The unit operates as a character generator, allowing 6 lines of 6 alphanumeric characters, or 3 lines of 6 taller characters to be typed onto an SSTV format screen. The message being typed in is displayed on the fast-scan monitor connected to the unit, whilst at the same time it is generated as a slow-scan signal and sent to the transmitter. A line cursor moves down the street at the slow-scan rate indicating which portion of the display is being transmitted. Complete on-screen cursor controls allow the operator to change any part of the text easily and immediately, there are also carriage return/line feed, delete character and clear screen commands. Further commands give the ability to transmit only certain lines of the text instead of the whole screen and also to reverse the display from the default mode of black characters on a white background to white on black. Also built into the terminal are a standard 6-bar grey-scale and a chequer-board pattern to assist in setting up equipment or for transmission.