The Viking orbiter was 'brainier' than its Mariner 9 counterpart. It had two 4096-word computers like the Mariner, but because of its greater imaging needs had a tape recorder capable of storing 55 television stills at 2.112 megabits per second-half a billion bits in total. 

The Viking computers were general-purpose; that is, they could be reprogrammed according to need. They were however preprogrammed with an automatic set of instructions in case communications links were lost.