- ANSI.SYS
ANSI.SYS is a
device driver in theDOS operating system that provides extra console functions throughANSI escape code s. It is partially based upon a subset of thetext terminal control standard proposed by the ANSI X3L2 Technical Committee on Codes and Character Sets (the "X3 Committee").Usage
To use ANSI.SYS under MS-DOS, a line is added to the
CONFIG.SYS (or CONFIG.NT under Windows NT based versions of Windows) file that reads:device=("drive:")("path")ANSI.SYS
where ("drive:") and ("path") are the drive letter and path to the directory in which the file ANSI.SYS is found.
Functionality
Once loaded, ANSI.SYS enabled codes that changed the colors of the cursor and characters on the screen, or enabled software programs to move the cursor up or down lines, enabled blinking text, and similar text graphics features. Using this driver, text could be displayed in 16 different colors ("foreground" colors), with 8 optional background colors. It also allowed for the changing of the video mode from standard 80x25
text mode to a number of different graphics modes (for example, 320x200, 640x200, 40-column text mode) depending on which video graphics card was installed.An interesting feature about ANSI.SYS was that it allowed for the remapping of any key on the keyboard in order to perform shortcuts or macros for complex instructions. This feature was also used by evildoers to create simple trojans out of text files called "ANSI Bombs" laced with nefarious keyboard remaps. A number of antivirus utilities were written to ensure that, for example, the F3
function key wasn't remapped to DEL *.* or FORMAT C: and the N-key (for no) wasn't remapped to Y.ANSI.SYS was extremely slow as it mapped to the BIOS calls. There were several replacements that directly mapped the video memory (similar to how most programs that did full-screen display worked on the IBM PC) that made console io useful. Typically these replacements also deleted the keyboard remapping functions and thus defused the "ANSI Bombs".
Occurrence
The file ANSI.SYS is a part of several
Microsoft operating systems, including:*
MS-DOS
*Windows 95
*Windows 98
*Windows NT
*Windows 2000
*Windows XP
*Windows Server 2003 (x86 versions)
*Windows Vista ANSI.SYS was required to run some software that used its cursor and color control functions. It could also be used to enable elaborate color codes in the
command.com prompt. These uses were overshadowed by the use of ANSI.SYS in BBSes; ANSI escape codes were used to enable BBSes to send elaborate text graphics more elaborate thanASCII art , and to control the cursor in ways that were used in a number ofonline game s and similar features.Features
There are some escape codes specific to ANSI.SYS.
See also
*
ANSI escape code External links
* [http://kb.indiana.edu/data/aamm.html Modifying the DOS prompt with ANSI.SYS]
* [http://web.archive.org/web/20070623224036/http://enterprise.aacc.cc.md.us/~rhs/ansi.html Guide to using ANSI.SYS]
* [http://ansilove.sourceforge.net Ansilove/PHP] A set of tools for converting ANSi/BiN/ADF/iDF/TUNDRA/XBiN files into PNG images
* [http://www.microvga.com/ansi-keycodes ANSI.SYS keyboard codes]
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