* Posts by Andrew Alcock

7 publicly visible posts • joined 27 Jun 2007

All-optical RAM to clear comms bottleneck

Andrew Alcock

Re: Oh dear, oh dear - you don't remember your history do you

D'oh - should have said 1948, not 1946.

Andrew Alcock

Re: Re: Re: Oh dear, oh dear - you don't remember your history do you


Given the right conditions, painting memory can last 30,000 years, a rather better MTBF than magnetic media.

Andrew Alcock

Re: Re: Oh dear, oh dear - you don't remember your history do you

Well, then, neither was the Mellon optical memory linked to by the author:

"To form a complete memory the system was arranged to be regenerative, with the output of the photocells being amplified and sent back into the CRT to refresh the cells periodically."

The difference is simply that the decay on the Mellon system was longer than the decay on the Williams CRT, so the refresh rate was lower.

My favorite highly impractical early computer memory was http://en.wikipedia.org/wiki/Delay_line_memory#Mercury_delay_lines

Andrew Alcock

Oh dear, oh dear - you don't remember your history do you

The world's second computer - the Manchester Mark 1 (disclosure, I went to Cambridge, and so would argue vociferously that Cambridge beat Manchester in the race) - had the "William's tube" CRT memory in 1946:


And here is another photograph of CRT memory:


North Korea photoshops stroke from Kim Jong Il

Andrew Alcock
Black Helicopters

There seem to be different "official" images...

A Korean source has a subtly different version of the same image:


The shadow is slanted in this picture, but is obviously a straight line rather than the more complex ones of the soldiers standing next to him. The line on the white step is missing in this picture as well.

Shurely both can't be right?

Airbus delivers first A380

Andrew Alcock

Mile high club

The SQ 380 has first class suites - with doors - containing a private double bed. If you flash the cash for first, you don't have to attempt vigorous interpersonal integration in a the vertical orientation in a tiny smelly cubicle. I'm saving my air miles for a truly memorable flight of fantasy.

Sun's new supercomputer and switch are bigger than yours

Andrew Alcock

Here's the pictures...

... and boy is it a big switch