The National Museum of Computing reports it is working to refurbish what it believes is the last ICT 1301 in good enough shape to have a chance of working again.
The machine -- hardly a "desktop" unit with its 20-foot by 23-foot size -- had originally been used to produce exam results for students at the University of London in the 1960s.
"Before this time, computers were absolutely huge with valves and thousands of vacuum tubes and would get incredibly hot, making them difficult to house in a normal business," museum trustee Kevin Murrell told the BBC. "But this machine used transistors, which used very little power. That meant you could have more of them in the same space, you didn't need the complex cooling equipment and you wouldn't require the high power that earlier computers needed."
After its stint at the university, it was sold at scrap metal value to a group of students. It later ended up on a farm in Kent, whose owner donated it to the museum.
Of the 150 ICT 1301s built, only four are thought to survive, museum officials said, with the other three being beyond repair.
The goal is to repair the machine to running condition, they said.
"One of the problems with computers as museum artifacts is that when they are switched off they are fairly boring -- it's fairly difficult to learn anything from them," Murrell said.