Konrad Zuse's Homepage

When I was younger, I took debates over "who invented X" at face value, based on how engaged and serious others were about them: That person alone had the idea first, all by themselves, and realized it.

As an adult of course I realize the world is much more complicated. By and large, inventions don't happen in a vacuum, they occur when their time has come. Knowledge/ideas/theory/precursors are floating about, often there is a community of people already engaged in the area, and then at best someone makes a notable contribution or excels at integration, often boosted by fortuitous circumstances.

Yet these topics are rarely if ever reported on that way. At most you get a "someone else had written about it already in a paper" + debate about the chances the inventor had known and read about the paper (I think for Zuse this is the debate about whether he had read Turing or not).

For examples like this I'd love to read a more nuanced piece that takes me into the inventor's world first: What were the hot topics of their day? What devices were known to them already? Who were they in contact with? What inspired them? What allowed them to get organized and pursue a particular path? etc.

More often than not invention is a long process that involves multiple heads and years to decades.

I think I want a book like "The Making of the Atomic Bomb" by Rhodes, which really excels at sketching the milieu of first-half 20th century physics, but with Turing, von Neumann, Zuse, etc. instead ...

Can't you just marvel at the achievement without worrying whether celebrating this could be seen as taking something away from somebody else?

Personally I don't care much who was first. There were others roughly around the same time trying similar things. It's the same with "who invented the airplane" and "who invented radio". Many countries lay claim to having been the first to do X or Y. I don't care much and I don't think anybody else should.

Zuse built an amazing machine. Does that not warrant a bit of respect? Add that he had no help from the government or any big company. Does that still not warrant a bit of respect?

In my life I have "invented" quite a few algorithms that later turned out to be an old hat because smarter people had already invented them years or even decades earlier. To me that does not take away from my achievement :-)

It's not important whether you are the first one to achieve something. It is important that you achieved it.

I recall seeing: different physical blocks for different logic, a big regular blog for the memory and other blocks for ALU, etc, addressing handled by column and row selection lines, evaluating bit values by putting a signal onto the data line and seeing whether the value changes...

But all implemented with mechanical linkages (so a signal is a pull of a rod, a connection is a hooking of a rod onto some other linkage, etc.

A very simple Von Neumann style computer is the ByteByteJump. It has a single instruction (so no op code) with 3 address fields and it copies a single byte from the first address to the second address and then always jumps to the third address. If the addresses are 3 bytes long then every instruction takes up 9 bytes in memory. You can do math and logic operations by setting up 16KB tables in memory and then patching an instruction so the two operands are the bottom two bytes of the first address. To subtract the byte in address 0x001234 from the byte in address 0x00C0F0 and store the result in address 0x003333 on a little endian BBJ with a subtraction table at 0xD00000 you could use this sequence:

  0x100: 0x001234 0x000112 0x000109
  0x109: 0x00C0F0 0x000113 0x000112
  0x112: 0xD00000 0x003333 0x00011B
  0x11B:

Could the Z3 emulate this machine if given a 16MB memory it could interface to? Its instruction tape could be made into an infinite loop, which is good enough for this application. There are no other jumps or conditional execution in the emulator.

If you do need conditional execution to emulate a Turing complete machine (the Game Of Life, for example) then you might get by with conditional assignment instead. If the value of B is either 0 or 1, then Z:=A*B+C(1-B) will assign either A or C to Z. I am not familiar enough with the Z3 but would be surprised if it can't even do that.