What it was like to grow up around the world's first digital computers
And build slot machines out of the spare bits
Breaking a Dalek
Hartley reckons he owes his place in history and job on Titan to the personal intervention of Wilkes. The Cambridge lab chief had recognized that Hartley had talent, but he'd lacked the budget to hire him - Titan was the prototype of the Atlas 2 computer and was developed by Wilkes and Cambridge with the assistance of Ferranti, who’d supplied the chassis and peripherals. To get around the lack of funds, Wilkes diverted the money from one of the Titan’s tape drives and paid for Hartley instead.
Wilkes also took a keen personal interest in the careers of his colleagues and students - following their projects closely. If they were struggling he’d suggest that they should move on.
“It wasn’t quite sacking them ... he’d say you’d be better with so and so. He was right in every case. I know in the end that those people did well,” Hartley says. "Something he was unique for was his management of people’s careers.”
On the home front, Wilkes had a dad’s soft spot for his young son’s interests and development. Anthony recounts how his dad gave in and let him break up one particular old machine, something he describes as a “sizeable piece of apparatus” the shape of a Dalek and that once used to print output on paper tape, and which was locked in his dad’s shed.
“I believe he had intended to keep the machine back for a year two, until I was past my most destructive phases but I must have pestered persistently as before long it was handed over,” Anthony says. The parts were used to build an electromechanical slot machine.
The biggest prize for Anthony? A piece of computing history as dad gave him a panel containing the neon lights of the then de-commissioned EDSAC 2. The lights that had been the diagnostic display and the panel would have displayed the contents of EDSAC 2’s main registers. Anthony turned this into something to display different waveforms.
Today, the panel’s in TNMOC’s EDSAC 2 cabinet with the user and engineer's control panels. Wilkes involved his family, too, in his work.
Remembering dad and former boss: Anthony Wilkes (L) with
David Hartley, photo: TNMOC
Then there were the Saturday morning trips to the lab for Anthony and his sisters. Anthony recalls a place halfway between science and engineering shop, a place with scraps of aluminum littering the floor, a guillotine that would have flouted today's health and safety rules, metal air ducts carrying air cooled using liquid nitrogen from a plant in the courtyard, and the humming of machines.
Outside the lab, Wilkes traveled widely to help others start up computer groups, going as far afield as India when such travel was thought exotic.
“This was part of his genius,” Anthony says. “It was the first wave of computer popularization and his was anything but the life of a secluded boffin. He traveled widely helping groups to get going – I remember Bombay early on - evangelising we would call it now.”
Anthony recalls that his dad was an expert speechmaker with a dry and slightly subversive sense of humor, whose favorite joke involved the “binomial theorem and the common pump,” about some chap taking an examination.
Wilkes achieved a lot. His vision and drive saw three major computers delivered when there was no blueprint to follow, no footsteps to follow, and no manufacturing facilities to really build the systems.
His legacy to the world is the digital computer. His influence on his family has led to a son who runs his own software company involved in printed and handwritten music recognition and a daughter who'd visited who became a statistician.
Hartley tells us Wilkes was proud, rightly, of his achievements and saw EDSAC as his baby. He was jealous of his legacy, and wouldn't let others write it down. That he saved for his own memoirs.
Yet despite this pride and his vision and control, Wilkes remained a practical man. His era was one defined by big computers, systems that suited his style of command and control. It was a time when innovation was centralized around one machine and when somebody like Wilkes really could greenlight, push forward or kibosh a new idea or project.
By the 1980s, though, computing was getting decentralized with the arrival of the PC, and innovation was coming from all over. No one person could reasonably claim the monopoly over innovation any more.
Wilkes knew it was time to move on, so he retired from the Cambridge computing lab - the birthplace of EDSAC, EDSAC 2 and Titan.
“He knew the lab would have to change because the lab couldn’t flow from one man and the lab would have to broaden out. And it did,” Hartley says. ®