I've actually posted about this on another forum, but it's just too interesting not to share.
I recently stumbled across an early 1965 report on a study into hard landing what amounts to a digital camera on Mars in either 1969 or 1971.
The lander was designed to take a single (250000 bit (My estimation)) picture and transmit that image back to Earth.
See:
Study Of A High Resolution Facsimile Camera System Experiment On The Surface Of The Planet Mars