C-Map Systems’ WriteGPS II is an intelligent GPS video overlay and typewriter. It’s a self-contained 9- to 24-volt, palm-sized unit that overlays video with GPS time, date, position coordinates, altitude, depth, and heading. It can convert Lat/Long GPS coordinates to all NAD27 and NAD83 zones. It accepts NMEA serial output available from most GPS receivers (including small handheld units), and a PC keyboard to function as a video typewriter. Pal and NTSC models are available.