Abstract: An improved 3270 data stream architecture to eliminate data bytes in the 3270 data stream to improve line utilization and reduces network costs. First, a 6-bit increment option has been added to the addressing options for the buffer control orders to reduce the number of address bytes in the set buffer address (SBA) order, repeat to address (RA) order, and the erase unprotected to address (EUA) order. Second, a reduced Start Field (SF) and repeat to address (RA) orders are implemented with utilizing a modified Set Attribute (SA) order to designate the field attribute character and repeat character. The SF and RA orders following the SA order in the data stream are reduced in length. Third, a Modify Existing Format has been implemented which provides a means of modifying a format load that is currently in the format storage of the outboard device without having the host application program resend the entire format when only a small portion of the format needs to be modified.