The GEM character set is the

character set Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using digital computers. The numerical values tha ...

Digital Research Digital Research, Inc. (DR or DRI) was a company created by Gary Kildall to market and develop his CP/M operating system and related 8-bit, 16-bit and 32-bit systems like MP/M, Concurrent DOS, FlexOS, Multiuser DOS, DOS Plus, DR DOS ...

's graphical user interface

GEM A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, a ...

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the devel ...

platforms. It is based on

code page 437 Code page 437 (CCSID 437) is the character set of the original IBM PC (personal computer). It is also known as CP437, OEM-US, OEM 437, PC-8, or DOS Latin US. The set includes all printable ASCII characters as well as some accented letters (diac ...

, the original character set of the

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a tea ...

, and like that set includes

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

codes 32–126, extended codes for accented letters (

diacritics A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacriti ...

), and other symbols. It differs from code page 437 in using other

dingbat In typography, a dingbat (sometimes more formally known as a printer's ornament or printer's character) is an ornament, specifically, a glyph used in typesetting, often employed to create box frames, (similar to box-drawing characters) or as ...

s at code points 0–31, in exchanging the

box-drawing character Box-drawing characters, also known as line-drawing characters, are a form of semigraphics widely used in text user interfaces to draw various geometric frames and boxes. Box-drawing characters typically only work well with monospaced fonts. ...

s 176–223 for international characters and other symbols, and exchanging code point 236 with the symbol for line integral. However, GEM is more similar to

code page 865 Code page 865 (CCSID 865) (also known as CP 865, IBM 00865, OEM 865, DOS Nordic) is a code page used under DOS in Denmark and Norway to write Nordic languages (except Icelandic, for which code page 861 is used). Code page 865 differs from code pa ...

because the codepoints of Ø and ø match the codepoints in that codepage. The

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...

-based GEM adaptation for the Atari ST family of computers utilized the similar Atari ST character set. It has swapped ¢ and ø and has also swapped ¥ and Ø (to match code page 437 more). It also has the ß (sharp s) at code point 158, reversed not sign (⌐) at code point 169 (as in code page 437), not sign (¬) at code point 170 (as in code page 437), ½ at code point 171 (as in code page 437), ¼ at code point 172 (as in code page 437), ¨ (diaeresis) at code point 184, ´ (acute) at code point 185, ĳ at code point 192, Ĳ at code point 193, Hebrew characters at code points 194-220, section sign (§) at code point 221, logical and at code point 222, infinity sign at code point 223, bullet (•) at codepoint 249, cubed sign (superscript three) at code point 254, the macron at code point 255, ATARI-specific characters at codepoints 5, 6, 7, 14, 15, 28, 29, 30, and 31, LED 0-9 at codepoints 16-25, and ə (Schwa) at codepoint 26. Codepoints 12, 13, and 27 are mapped to the C0 controls. A slight adaptation for Ventura Publisher is the similar

Ventura International Ventura International (or ''VENTURA_INT'') is an 8-bit character encoding created by Ventura Software for use with Ventura Publisher. Ventura International is based on the GEM character set, but ¢ and ø are swapped and ¥ and Ø are swapped so tha ...

character set, it has code points 0-31, 127, and 218-255 empty, and has swapped ¢ and ø and has also swapped ¥ and Ø (to match code page 437 more). In contrast to this, the GEM-derived file manager ViewMAX, which shipped with some versions of

DR DOS DR-DOS (written as DR DOS, without a hyphen, in versions up to and including 6.0) is a disk operating system for IBM PC compatibles. Upon its introduction in 1988, it was the first DOS attempting to be compatible with IBM PC DOS and MS-DO ...

as a DOSSHELL replacement, does not use the GEM character set, but loads its display fonts from DOS .CPI files depending on the system's current

code page In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some c ...

Character set

The following table shows the GEM character set. Each character is shown with a potential

Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, ...

equivalent, although some codes do not have a unique, single Unicode equivalent; the correct choice may depend upon context. Note that code point 20 (14₁₆) has an unfilled paragraph sign, and code point 188 (BC₁₆) has a filled paragraph sign.

References

{{Digital Research Character sets Computer-related introductions in 1985

Character set

See also

References