Abstract: A method and apparatus is disclosed which provides for controlling a rate of transmission of information over a serial communications channel. Each unit of information transmitted has associated therewith a start bit and a plurality of stop bits. The number of stop bits is adjusted to provide a desired effective channel transmission rate. In an alternate embodiment the communication channel is held in a selected state subsequent to the transmission of each unit of information for a selected period of time prior to the transmission of a following unit of information. Consequently, while the actual rate of transmission of information over a communication channel remains constant, an effective rate of transmission may be varied in accordance with a desired rate of transmission.

Abstract: A variable size and position dialog area or alphanumeric area is provided for the screen of a computer terminal in response to a single line of data from a data bus, containing the numerical indication of the initial line of a plurality of lines of alphanumeric information to be displayed and the numerical indication of the last line of a plurality of lines of alphanumeric information to be displayed. The numerical indications are successively loaded to a state machine operating as a counter which disables the alphanumeric display during a first counting operation and enables the alphanumeric display for the duration of a second counting operation.