3 ms·

> I think the main innovation was the use of valves (similar to tube logic), while other machines of the day used relay logic. Vacuum tubes and Thermionic Valv

> I think the main innovation was the use of valves (similar to tube logic), while other machines of the day used relay logic. Vacuum tubes and Thermionic Valves are the same thing. "Tubes" is the name that stuck in the states. "Valves" in the UK. > This thing wasn’t really a computer though, in that it was not turing complete, Turing completeness isn't a requisit to compute. Tommy Flower's big step was taking the electronic switching technology used in telephone exchanges and applying it the computation. Others said that they would be unreliable with the switching speeds involved and mechanical switches were the only way to do it. Flower's knew the key to reliability was thermal stability and designed his machine. > > These first turing complete machine that “worked” was probably the Z3 from 1941. No, it didn't have a condition branch. Z4 had that, but after ENIAC did. https://en.m.wikipedia.org/wiki/Turing_completeness https://en.m.wikipedia.org/wiki/Turing_completeness

adrian_b 2y ago
The Atanasoff–Berry computer was even earlier (working prototype in 1942, but much of the design had already been done by 1940). This was not a general-purpose computer, but a computer made with vacuum tubes that was dedicated to solving a single kind of problem, the solution of systems of linear equations. The Atanasoff–Berry computer not only used vacuum tubes for computation, but it also included the first DRAM memory, which was made with discrete capacitors. The report “Computing Machine for the Solution of Large Systems of Linear Algebraic Equations”, written by John V. Atanasoff in 1940, demonstrates a very good understanding for that time of the principles on which electronic computing circuits and memories should be based. Moreover, the electronic circuits used in the Atanasoff–Berry computer have been a source of inspiration for the later ENIAC, because one of the members of the ENIAC team has made a visit there, inquiring about details of the computer. While the Atanasoff–Berry computer is likely to have been the first which has used vacuum tubes for computation, it has been derived from a series of British inventions made during the previous decade, which were used for making electronic counters used in nuclear and particle physics research, for measuring ionizing radiation. The electronic counters had been the first application of digital circuits made with vacuum or gas tubes, before automatic computers. The well-known high speed of the electronic counters is what has suggested the application of vacuum tubes for computing, both in USA with ABC, then ENIAC, and in UK, with Colossus.
hedora 2y ago
Apparently, someone proved the Z3 was Turing complete about ten years ago. The Wikipedia article I linked claims this. I wonder if it was “accidentally” Turing complete, or if it was turing complete when used as intended. It’s silent on the z1 and z2’s turing completeness, but I don’t think those ever actually worked, sort of making it a moot point. (Agreed about “computer” being a fuzzy definition - Surely the mercury pool tabulators the US census used could compute stuff, they predated tubes, and maybe even relays.)

adrian_b 2y ago

The Atanasoff–Berry computer was even earlier (working prototype in 1942, but much of the design had already been done by 1940). This was not a general-purpose computer, but a computer made with vacuum tubes that was dedicated to solving a single kind of problem, the solution of systems of linear equations. The Atanasoff–Berry computer not only used vacuum tubes for computation, but it also included the first DRAM memory, which was made with discrete capacitors. The report “Computing Machine for the Solution of Large Systems of Linear Algebraic Equations”, written by John V. Atanasoff in 1940, demonstrates a very good understanding for that time of the principles on which electronic computing circuits and memories should be based. Moreover, the electronic circuits used in the Atanasoff–Berry computer have been a source of inspiration for the later ENIAC, because one of the members of the ENIAC team has made a visit there, inquiring about details of the computer. While the Atanasoff–Berry computer is likely to have been the first which has used vacuum tubes for computation, it has been derived from a series of British inventions made during the previous decade, which were used for making electronic counters used in nuclear and particle physics research, for measuring ionizing radiation. The electronic counters had been the first application of digital circuits made with vacuum or gas tubes, before automatic computers. The well-known high speed of the electronic counters is what has suggested the application of vacuum tubes for computing, both in USA with ABC, then ENIAC, and in UK, with Colossus.

hedora 2y ago

Apparently, someone proved the Z3 was Turing complete about ten years ago. The Wikipedia article I linked claims this. I wonder if it was “accidentally” Turing complete, or if it was turing complete when used as intended. It’s silent on the z1 and z2’s turing completeness, but I don’t think those ever actually worked, sort of making it a moot point. (Agreed about “computer” being a fuzzy definition - Surely the mercury pool tabulators the US census used could compute stuff, they predated tubes, and maybe even relays.)