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The history of computing is usually described as a nice progression from vacuum tubes to transistors and then ICs. But parametrons are only one of the many forg

by kens 2mo ago

The history of computing is usually described as a nice progression from vacuum tubes to transistors and then ICs. But parametrons are only one of the many forgotten technologies that popped up along the way. Magnetic core logic such as transfluxors was used in several computers. Superconducting cryotrons were going to revolutionize computers. Tunnel-diode logic was also briefly the wave of the future. Other significant technologies were microwave logic circuits and electroluminescent logic circuits. I have to say that the 1950s came up with the best names; modern technologies just don't measure up to transfluxors, parametrons, and cryotrons. See Digital Computer Design Fundamentals, 1962, chapter 6.

Animats 2mo ago
Right. So many things were tried in the 1950s. There was a lot of interest in nonlinear magnetic devices. UNIVAC had magnetic amplifiers in their "Solid State" computer (1958). Magnetic devices have the nice property that there's no wear-out mechanism. They're just coils and magnetic materials. They just keep going, for many decades. The Bell System loved nonlinear magnetic devices. There were lots of them, usually potted inside little grey boxes. Here's one of many on eBay.[1] [1] https://www.ebay.com/itm/318704409860 https://www.ebay.com/itm/318704409860
- ahartmetz 2mo ago
  Reportedly (English Wikipedia + other sources I forgot), the popularity of magnetic amplifiers in the US after WW2 had something to do with reverse engineering German weapon systems where such amplifiers were widely used and had received a corresponding amount of engineering work. They were great at the time unless you needed high bandwidth or light weight.
kazinator 2mo ago
Don't forget good old relays.
ajb 2mo ago
My high school computing teacher had a chemistry degree, from back around then. There was so much expectation about computers, that when the chemicals he was doing his phd on seemed to have some kind of nonlinear behaviour, his supervisor got hugely excited and made him look into whether there was a way use them to build switching devices; even though it would have been highly impractical even if they had. Basically everyone was trying ways to make switches.

by kens 2mo ago

Animats 2mo ago

Right. So many things were tried in the 1950s. There was a lot of interest in nonlinear magnetic devices. UNIVAC had magnetic amplifiers in their "Solid State" computer (1958). Magnetic devices have the nice property that there's no wear-out mechanism. They're just coils and magnetic materials. They just keep going, for many decades. The Bell System loved nonlinear magnetic devices. There were lots of them, usually potted inside little grey boxes. Here's one of many on eBay.[1] [1] https://www.ebay.com/itm/318704409860 https://www.ebay.com/itm/318704409860

ahartmetz 2mo ago
Reportedly (English Wikipedia + other sources I forgot), the popularity of magnetic amplifiers in the US after WW2 had something to do with reverse engineering German weapon systems where such amplifiers were widely used and had received a corresponding amount of engineering work. They were great at the time unless you needed high bandwidth or light weight.

kazinator 2mo ago

Don't forget good old relays.

ajb 2mo ago

My high school computing teacher had a chemistry degree, from back around then. There was so much expectation about computers, that when the chemicals he was doing his phd on seemed to have some kind of nonlinear behaviour, his supervisor got hugely excited and made him look into whether there was a way use them to build switching devices; even though it would have been highly impractical even if they had. Basically everyone was trying ways to make switches.