In a

bulletin board system A bulletin board system (BBS), also called a computer bulletin board service (CBBS), is a computer server running list of BBS software, software that allows users to connect to the system using a terminal program. Once logged in, the user perfor ...

(BBS), a door is an interface between the BBS software and an external application. The term is also used to refer to the external application, a

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

that runs outside of the main bulletin board program. Sometimes called ''external programs'', doors are the most common way to add games, utilities, and other extensions to BBSes. Because BBSes typically depended on the telephone system, BBSes and door programs tended to be local in nature, unlike modern Internet games and applications. From the 1990s on, most BBS software had the capability to "drop to" doors. Several standards were developed for passing connection and user information to doors; this was usually done with "dropfiles", small binary or text files dropped into known locations in the BBS's file system. Most doors were responsible for operating the

serial port A serial port is a serial communication Interface (computing), interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in Pa ...

or other communications device directly until returning control to the BBS. Later development of

FOSSIL A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

drivers have allowed both BBSes and their doors to communicate without being responsible for direct operation of the communications hardware.

Door games

A major use of doors is for ''door games'':

computer games A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...

played on the BBS. These games included strategy games such as ''

TradeWars 2002 A trade war is an economic conflict often resulting from extreme protectionism, in which states raise or implement tariffs or other trade barriers against each other as part of their commercial policies, in response to similar measures imposed ...

'', ''Food Fight!'', ''Solar Realms Elite'', ''Space Dynasty'', Usurper, and ''Barren Realms Elite''. There were also

role-playing game A role-playing game (sometimes spelled roleplaying game, or abbreviated as RPG) is a game in which players assume the roles of player character, characters in a fictional Setting (narrative), setting. Players take responsibility for acting out ...

s (RPG), often derived from earlier email-based games—examples include

Seth Robinson Robinson Technologies is a Japanese video game developer founded by Seth Robinson. The company produced the BBS door games '' Legend of the Red Dragon'', ''Planets: The Exploration of Space'' and '' Growtopia'', an experimental multiplayer cr ...

's ''

Legend of the Red Dragon ''Legend of the Red Dragon'' (''LORD'') is a text-based online role-playing video game, released in 1989 by Robinson Technologies. ''LORD'' is one of the best known door games. The player's goal is to improve their skills in order to defeat t ...

'', popular dystopian RPG: ''Operation: Overkill,'' and ''Mutants!''. BBSes often published high scores, encouraging players to beat others. InterBBS leagues allowed users of different BBSes to compete against each other in the same game. A modern version of this known as BBSlink exists allowing

sysop A sysop (, an abbreviation of system operator) is an administrator of a multi-user computer system, such as a bulletin board system (BBS) or an online service virtual community.Jansen, E. & James, V. (2002). NetLingo: the Internet dictionary. Ne ...

s to offer door games on their BBS which are hosted on a remote server, thereby increasing the user base of the game.

Other applications

While many of the most popular and memorable BBS doors have been games, numerous doors had non-entertainment applications such as user polls or the time bank, permitting users to time-shift their rationed BBS use. Frequently they act as a front-end to themed databases on subject such as astrology, numerology and fortune-telling, recipes, weather prediction, personal ads (sometimes with additional match-making functionality), classified ads and "for sale" listings (sometimes permitting auctions), BBS lists, and parting comments from the most recent BBS callers.

References

External links

Break Into Chat
- BBS door game wiki
BBS Archives
- Collection of BBS doors and related files
Dropfile Formats
{{BBS Bulletin board systems