_2007_VBA"/> The test was performed with 16 MHz system with the [[Intel 80387SX|387SX-16]] math coprocessor using the mortgage payment schedule file resulting 33 seconds without math coprocessor and 10 seconds with it.<ref>[https://archive.org/details/199105imcpig Intel Corporation, "Intel Math CoProcessor Pocket Information Guide", CP1-334/0591/100K/DG LH, 1991, page 8]</ref>
* Releases 3.1 and 3.1+<ref name="Kamenz_1992_DB"/> added WYSIWYG capabilities, the ability to swap to disk allowing for larger files (up to 64 MB), and could be run as a DOS program under [[Windows 3.0]] and OS/2. Introduced in 1990.<ref>{{cite magazine |author-last=Walkenbach |author-first=John |title=Lotus 1-2-3, Release 3.1 Has Publishing-Quality Output |magazine=[[InfoWorld]] |date=1990-10-15 |volume=12 |issue=42 |pages=91–92, 96 |url=https://books.google.com/books?id=LjwEAAAAMBAJ&pg=PT78 |access-date=2015-01-12}}</ref>
* Release 3.4 added icons, improved performance, and enhanced graph capabilities, making it functionally similar to Release 2.4. Introduced in 1992.<ref>{{cite magazine |author-last=Walkenbach |author-first=John |title=Lotus updates, accelerates 1-2-3 for DOS |magazine=[[InfoWorld]] |date=1993-02-15 |volume=15 |issue=7 |pages=57, 60–61 |url=https://books.google.com/books?id=ujsEAAAAMBAJ&pg=PA57 |access-date=2014-10-29}}</ref>
* Lotus 1-2-3 for Home, 1992
* Release 4 was the last release for DOS. More an upgrade to Release 3.4 than in line with Release 3 for Windows, it contains an improved interface and new features, including Version Manager, a spell checker, context-sensitive help, and cell comments. Introduced in May 1994.<ref>{{cite magazine |author-last=Singh |author-first=Jai |title=Lotus Readies 1-2-3 Upgrade |magazine=[[InfoWorld]] |date=1994-05-16 |volume=16 |issue=20 |page=10 |url=https://books.google.com/books?id=nTgEAAAAMBAJ&pg=PA10 |access-date=2014-10-23}}</ref><ref name="Walkenbach_2007_VBA"/>