Browse Prior Art Database

A Simple Diagnostic Screen for a Graphics Display

IP.com Disclosure Number: IPCOM000103447D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 47K

Publishing Venue

IBM

Related People

Smith, TJ: AUTHOR [+2]

Abstract

Disclosed is a test pattern concept for a color graphics display. The test pattern allows a customer engineer or service representative to visually check much of the logic required to support a graphics display workstation. This is accomplished by placing two simple patterns on the screen side by side (see figure). The key is that these patterns are created with different logic.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

A Simple Diagnostic Screen for a Graphics Display

      Disclosed is a test pattern concept for a color graphics
display.  The test pattern allows a customer engineer or service
representative to visually check much of the logic required to
support a graphics display workstation.  This is accomplished by
placing two simple patterns on the screen side by side (see figure).
The key is that these patterns are created with different logic.

      The pattern of reverse image color bars on the left is created
through the use of field attributes.  The logic in the CRT controller
manipulates the video line when a field attribute is detected.  The
pattern on the left is a string of blanks preceded with a reverse
image color attribute, and ending with a normal attribute.  The
result is the stack of seven different color bars.

      The pattern of reverse image color bars on the right is created
by drawing horizontal lines with a graphics processor.

      The two halves look the same for a display that is functioning
properly.  If, however, the vector processor, bit map planes, color
look-up tables, or color video lines are not functioning properly,
the two halves will not be identical.  A trained service
representative will know immediately where to look to resolve the
problem.

      The microcode to display such a screen can be available in
resident storage, and accessible via a simple keystroke sequence.
This display pattern takes a small amount of mi...