Williams tube – cathode ray tube used as computer memory
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Williams tube – cathode ray tube used as computer memory
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Re: Williams tube – cathode ray tube used as computer memory
#2Pretty high data density for the time.
Re: Williams tube – cathode ray tube used as computer memory
#3This was part of The Baby, AKA the Manchester Small-Scale Experimental Machine at the University of Manchester in the late 40s. Modern replicas and simulators can be found at the university and Manchester's Museum of Science and Industry. It was built by Williams, Kilburn, and Tootill. Alan Turing wrote some programs for this machine.
One nicest things about this is that your memory is visible. You can just see which bits are on and which bits are off by looking at the screen. No debugger needed!
One of the least nice things was that these tubes had a reputation of being horribly unreliable.
Re: Williams tube – cathode ray tube used as computer memory
#4The variety of memory used for computers is amazing, and I find it a lot more interesting than the history of the CPU. CPU architecture is very diverse, but physically tends to be just different configurations of a few physical elements - relay, valve or transistor.
Memory had cathode ray tubes, mercury delay lines, dekatron and selectron tubes, core store, core rope, magnetic drums, tapes and discs, magnetostrictive delay lines, magneto-optical discs, and probably many more I don't know about, not counting the write-once formats like punched card and tape.
Re: Williams tube – cathode ray tube used as computer memory
#5The early days of electronic computing involved desperate attempts like this to build a fast temporary storage device. Things were in better shape on the arithmetic and control side - tubes worked, although it took some time to get component reliability up to an acceptable level. ENIAC, Colossus, and the IBM 603 Multiplier all had very limited memory, under 100 numbers.
This was a huge problem for anything that needed even a little storage. Western Union built Plan 55-A, a message switching system for telegrams, sort of like Sendmail. The buffering was all paper tape punches feeding paper tape readers. This was slow, expensive, and required large buildings full of paper tape gear and a huge staff. This was used from 1948 to 1976. The whole network of US paper tape gear switching centers was then replaced by one mainframe computer.
Today, we think nothing of software that needs a few gigabytes to display a text message.
Re: Williams tube – cathode ray tube used as computer memory
#6This was part of The Baby, AKA the Manchester Small-Scale Experimental Machine at the University of Manchester in the late 40s. Modern replicas and simulators can be found at the university and Manchester's Museum of Science and Industry. It was built by Williams, Kilburn, and Tootill. Alan Turing wrote some programs for this machine. One nicest things about this is that your memory is visible . You can just see whic…
Visible memory - useful indeed. As a newly minted mainframe engineer at IBM I worked with a guy who could read from punched paper tape by eye. It was most impressive watching him pulling it through his hands at a pretty good pace, reading it out as he went.
Re: Williams tube – cathode ray tube used as computer memory
#7There is an art installation that uses cathode ray tubes: http://www.alpha60.de/art/love_letters/
I guess that they probably don't use the tubes as the actual memory. But it looks extremely cool.
Re: Williams tube – cathode ray tube used as computer memory
#8The early days of electronic computing involved desperate attempts like this to build a fast temporary storage device. Things were in better shape on the arithmetic and control side - tubes worked, although it took some time to get component reliability up to an acceptable level. ENIAC, Colossus, and the IBM 603 Multiplier all had very limited memory, under 100 numbers. This was a huge problem for anything that neede…
Business computing had always used more memory. IBM had very interesting devices with punch cards.
It's interesting to compare these two big strands: business vs scientific computing.
Re: Williams tube – cathode ray tube used as computer memory
#9The variety of memory used for computers is amazing, and I find it a lot more interesting than the history of the CPU. CPU architecture is very diverse, but physically tends to be just different configurations of a few physical elements - relay, valve or transistor. Memory had cathode ray tubes, mercury delay lines, dekatron and selectron tubes, core store, core rope, magnetic drums, tapes and discs, magnetostrictive…
One of my favorite backwaters of technology is the work they did in the 50's and 60's with "cryotrons", which were essentially like superconducting transistors that switched by one superconductor temporarily destroying another's superconductivity. They apparently even made a working memory module out of them and provided it to the NSA before the transistor came along and changed everything.
Re: Williams tube – cathode ray tube used as computer memory
#10This was part of The Baby, AKA the Manchester Small-Scale Experimental Machine at the University of Manchester in the late 40s. Modern replicas and simulators can be found at the university and Manchester's Museum of Science and Industry. It was built by Williams, Kilburn, and Tootill. Alan Turing wrote some programs for this machine. One nicest things about this is that your memory is visible . You can just see whic…
Visible memory - useful indeed. As a newly minted mainframe engineer at IBM I worked with a guy who could read from punched paper tape by eye. It was most impressive watching him pulling it through his hands at a pretty good pace, reading it out as he went.
I worked with Tim Paterson (creator of MS-DOS) when I worked on the Visual Basic team at Microsoft. When he worked on code generation he just read hex dumps, not disassembly, because it was faster for him.