3 ms·

Sure it is, but you have to define it better. He could build a difference engine much easier than he could build a system-on-chip. The difference engine would

Sure it is, but you have to define it better. He could build a difference engine much easier than he could build a system-on-chip. The difference engine would require metalworking and precision tools; the SoC would require a working digital computer to design, which requires lasers and other production technologies that in turn require advanced production technologies to make. Even if you just wanted to make a basic 4-bit machine with vacuum tubes, you'd still have to invent all of the preceding requisite technologies just to make the constituent components. A mechanical device would be much easier, and would be well within the capability of a single person with all of the prerequisite knowledge to make. Just look at the Antikythera Mechanism.

noonespecial 15y ago
This french HAM just about has it covered. He makes his tubes from nearly scratch. http://boingboing.net/2008/09/18/video-of-a-guy-who-m.html http://boingboing.net/2008/09/18/video-of-a-guy-who-m.html
- redthrowaway 15y ago
  That's hardly from scratch, though. Just look at all the different tools he uses. We didn't even have glasswork precise enough to use until the 18th century. Add arc welders, all of the chemicals (and chemistry, mining, etc) needed to make filaments, and everything else required and I doubt a person with full knowledge and access to all of the base materials, as they exist in nature, would be able to build a computer in their lifetime.
  - jquery 15y ago
    > full knowledge and access to all of the base materials, as they exist in nature, would be able to build a computer in their lifetime. Even that's a huge head start over having to mine the raw materials. It would probably take several lifetimes to build even the most basic computer from complete scratch even with all the manufacturing knowledge available.
sehugg 15y ago
For an electronic computer you also need a source of electricty -- and debugging is going to suck without a voltmeter, oscilloscope, logic analyzer or even LEDs. I'd go mechanical any day. I recall the Soviets had a computer based on liquid that could compute certain differential equations.
- chris11 15y ago
  There was a mechanical Turing machine shown at Makers Faire UK. Supposedly it was built only using hand tools and scrap parts. I'd say that's close enough to a hand-built computer. http://hackaday.com/2011/03/25/mechanical-turing-machine-can-compute-anything-slowly/ http://hackaday.com/2011/03/25/mechanical-turing-machine-can...

noonespecial 15y ago

This french HAM just about has it covered. He makes his tubes from nearly scratch. http://boingboing.net/2008/09/18/video-of-a-guy-who-m.html http://boingboing.net/2008/09/18/video-of-a-guy-who-m.html

redthrowaway 15y ago
That's hardly from scratch, though. Just look at all the different tools he uses. We didn't even have glasswork precise enough to use until the 18th century. Add arc welders, all of the chemicals (and chemistry, mining, etc) needed to make filaments, and everything else required and I doubt a person with full knowledge and access to all of the base materials, as they exist in nature, would be able to build a computer in their lifetime.
- jquery 15y ago
  > full knowledge and access to all of the base materials, as they exist in nature, would be able to build a computer in their lifetime. Even that's a huge head start over having to mine the raw materials. It would probably take several lifetimes to build even the most basic computer from complete scratch even with all the manufacturing knowledge available.

sehugg 15y ago

For an electronic computer you also need a source of electricty -- and debugging is going to suck without a voltmeter, oscilloscope, logic analyzer or even LEDs. I'd go mechanical any day. I recall the Soviets had a computer based on liquid that could compute certain differential equations.

chris11 15y ago
There was a mechanical Turing machine shown at Makers Faire UK. Supposedly it was built only using hand tools and scrap parts. I'd say that's close enough to a hand-built computer. http://hackaday.com/2011/03/25/mechanical-turing-machine-can-compute-anything-slowly/ http://hackaday.com/2011/03/25/mechanical-turing-machine-can...