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Display Controller Set Up As a Function of Display Monitor Type, Display Jumper Settings And Amount of VRAM

IP.com Disclosure Number: IPCOM000101278D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 81K

Publishing Venue

IBM

Related People

Tyson, JS: AUTHOR [+2]

Abstract

Disclosed is a method which combines the display monitor type information, prioritized display jumper settings, and the amount of VRAM to search for a match in the Display Type Table to determine the appropriate parameters to be used to set up the display controller.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Display Controller Set Up As a Function of Display Monitor Type, Display Jumper Settings And Amount of VRAM

       Disclosed is a method which combines the display monitor
type information, prioritized display jumper settings, and the amount
of VRAM to search for a match in the Display Type Table to determine
the appropriate parameters to be used to set up the display
controller.

      The IBM X-Station is designed to handle a wide variety of
display monitors and formats.  Each time the IBM X-Station is powered
on, the software must automatically determine the appropriate
parameters to be used to set up the display controller.  The IBM
X-Station software combines the display monitor type information,
prioritized display jumper settings, and the amount of VRAM to search
for a match in the Display Type Table.  The Display Type Table
contains pointers to the appropriate parameters to be used to set up
the display controller.

      The display monitor type information is determined by the
monitor itself.  The display monitor connector contains pins which
identify to the attaching machine the monitor type.  This information
is present on all PS/2*-type display monitors.  The classical
approach for display controller set up would use only this
information to determine the appropriate display controller
parameters.

      The amount of VRAM is determined by the POST (Power On
Self-Test) RAM test.  For IBM X-Station, the VRAM size is one of the
following:  512K, 1M, or 2M bytes. The IBM X-Station POST does not
allow setting of intermediate values. The amount of VRAM generally
affects the depth of the screen format (the maximum number of bits
per pixels).

      The display jumper settings are used to augment the set up.
They add flexibility to design since, for a given display monitor
type and VRAM size, different display screen formats or set up
parameters can be selected.  The display jumper settings are
prioritized to allow inexact match of th...