Operating system independent method and apparatus for graphical remote access

A method of transmitting to a remote location video graphics data stored in memory, comprising:

• dividing the memory into a number of storage blocks containing multibit color pixel values;
• reading contents of a first storage block and of at least one subsequent storage block;
• condensing the multibit color pixel values into 6-bit red-green-blue color pixel values;
• comparing the contents of the first storage block to successive subsequent storage blocks on the basis of the 6-bit pixel values;
• developing a repeat command based on how many consecutive subsequent blocks have the same contents as the first storage block;
• and
• transmitting the 6-bit values of the first storage block together with the repeat command.

A computer system for communicating with a remote console, comprising:

• a video graphics controller having a frame buffer to store multibit pixel values for display,
• a communications device;
• and
• a processor coupled to the video graphics controller and the communications device, the processor configured to:
• divide the frame buffer into rows of storage blocks;
• periodically read storage blocks of the frame buffer, change the multibit pixel values to lower number bit values to determine whether the stored contents of any of the storage blocks that have been read have changed since a previous reading, and for storage blocks having changed contents, store the lower number bit values in a transmit buffer;
• and
• transmit the lower number bit values of the contents of the changed blocks of a row from the transmit buffer to the remote console via the communications device for updating a display at the remote console.

A computer system for enabling display of graphics mode data on a remote console, the computer system having a processor controlled by an operating system, the computer system comprising:

• a video graphics controller having a frame buffer including storage blocks to store multibit pixel values;
• a communications device;
• and
• an independent processing means coupled to the video graphics controller and the communications device and configured to operate independently from the operating system, the independent processing means configured to:
• read multibit pixel values stored in blocks of the frame buffer and convert the multibit pixel values in each read block to corresponding lower number bit values;
• determine if the contents of a frame buffer block that has been read has changed from a previous reading of the contents of that block;
• and
• transmit via the communications device for updating a display at the remote console, the lower number bit values of each frame buffer block that has been read and for which the contents were determined to have changed from said previous reading.

A method for remotely displaying graphics mode data of a computer system on a remote console, the computer system having a processor controlled by an operating system, a video graphics controller having a frame buffer storing multipixel values representing video data for display, a communications device, and an independent processing means coupled to the video graphics controller and the communications device and configured to operate independently from the operating system, the method performed by the independent processing means comprising:

• periodically reading multipixel values stored in a plurality of blocks of said frame buffer;
• for each frame buffer block that is read condensing the multibit pixel values to lower number bit values;
• computing a current signature code for each block that is read, based on the contents of that block;
• comparing the signature code for each block that is read to a previously computed signature code corresponding to that block to determine if that frame buffer block has changed;
• and
• transmitting to the remote console via the communications device the lower number bit values of each frame buffer block that has changed, and updating a display at the remote console on the basis of the transmitted frame buffer blocks.

A computer system for enabling display of graphics mode data on a remote console, the computer system having a system processor controlled by an operating system, the computer system comprising:

• a video graphics controller having a frame buffer including storage blocks to store multibit pixel values,
• a monitor coupled to said video graphics controller,
• a communications device;
• and
• a processor coupled to the video graphics controller and the communications device and operable independently from the operating system to:
• read multibit pixel values stored in blocks of the frame buffer, convert the multibit pixels values in each read block to corresponding reduced number bit values, and compute a current signature value code corresponding to the contents of that block;
• compare the current signature value code of each block that has been read to a previously stored computed signature value code for that block;
• for blocks that have been read that have different current and previously computed stored signature value codes:
• (a) update the previously stored signature code by replacement with the current signature value code, and
• (b) transmit via the communications device for display at the remote console, the reduced number bit values representing the contents of those blocks.

A method for monitoring display data stored in memory at a first location for updating a display at a remote location, comprising:

• dividing a display memory into rows of blocks, the blocks storing multibit pixel values;
• periodically reading multibit pixel values stored in blocks in each of the rows;
• for each block that is read condensing the multibit pixel values to reduced bit number values;
• computing a current signature code for each block that is read based on the reduced bit number values;
• comparing the current signature code for each block that is read to a previously stored computed signature code corresponding to that block;
• for blocks that are read having different current and previously computed signature codes, (a) updating the previously stored signature codes by replacement with the corresponding current signature codes, and (b) transmitting over a communication link to the remote location said reduced bit number values.

A method for monitoring display data stored in memory at a first location for updating a display at a remote location, comprising:

• dividing a display memory into rows of blocks, the blocks storing multibit pixel values;
• periodically reading multibit pixel values stored in blocks in each of the rows;
• for each block that is read condensing the multibit pixel values to reduced bit number values;
• computing a current signature code for each block that is read based on the reduced bit number values;
• comparing the current signature code for each block that is read to a previously stored computed signature code corresponding to that block;
• for blocks that are read having different current and previously computed signature codes, (a) updating the previously stored signature codes by replacement with the corresponding current signature codes, and (b) storing the corresponding reduced bit number value blocks in a transmit buffer, and after reading each row, transmitting said reduced bit number value blocks from the transmit buffer over a communication link to the remote location and updating a display at said remote location on the basis of the transmitted blocks.