Taken from Don Mitchell's page, including the signal in black-and-white:

http://www.mentallandscape.com/C_CatalogMars.htm

A descent vehicle released by Mars-3 became the first probe to land on Mars, but it only operated for about 20 seconds, returning some data and 79 scan lines of video. The image below right is reported to be a view of that signal. It should probably be rotated 90° since the Mars-3 cameras were of the same cycloramic design as Luna-9, scanning vertically. After extensive analysis, Soviet scientists report that it contains no information. It is not likely a view of the Martian horizon as some people have suggested.

Signal from Mars 3 Lander:

And on this page (scorll down just a bit to the Mars 3 section):

http://www.mentallandscape.com/V_Cameras.htm#Luna9

In 1971, Mars-3 was the first spacecraft to land on the red planet. Two cycloramic cameras were installed, as on Luna-13. Like the second generation lunar cameras, they had 500 × 6000 pixel resolution, and scanned at 4 lines per second.

Unfortunately, contact with the lander was lost after only returning 15 to 20 seconds of video from each camera. This fragmentary image of 79 scanlines has been reported to be featureless, despite extensive computer analysis by Soviet scientists. The plotter, shown above in a Soviet documentary on Mars-3, is drawing the video signal in horizontal strokes. The image is often misinterpreted as a view of the Martian horizon, but the cycloramic camera was transmitting vertical strokes, just as the Luna-9 camera did. Thus the image should be rotated 90°, and its interpretation is unclear.

Pen Plotter Displays Signal from Mars-3 Lander: