Embedded Systems Conference
Breaking News
Engineering Pop Culture!

Leonard Nimoy, We'll Miss you

View Comments: Oldest First | Newest First | Threaded View
User Rank
Memory interface with tubes
traneus   3/2/2015 9:47:54 AM
"In fact, how could Spock even build a memory interface with tubes? They can't possibly switch fast enough? But, that's the beauty of science fiction."

If you're coming to ESC Boston, you can go to the MIT Museum, and see a memory interface built in 1952 or 1953 with tubes.

The first magnetic-core memory system, part of the Whirlwind computer, used what look to my eyes to be 6AS7 dual power triodes as row and column drivers. According to Wikipedia (magnetic-core-memory), the memory was 1024 words of two bytes each, with an access time of  9 microseconds. Such a 2 Kbyte RAM would be a good match for an 8008 microprocessor, though a little slow.

I agree that it was difficult to build computer terminals using tubes. That's why computer terminals used to be purely mechanical beasts. Look up Teletype and Flexowriter for details.

When the original Star Trek series was broadcast, tube-based television sets and radios, while old-fashioned, were still in production.

One of the first personal computers advertised as such, was the LGP-30 of 1965: no transistors, no integrated circuits, 100 tubes, lots of germanium diodes, Flexowriter user interface, the size of a desk, plugged into ordinary office power outlet.

User Rank
Re: Memory interface with tubes
Les_Slater   3/2/2015 11:24:09 AM
Not only memory interface, but memory itself was built with tubes. Back in the late 40's there was something called the Williams tube that was a CRT which when writing to XY positions on the phosphor surface a charge well was created at that location which could be read by erasing it and detecting a current coupled to a metal plate on the surfaace. 

Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week