Just one of 21 cabinets making up the computer.
The first computer so cheap that they gave it away on the cover of a
magazine
What do you think the relationship is between the speeds of the two computers?
What do you think the relationship is between the speeds of the two computers?
The Raspberry Pi is about one million times faster...
What do you think the relationship is between the speeds of the two computers?
The Raspberry Pi is about one million times faster...
Which means: If they had run the Elliot 24 hours a day for 10 years, it would have done the amount of computing you can do on a Raspberry Pi Zero in about 5 minutes!
So the Raspberry Pi is:
A factor of a million million.
A terabyte is a million million bytes: nowadays we talk in terms of very large numbers.
Want to guess how long a million million seconds is?
So the Raspberry Pi is:
A factor of a million million.
A terabyte is a million million bytes: nowadays we talk in terms of very large numbers.
Want to guess how long a million million seconds is?
It's 30,000 years... In other words, a really big number...
In fact a million million times improvement is about what you would expect from Moore's Law over 58 years.
Except: the Raspberry Pi is two million times smaller as well, so it is much better than even that.
In 2015 Moore's Law turned 50 years old.
Or less prosaically: Moore's Law was 33⅓ iterations of itself old.
The first time I head that Moore's Law was nearly at an end was in 1977. From no less than Grace Hopper, at Manchester University.
Since then I have heard many times that it was close to its end, or even has already ended. There was a burst of such claims in 2015, which caused a wag to tweet:
"The number of press articles speculating the end of Moore's Law doubles every eighteen months."
Often people don't understand the true effects of exponential growth.
A BBC reporter: "Your current PC is more powerful than the computer they had on board the first flight to the moon". True, but oh so wrong.
Take a piece of paper, divide it in two, and write this year's date in one half:
Divide the other half in two vertically; write the date 18 months ago in half:
Divide the remains in half, and write the date 18 months earlier:
Repeat until your pen is thicker than the space you have to divide in two:
This demonstrates that your current computer is more powerful than all other computers you have ever had put together (and way more powerful than the computer they had on board the first moonshot).
In the 50's, computers cost in the millions. Nearly no one bought them, nearly everyone leased them.
To rent time on a computer then would cost you of the order of $1000 per hour: several times the annual salary of a programmer!
When you leased a computer in those days, you would get programmers for free to go with it.
Compared to the cost of a computer, a programmer was almost free.
In the 50's the computer's time was expensive. A
programmer would:
Why? Because it was much cheaper to let 3 people check it, than to let the computer discover the errors.
And so programming languages were designed around the needs of the computer, not the programmer.
It was much cheaper to let the programmer spend lots of time producing a program than to let the computer do some of the work for you.
Programming languages were designed so that you tell the computer exactly what to do, in its terms, not what you want to achieve in yours.
A short ten years later, there was already talk of a software crisis.
Programs being written that weren't functional, and/or weren't delivered on time.
It happened slowly, almost unnoticed, but nowadays we have the exact opposite position:
Compared to the cost of a programmer, a computer is almost free.
I call this Moore's Switch.
Relative costs of computers and programmers, 1957-2017
But, we are still programming in programming languages that are direct descendants of the languages designed in the 1950's!
We are still telling the computers what to do.
A new way of programming: declarative programming.
This describes what you want to achieve, but not how to achieve it.
Let me give some examples.
Declarative approaches describe the solution space.
A classic example is when you learn in school that
The square root of a number n is the number r such that r × r = n
This doesn't tell you how to calculate the square root; but no problem, because we have machines to do that for us.
function f a: {
x ← a
x' ← (a + 1) ÷ 2
epsilon ← 1.19209290e-07
while abs(x − x') > epsilon × x: {
x ← x'
x' ← ((a ÷ x') + x') ÷ 2
}
return x'
}
1000 lines, almost all of it administrative. Only 2 or 3 lines have anything to do with telling the time.
And this was the smallest example I could find. The largest was more than 4000 lines.
type clock = (h, m, s) displayed as circled(combined(hhand; mhand; shand; decor)) shand = line(slength) rotated (s × 6) mhand = line(mlength) rotated (m × 6) hhand = line(hlength) rotated (h × 30 + m ÷ 2) decor = ... slength = ... ... clock c c.s = system:seconds mod 60 c.m = (system:seconds div 60) mod 60 c.h = (system:seconds div 3600) mod 24
XForms is a declarative system that lets you define applications. 
It is a W3C standard, and in worldwide use.
A certain company makes one-off BIG machines (walk in): user interface is very demanding — traditionally needed 5 years, 30 people.
With XForms this became: 1 year, 10 people.
Do the sums. Assume one person costs 100k a year. Then this has gone from a 15M cost to a 1M cost. They have saved 14 million! (And 4 years)
Manager: I want you to come back to me in 2 days with estimates of how long it will take your teams to make the application.
Manager: I want you to come back to me in 2 days with estimates of how long it will take your teams to make the application.
[Two days later]
Programmer: I'll need 30 days to work out how long it will take to program it.
Manager: I want you to come back to me in 2 days with estimates of how long it will take your teams to make the application.
[Two days later]
Programmer: I'll need 30 days to work out how long it will take to program it.
XFormser: I've already programmed it!
The British National Health Service started a project for a health records system.
The British National Health Service started a project for a health records system.
One person then created a system using XForms.
For historical reasons, present programming languages are at the wrong level of abstraction: they don't describe the problem, but only one particular solution to the problem.
Once project managers realise they can save 90% on programming costs, they will switch to declarative programming.
I believe that eventually everyone will be programming declaratively: less errors, more time, more productivity.
Declarative programming allows programmers to be ten times more productive: what you now write in a week, would take a morning; what now takes a month would take a couple of days.