Method and system for transmitting data from a unidirectional transmitter to a receiver

A display device operation as a unidirectional transmitter for transmitting data to a receiver, comprising:

• means for determining a maximum baud rate for the display device;
• means for selecting a baud rate for the display device equal to about the lesser of the maximum baud rate for a known receiver and the maximum baud rate for the display device;
• and
• means for displaying a synchronization signal at the selected baud rate for the display device, the synchronization signal comprising a synchronization parameter for receipt by a receiver configured to measure baud rate for the display device based on the synchronization parameter by determining a time differential between a first scan line and a second scan line of the synchronization signal and to set the baud rate of the receiver to match the baud rate of the display device.

A receiver for receiving data from a display device operating as a unidirectional transmitter, comprising:

• means for receiving a synchronization signal from the display device;
• means for measuring a synchronization parameter from the synchronization signal by determining a time differential between a first scan line and a second scan line of the synchronization signal;
• and
• means for selecting a baud rate for the receiver based on the synchronization parameter.

A computer-readable medium storing a program module comprising instructions which, when executed by a computer system comprising a processing unit, a memory storage device, and a user input/output system including a CRT, cause the computer system to perform the steps of:

• retrieving configuration parameters associated with the CRT from the memory storage device;
• computing the maximum baud rate at which the CRT may be operated as a unidirectional transmitter;
• selecting a baud rate for the CRT equal to about the lesser of the maximum baud rate for a known receiver and the maximum baud rate at which the CRT may be operated as a unidirectional transmitter;
• and
• displaying a synchronization signal on the CRT at the selected baud rate for operating the CRT, the synchronization signal comprising a synchronization parameter for receipt by a receiver configured to measure baud rate for the CRT based on the synchronization parameter by determining a time differential between a first scan line and a second scan line of the synchronization signal and to set the baud rate of the receiver to match the baud rate of the CRT.

A computer-readable medium storing a program module comprising instructions which, when executed by a receiver comprising a processing unit, cause the receiver to perform the steps of:

• receiving a synchronization signal comprising alternating illuminated and non-illuminated horizontal scan lines on a CRT;
• measuring a synchronization parameter comprising the time between the display of two consecutive illuminated horizontal scan lines on the CRT;
• selecting a baud rate for the receiver based on the synchronization parameter;
• and
• indicating a lock condition upon selecting the baud rate for the receiver.

In a receiver comprising a processing unit, a memory storage device, and a photo-detector, a method for receiving data displayed on a CRT, comprising the steps of:

• receiving a synchronization signal displayed on the CRT via the photo-detector, the synchronization signal comprising a plurality of bits wherein each bit comprises a line displayed on the CRT;
• measuring a synchronization parameter from the synchronization signal;
• selecting a baud rate for the receiver based on the synchronization parameter;
• indicating a lock condition upon selecting the baud rate for the receiver;
• receiving a data segment displayed on the CRT, the data segment comprising a plurality of bits wherein each bit comprises a line displayed on the CRT;
• receiving an integrity check parameter displayed on the CRT, the integrity check parameter comprising a plurality of bits wherein each bit comprises a line displayed on the CRT;
• determining whether the data segment was properly received based on the integrity check parameter;
• and
• if the data segment was not properly received, indicating an error condition.

In a computer system comprising a processing unit, a memory storage device, and a user input/output system including a CRT, a method for transmitting data from the CRT, comprising the steps of:

• retrieving the number of scan lines per frame, and the vertical refresh rate, of the CRT from the memory storage device;
• computing the maximum baud rate at which the CRT may be operated as a unidirectional transmitter;
• selecting a baud rate for the CRT equal to about the lesser of the maximum baud rate for a known receiver and the maximum baud rate at which the CRT may be operated as a unidirectional transmitter;
• displaying a synchronization signal on the CRT at the selected baud rate for the CRT, the synchronization signal comprising a plurality of bits wherein each of a plurality of the consecutive horizontal scan lines displayed on the CRT comprises a bit of the synchronization signal, the synchronization signal comprising a synchronization parameter for receipt by a receiver configured to measure baud rate for the CRT based on the synchronization parameter and to set the baud rate of the receiver to match the baud rate of the CRT;
• displaying a data segment on the CRT, the data segment comprising a plurality of bits wherein each of a plurality of the consecutive horizontal scan lines displayed on the CRT comprises a bit of the data segment;
• and
• displaying an integrity check parameter on the CRT denoting an amount of data comprising the data segment, the integrity check parameter comprising a plurality of bits wherein each of a plurality of the consecutive horizontal scan lines displayed on the CRT comprises a bit of the integrity check parameter.