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Color Bar Generator - Videosoft - Atari 2600    Manual Scan icon HTML Manual Box Scan icon  

Color Bar Generator by Video Soft


Jerry Lawson
Steve Yeung
Daniel McElroy

Video Soft, Inc.
1700 Wyatt Dr. Suite 10
Santa Clara, CA 95035

(408) 980-9211

Revision 1
February 6, 1984

The test pattern cartridge contains 15 displays that can be used to check or align most adjustments for a black and white or color television. One pattern is also included to check the alignment of the color generation circuitry on the Atari VCS ™ console circuit board. A 1kHz and 3kHz tone can be selected with the DIFFICULTY SWITCHES, and the patterns can be selected by scrolling forward or backwards through the list via the GAME SELECT or GAME RESET console switches.

* Title page and VCS color adjustment pattern
* Color bar pattern
* Grey scale pattern
* Cross hatch pattern
* Dot pattern
* Vertical lines
* Horizontal lines
* Center cross
* Circle pattern
* Wide vertical bars
* Window pattern
* White screen
* Red screen
* Green screen
* Blue screen

TITLE PAGE - contains the copyright notice "copyright � 1983 Video Soft", indicating that this program is protected under Title 17 United States Code. This screen also contains the color adjustment pattern for the Atari VCS ™ color generation circuits. The VCS generates audio and video signals using digital electronics. The color phase angles are generated by delaying the color signal until the desired phase angle is selected. An adjustment potentiometer is placed on the VCS console circuit board to adjust the 360 degree delay so that it is the same as 0 degrees. Although we do not recommend that you void any warranty on your game console, the potentiometer (the only one) can be adjusted so that the top half of the colored box is as close to the same color as the bottom half. The color generation circuits can then correctly produce colors from 0 to 360 degrees.

COLOR BAR PATTERN - gives a close approximation to the NTSC standard color bar. The top colors are gray, yellow, cyan, green, magenta, red, blue, and black. The bottom colors are a very dark green, white, blue, and black.

GREY SCALE PATTERN - produces eight shades across the screen going from white to black. This pattern can be used to check that the television can reproduce uniform changes in the luminance amplitude. The brightness and contrast can be adjusted so that all bars are showing across the screen. NOTE: it is not possible to turn off the color burst signal on the game console, even with the COLOR/BLACK-WHITE switch. Some color may creep into pictures which should have only a black and white display.

CROSS HATCH PATTERN, DOT PATTERN, VERTICAL LINES, HORIZONTAL LINES, and CENTER CROSS - are very useful for checking vertical and horizontal linearity
on any television, and are also useful for checking and aligning convergence on a color television.

CIRCLE PATTERN - is used to adjust the vertical size and linearity. If the vertical size and/or linearity are out of adjustment, the cycle could appear as an egg instead of being round.

WIDE VERTICAL BARS - can be used to test for smearing or fading of the video signal. The bars should appear as completely white and black bars.

WINDOW PATTERN - should appear as a white window in a completely black background. If the black background changes between black and gray at the top or bottom of the window, the DC coupling or DC restoration between the video amplifier and the picture tube is not functioning correctly.

WHITE SCREEN - is used to adjust the color circuits to produce a white screen on a color television.

RED SCREEN - is most useful in adjusting color purity. If the screen is not completely red, (such as other colors around the edges), the television should be degaussed. If degaussing does not cure the problem, the color purity magnets will probably need adjustment.

BLUE SCREEN, GREEN SCREEN - displays blue or green screens.