Wednesday, July 29, 2009

Amber Screens

Raise your hand if you remember when computer displays came in three colors: green, white, or amber text, always on a black background. Since the beginning, the Windows shortcut to a command prompt came configured to display text in either white or green, and always on a black background. The Colors tab allows you to choose foreground and background colors from a palette of a paltry 16 colors, which includes some decent colors, none of which is amber.

Among the three basic color schemes, I favored amber text on a black background from the first time I saw a an amber monitor. I liked it because the contrast was much better than green letters on a black background. Indeed, it might be surprising to some, but I think the contrast is at least as good as white on black, and, under certain circumstances, it is better.

Figure 1 - The Original Green Screen

Figure 1 - The Original Green Screen

Figure 2 - White Text on Black

Figure 2 - White Text on Black

In those days, there was considerable variation in the actual colors displayed; some of the green screens were brighter than the one shown in Figure 1, above, and some of the white phosphor screens were less bright than the one shown in Figure 2, above.

I promptly replaced my green screen with an amber one, which I used until I started buying VGA color screens to run Microsoft Windows 3.0, around 1990. The occupational health authorities in some European countries came to the same conclusion, and began requiring amber screens in work places, beginning in about 1983.

Beyond the 16 Color Palette

One day recently, having grown tired of yellow text on a blue background, I paid a visit to the Colors tab on the Command Prompt shortcut property sheet, and discovered something that I had scarcely noticed. In the upper right corner of the page, there is a group of three spinner controls, labeled Red, Green, and Blue (See Figure 3, below.). Their values change to reflect the selected color from the sixteen color tiles spread across the middle of the property sheet, and it didn't take long for me to realize that they are the RGB color codes that map to the selected color.

Figure 3 - Colors Dialog Box, showing settings for Amber text

Figure 3 - Colors Dialog Box, showing settings for Amber text

Using the preview controls just above the three push buttons, I began playing with the RGB color values. It didn't take long to see that I could replace any of the sixteen colors with the color of my choice, and assign it to any of the four color properties of a Command Prompt window. Hence, as is the case with the colors in the Display control panel applet, you have a choice of 16,581,375 colors!

Figure 4, below, illustrates my new amber on black Command Prompt window.

Figure 4 - My Amber on Black Command Prompt window

Figure 4 - My Amber on Black Command Prompt window

I Want to Start in My Documents

While I was at it, I decided to change the Startup directory, which is, by default, %HOMEDRIVE%%HOMEPATH%, and resolves to C:\Documents and Settings\David in my user profile. As shown in Figure 5, below, I replaced the default Start In string with %USERPROFILE%\My Documents. Since %USERPROFILE% resolves to C:\Documents and Settings\David, the whole string resolves to C:\Documents and Settings\David\My Documents. Since the path string may contain embedded spaces, it is enclosed in quotation marks.

Figure 5 - Startup Directory

Figure 5 - Generic Startup Directory, pointing to My Documents

Because all paths are specified as environment variable substitution tokens, and the remaining settings are at their default values, this shortcut works on any installation of Microsoft Windows.

http://www.wizardwrx.com/FREEBIES/AmberCommandPrompt.ZIP is a complete command prompt shortcut, ready for use. The Command Prompt shortcut, Command Prompt.lnk, in AmberCommandPrompt.ZIP reflects the settings shown in Figure 3, for colors, and Figure 5, for startup directory.

Long live the Amber Screen!