User input required...

If you're old enough to have owned a home computer back in the 80's, chances are that you will have spent some time inputting program code from a listing - whether it be from Computer & Video Games magazine, or a computer book bought from W.H Smiths.
It was part of the computer culture, magazines were full of user submitted BASIC programs, that other readers could input into their own computer - usually coupled with hours of frustration, trying to find the bugs, and usually ended in despair, as the program ran, and you then realised it was actually "pants"!
Probably one of the most expensive typos, was the insertion of a full-stop, instead of a comma, in a FORTRAN program controlling the Marina 1 probe - resulting in the craft being destroyed.
The only program I can remember writing, was on Grand National day, and consisted of a list of the horses running that day, a very simple random number generator, and some hand-drawn graphics; as for animation - there's more movement on a corpse. After the program ran, I gave my dad a list of the first four horses, which he stuck in his pocket and ignored. Pity, as that was the only time, that I have picked the first four horses - bet he'd have won a good few quid! Still makes me chuckle :)
It was also customary to go into W.H Smiths, Menzies, Boots and Woolies, and quickly type a stupid program that spewed rather crude text all over the TV, then legging it, before being 'escorted' off the premises'.

The excerpt in the photograph is from "60 Programs for your Electron".