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Text Mode User Interfaces
Text Mode User Interfaces
To make you appreciate what you have got.
In the beginning there was manual circuit wiring, then buttons, switches,
blinking lights, and punch cards. Then came teletype terminals (basically
printers with keyboards connected to a computer) followed by video display
terminals.
Video display terminals initially mimicd teletype terminals. They printed
streams of characters such as letters, numbers, and punctuation on the
display and scrolled the text up like a printer would. Characters were
already represented by numeric codes, so rather than keeping track of every
point of light on the screen the terminal could keep track of just the
character codes. The character codes that made up what was displayed on
the screen were stored in a very small amount of RAM (only a couple of
kilobytes usually) and the graphical patterns of each character were stored
in ROM.
RAM, ROM, and other integrated circuit chips were very expensive at
the time. Because a minimal amount of RAM was needed to store the text
as opposed to the larger amount needed to store graphics, and because manipulating
the text characters was faster, this was a very optimal way to display
video information at the time. Microcomputers and desktop computers quickly
adopted this method of displaying video.
The following are a just a few examples of text based applications:
To maintain compatibility with TTY / serial communications many applications
would reduce themselves to the lowest common denominator of text streams.
This type of environment is known as a "command line interface". A text
prompt appears and the user must type in a command. The problem with this
kind of interface is that there are often thousands of commands, each with
different options or parameters that must be specified as part of the command.
A user would either need to memorize all of these or constantly look them
up in a manual.
From a programming perspective, this kind of environment can be quite
powerful as it enables one to easily and quickly pull together many different
commands in a variety of ways.
A number of different types of games were possible in pure text mode.
This example is an interactive fiction game. The player is controlled by
a small vocabulary of english commands and the game responds with printed
descriptions of the actions and environment.
Sadly this kind of game is much too cerebral for people these days.
Friendlier command applications often offered users a visual menu of
options such as this one.
Often in applications like these, it was necessary to memorize numerous
keyboard commands.
Abandoning the concept of printing scrolling text and taking direct
control of the text screen allows even more powerful text based interfaces.
This is a screen shot of the Power Menu disk manager. A very useful
file management program. It is completely keyboard driven using the arrow
keys for navigation and a visual menu with keyboard shortcuts.
There are more DOS shells than I can list and there are hundreds, perhaps
thousands of file managers and menu systems that were used.
Depending on the hardware of the computer, the text interface may have
special text characters. For example the above screen shot has arrow characters
and line characters used to draw the directory tree. Some systems even
allow redefining the characters by the software. Such characters can be
very useful in making a good looking text mode user interface that even
rivals that of GUIs.
This is the MS-DOS Shell, another text based file manager. (Optionally
this program can actually run in a graphical mode but it displays the same
as text).
Text based applications can share many of the same visual elements as
GUIs, such as buttons, pull down menus, mouse pointers, text boxes, list
boxes, overlapping windows, and more.
The Norton Commander, another popular file manager.
This is the Microsoft Exchange client for DOS, a text based e-mail
program.
Visual Basic.... For DOS! This screen shot demonstrates more of the
controls used in GUIs that can exist in a text based environment.
It is even possible to browse the web in text mode. Here is a screen
shot of Lynx, a popular text mode web browser, displaying Slashdot. After
all, technically the web is just text with graphics occasionally inserted.
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