May 19, 2020
Today we’re going to cover the complicated legacy of Konrad Zuse.
Konrad Zuse is one of the biggest pioneers in early computing that relatively few have heard about. We tend to celebrate those who lived and worked in Allied countries in the World War II era. But Zuse had been born in Berlin in 1910. He worked in isolation during those early days, building his historic Z1 computer at 26 years old in his parents living room. It was 1936.
That computer was a mechanical computer and he was really more of a guru when it came to mechanical and electromechanical computing. Mechanical computing was a lot like watch-making, with gears, and automations. There was art in it, and Zuse had been an artist early on in life.
This was the first computer that really contained every part of what we would today think of a modern computer. It had a central processing control unit. It had memory. It had input through punched tape that could be used to program it. It even had floating point logic. It had an electric motor that ran at 1 hertz.
This design would live inside future computers that he built, but was destroyed in 1943 during air raids, and would be lost to history until Zuse built a replica in 1989.
He started building the Z2 in 1940. This used the same memory as the Z1 (64 words) but had 600 relays that allowed him to get up to 5 hertz. He’d also speed up calculations based on those relays, but the power required would jump up to a thousand watts. He would hand it over to the German DVL, now the German Aerospace Center. If there are Nazis on the moon, his computers likely put them there.
And this is really where the German authorities stepped in and, as with in the US, began funding efforts in technological advancement. They saw the value of modeling all the maths on these behemoths. They ponied up the cash to build the Z3. And this turned out to ironically be the first Turing-complete computer. He’d continue 22-bit word lengths and run at 5 hertz. But this device would have 2,600 relays and would help to solve wing flutter problems and other complicated aerodynamic mathematical mysteries. The machine also used Boolean algebra, a concept brought into computing independently by Claude Shannon in the US. It was finished in 1941, two years before Tommy Flowers finished the Colossus and 1 year before the Atanasoff-Berry Computer was built. And 7 years before ENIAC. And this baby was fast. Those relays crunched multiplication problems in 3 seconds. Suddenly you could calculate square roots in no time. But the German war effort was more focused on mechanical computing and this breakthrough was never considered critical to the war effort. Still, it was destroyed by allied air raids, just as its younger siblings had been.
The war had gone from 1939 to 1945, the year he married Gisela and his first child was born. He would finish building the Z4 days before the end of the war and met Alan Turing in 1947. He’d found Zuse KG in 1949. The Germans were emerging from a post-wartime depression and normalizing relations with the rest of Europe. The Z4 would finally go into production in Zurich in 1950. His team was now up to a couple dozen people and he was getting known. With electronics getting better and faster and better known, he was able to bring in specialists and with 2,500 relays - now 21 step-wise relays. - to get up to 40 hertz. And to under complicate something from a book I read, no Apple was not the first company to hook a keyboard up to a computer, the Zs did it in the 50s as they were now using a typewriter to help program the computer. OK, fine, ENIAC did it in 1946… But can you imagine hooking a keyboard up to a device rather than just tapping on the screen?!?! Archaic!
For two years, the Z4 was the only digital computer in all of Europe. But that was all about to change. They would refine the design and build the Z5, delivering it to Leitz GMBH in 1953. The Americans tried to recruit him to join their growing cache of computer scientists by sending Douglas Buck and others out. But he stayed on in Germany.
They would tinker with the designs and by 1955 came the Z11, shipping in 1957. This would be the first computer they produced multiple of in an almost assembly line building 48 and gave them enough money to build their next big success, the Z22. This was his seventh and would use vacuum tubes. And actually had an ALGOL 58 compiler. If you can believe it, the University of Applied Sciences, Karlsruhe still has one running! It added a rudimentary form of water cooling, teletype, drum memory, and core memory. They were now part of the computing mainstream.
And in 1961 they would go transistorized with the Z23. Ferrite memory. 150 kilohertz, Algol 60. This was on par with anything being built in the world. Transistors and diodes. They’d sell nearly 100 of them over the next few years. They would even have Z25 and Z26 variants. The Z31 would ship in 1963. They would make it to the Z43. But the company would run into financial problems and be sold to Siemens in 1967, who had gotten into computing in the 1950s. Being able to focus on something other than running a company prompted Zuse to write Calculating Space, effectively positing that the universe is a computational structure, now known as digital physics. He wasn’t weird, you’re weird. OK, he was…
e was never a Nazi, but he did build machines that could have helped their effort. You can trace the history of the mainframe era from gears to relays to tubes to transistors in his machines. IBM and other companies licensed his patents. And many advances were almost validated by him independently discovering them, like the use of Boolean algebra in computing. But to some degree he was a German in a lost era of history, often something that falls to the losers in a war.
So Konrad Zuse, thank you for one of the few clean timelines. It was a fun romp. I hope you have a lovely place in history, however complicated it may be. And thank you listeners, for tuning in to this episode of the history of computing podcast. We are so lucky to have you stop by. I hope you have a lovely and quite uncomplicated day!