Computer with self configuring video circuitry

• US 5,257,350 A
• Filed: 12/13/1991
• Issued: 10/26/1993
• Est. Priority Date: 08/10/1989
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Bailey, Robert L., Howard, Brian D.
• Primary Examiner(s): Harkcom, Gary V.
• Assistant Examiner(s): JANKUS, ALMIS R
• Application Number:
  US07/807,611
• Time in Patent Office: 683 Days
• Field of Search: 395/127-129, 395/162, 395/163, 395/153, 395/154, 364/DIG. 1, 364/DIG. 2, 328/60-63
• US Class Current: 345/501
• CPC Class Codes: G09G 1/16 the pattern of rectangular co-ordinates extending over the whole area of the screen, i.e. television type raster
• CPC Class Codes: G09G 1/285 Interfacing with colour displays, e.g. TV receiver
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 2370/042 for monitor identification

Abstract

A computer having a video circuit which is configured by a monitor identification signal is described. The self-configuring circuit permits connection to a variety of monitor types without the need for a separate video card or other dedicated circuitry compatible with the specific monitor type. The computer automatically senses the type of the monitor to which it is coupled, then configures its internal circuitry to provide compatible video signals to the monitor. The invented computer includes a central processing unit (CPU) for executing a program to provide video data for display on the monitor. The data is stored in the computer in a random-access memory (RAM). The monitor provides an identification signal to the video circuit which then provides both the appropriate video timing signals and the video data to the monitor for display thereon. The identification signal is used to configure the video circuitry in accordance with the requirements of the monitor.

Claims

1. A computer configurable to a plurality of monitors, each monitor having a different set of monitor display parameters required for its use, said computer for displaying video data on said plurality of monitors, said computer comprising:

a central processing unit (CPU) for executing a program to provide video data for display on a given one of said monitors;

a random-access memory (RAM) for storing said video data;

means for transferring said video data from said RAM to said given one monitor for display thereon, said given one monitor providing a signal which identifies said given one monitor;

a register means for decoding said signal and selecting a set of monitor parameters associated with said given one monitor;

a frequency source providing a plurality of frequency references;

dot clock generator means for producing a dot clock signal from said plurality of frequency references in response to said monitor signal, said dot clock signal being compatible with said given one monitor;

video circuitry for producing video display signals to said given one monitor, such that said circuitry being configured by said monitor signal such that video display signals are compatible with said given one monitor.

2. The computer according to claim 1 wherein said set of monitor parameters includes the number of bits per pixel of said video data provided by said transfer means to said display.

3. The computer according to claim 2 wherein said dot clock generator means is programmable.

4. The computer according to claim 2 wherein said dot clock generator means comprises a multiplexer having a plurality of inputs coupled to said plurality of frequency references, and an output for providing said dot clock signal.

5. The computer according to claim 4 further comprising a video digital-to-analog convertor for receiving said video timing signals and said video data and for producing red, green and blue color information therefrom to said monitor.

6. A computer which provides video signals for display on a plurality of monitors, each monitor having a different set of monitor display parameters for its use, each of said monitors providing a signal which identifies the monitor, said computer comprising:

storage means for storing monitor parameter information associated with each of said monitors used for displaying video data;

selecting means coupled to said storage means for selecting a set of monitor parameters associated with said monitor in response to said signal;

dot clock generator means coupled to said storage means for producing a dot clock signal associated with said monitor;

video display circuitry coupled to said storage means and said clock generating means for producing video display signals associated with said monitor, said video timing signals and said video data being coupled to said monitor.

7. The computer of claim 6 further including a video digital-to-analog convertor for receiving said dot clock signal, said video timing signals and said video data, and for producing red, green and blue color display information to said monitor.