0:00:00.106,0:00:01.530
So the machine I'm going to talk you about

0:00:01.530,0:00:03.204
is what I call the greatest machine that never was.

0:00:03.204,0:00:05.203
It was a machine that was never built,

0:00:05.203,0:00:07.583
and yet, it will be built.

0:00:07.583,0:00:09.575
It was a machine that was designed

0:00:09.575,0:00:11.926
long before anyone thought about computers.

0:00:11.926,0:00:14.075
If you know anything about the history of computers,

0:00:14.075,0:00:16.595
you will know that in the '30s and the '40s,

0:00:16.595,0:00:19.150
simple computers were created

0:00:19.150,0:00:21.943
that started the computer revolution we have today,

0:00:21.943,0:00:23.229
and you would be correct,

0:00:23.229,0:00:25.711
except for you'd have the wrong century.

0:00:25.711,0:00:27.351
The first computer was really designed

0:00:27.351,0:00:31.023
in the 1830s and 1840s, not the 1930s and 1940s.

0:00:31.023,0:00:33.351
It was designed, and parts of it were prototyped,

0:00:33.351,0:00:35.487
and the bits of it that were built are here

0:00:35.487,0:00:37.480
in South Kensington.

0:00:37.480,0:00:40.799
That machine was built by this guy, Charles Babbage.

0:00:40.799,0:00:42.555
Now, I have a great affinity for Charles Babbage

0:00:42.555,0:00:45.164
because his hair is always completely unkempt like this

0:00:45.164,0:00:47.505
in every single picture. (Laughter)

0:00:47.505,0:00:49.352
He was a very wealthy man, and a sort of,

0:00:49.352,0:00:51.365
part of the aristocracy of Britain,

0:00:51.365,0:00:53.704
and on a Saturday night in Marylebone,

0:00:53.704,0:00:56.135
were you part of the intelligentsia of that period,

0:00:56.135,0:00:57.631
you would have been invited round to his house

0:00:57.631,0:01:00.590
for a soiree — and he invited everybody:

0:01:00.590,0:01:04.022
kings, the Duke of Wellington, many, many famous people —

0:01:04.022,0:01:06.543
and he would have shown you one of his mechanical machines.

0:01:06.543,0:01:09.583
I really miss that era, you know, where you could

0:01:09.583,0:01:11.931
go around for a soiree and see a mechanical computer

0:01:11.931,0:01:13.044
get demonstrated to you. (Laughter)

0:01:13.044,0:01:16.310
But Babbage, Babbage himself was born

0:01:16.310,0:01:18.044
at the end of the 18th century,

0:01:18.044,0:01:20.088
and was a fairly famous mathematician.

0:01:20.088,0:01:23.231
He held the post that Newton held at Cambridge,

0:01:23.231,0:01:25.743
and that was recently held by Stephen Hawking.

0:01:25.743,0:01:28.598
He's less well known than either of them because

0:01:28.598,0:01:31.748
he got this idea to make mechanical computing devices

0:01:31.748,0:01:34.033
and never made any of them.

0:01:34.033,0:01:37.318
The reason he never made any of them, he's a classic nerd.

0:01:37.318,0:01:39.329
Every time he had a good idea, he'd think,

0:01:39.329,0:01:40.777
"That's brilliant, I'm going to start building that one.

0:01:40.777,0:01:43.372
I'll spend a fortune on it. I've got a better idea.

0:01:43.372,0:01:45.732
I'm going to work on this one. (Laughter) And I'm going to do this one."

0:01:45.732,0:01:48.612
He did this until Sir Robert Peel, then Prime Minister,

0:01:48.612,0:01:51.076
basically kicked him out of Number 10 Downing Street,

0:01:51.076,0:01:53.517
and kicking him out, in those days, that meant saying,

0:01:53.517,0:01:56.669
"I bid you good day, sir." (Laughter)

0:01:56.669,0:01:58.649
The thing he designed was this monstrosity here,

0:01:58.649,0:02:02.088
the analytical engine. Now, just to give you an idea of this,

0:02:02.088,0:02:03.960
this is a view from above.

0:02:03.960,0:02:07.073
Every one of these circles is a cog, a stack of cogs,

0:02:07.073,0:02:10.309
and this thing is as big as a steam locomotive.

0:02:10.309,0:02:12.300
So as I go through this talk, I want you to imagine

0:02:12.300,0:02:14.944
this gigantic machine. We heard those wonderful sounds

0:02:14.944,0:02:16.704
of what this thing would have sounded like.

0:02:16.704,0:02:18.481
And I'm going to take you through the architecture of the machine

0:02:18.481,0:02:19.960
— that's why it's computer architecture —

0:02:19.960,0:02:23.287
and tell you about this machine, which is a computer.

0:02:23.287,0:02:26.690
So let's talk about the memory. The memory

0:02:26.690,0:02:28.937
is very like the memory of a computer today,

0:02:28.937,0:02:31.639
except it was all made out of metal,

0:02:31.639,0:02:35.183
stacks and stacks of cogs, 30 cogs high.

0:02:35.183,0:02:37.253
Imagine a thing this high of cogs,

0:02:37.253,0:02:39.008
hundreds and hundreds of them,

0:02:39.008,0:02:40.898
and they've got numbers on them.

0:02:40.898,0:02:43.317
It's a decimal machine. Everything's done in decimal.

0:02:43.317,0:02:44.902
And he thought about using binary. The problem

0:02:44.902,0:02:46.620
with using binary is that the machine would have been so

0:02:46.620,0:02:49.937
tall, it would have been ridiculous. As it is, it's enormous.

0:02:49.937,0:02:51.996
So he's got memory.

0:02:51.996,0:02:54.403
The memory is this bit over here.

0:02:54.403,0:02:56.733
You see it all like this.

0:02:56.733,0:03:01.268
This monstrosity over here is the CPU, the chip, if you like.

0:03:01.268,0:03:03.518
Of course, it's this big.

0:03:03.518,0:03:06.431
Completely mechanical. This whole machine is mechanical.

0:03:06.431,0:03:10.572
This is a picture of a prototype for part of the CPU

0:03:10.572,0:03:12.711
which is in the Science Museum.

0:03:12.711,0:03:16.343
The CPU could do the four fundamental functions of arithmetic --

0:03:16.343,0:03:18.796
so addition, multiplication, subtraction, division --

0:03:18.796,0:03:21.804
which already is a bit of a feat in metal,

0:03:21.804,0:03:24.433
but it could also do something that a computer does

0:03:24.433,0:03:26.132
and a calculator doesn't:

0:03:26.132,0:03:30.070
this machine could look at its own internal memory and make a decision.

0:03:30.070,0:03:32.936
It could do the "if then" for basic programmers,

0:03:32.936,0:03:35.076
and that fundamentally made it into a computer.

0:03:35.076,0:03:39.674
It could compute. It couldn't just calculate. It could do more.

0:03:39.674,0:03:42.355
Now, if we look at this, and we stop for a minute,

0:03:42.355,0:03:44.226
and we think about chips today, we can't

0:03:44.226,0:03:48.041
look inside a silicon chip. It's just so tiny.

0:03:48.041,0:03:49.842
Yet if you did, you would see something

0:03:49.842,0:03:51.664
very, very similar to this.

0:03:51.664,0:03:54.611
There's this incredible complexity in the CPU,

0:03:54.611,0:03:57.303
and this incredible regularity in the memory.

0:03:57.303,0:03:58.965
If you've ever seen an electron microscope picture,

0:03:58.965,0:04:00.934
you'll see this. This all looks the same,

0:04:00.934,0:04:03.500
then there's this bit over here which is incredibly complicated.

0:04:03.500,0:04:07.483
All this cog wheel mechanism here is doing is what a computer does,

0:04:07.483,0:04:09.576
but of course you need to program this thing, and of course,

0:04:09.576,0:04:12.601
Babbage used the technology of the day

0:04:12.601,0:04:16.247
and the technology that would reappear in the '50s, '60s and '70s,

0:04:16.247,0:04:19.116
which is punch cards. This thing over here

0:04:19.116,0:04:21.940
is one of three punch card readers in here,

0:04:21.940,0:04:25.620
and this is a program in the Science Museum, just

0:04:25.620,0:04:30.013
not far from here, created by Charles Babbage,

0:04:30.013,0:04:31.881
that is sitting there — you can go see it —

0:04:31.881,0:04:34.322
waiting for the machine to be built.

0:04:34.322,0:04:37.742
And there's not just one of these, there's many of them.

0:04:37.742,0:04:40.832
He prepared programs anticipating this would happen.

0:04:40.832,0:04:42.805
Now, the reason they used punch cards was that Jacquard,

0:04:42.805,0:04:44.977
in France, had created the Jacquard loom,

0:04:44.977,0:04:47.655
which was weaving these incredible patterns controlled by punch cards,

0:04:47.655,0:04:50.287
so he was just repurposing the technology of the day,

0:04:50.287,0:04:52.392
and like everything else he did, he's using the technology

0:04:52.392,0:04:57.139
of his era, so 1830s, 1840s, 1850s, cogs, steam,

0:04:57.139,0:05:01.077
mechanical devices. Ironically, born the same year

0:05:01.077,0:05:03.249
as Charles Babbage was Michael Faraday,

0:05:03.249,0:05:05.926
who would completely revolutionize everything

0:05:05.926,0:05:08.439
with the dynamo, transformers, all these sorts of things.

0:05:08.439,0:05:11.597
Babbage, of course, wanted to use proven technology,

0:05:11.597,0:05:13.150
so steam and things.

0:05:13.150,0:05:14.823
Now, he needed accessories.

0:05:14.823,0:05:16.495
Obviously, you've got a computer now.

0:05:16.495,0:05:18.884
You've got punch cards, a CPU and memory.

0:05:18.884,0:05:20.819
You need accessories you're going to come with.

0:05:20.819,0:05:22.447
You're not just going to have that,

0:05:22.447,0:05:25.275
So, first of all, you had sound. You had a bell,

0:05:25.275,0:05:27.429
so if anything went wrong — (Laughter) —

0:05:27.429,0:05:29.774
or the machine needed the attendant to come to it,

0:05:29.774,0:05:31.744
there was a bell it could ring. (Laughter)

0:05:31.744,0:05:33.280
And there's actually an instruction on the punch card

0:05:33.280,0:05:36.182
which says "Ring the bell." So you can imagine this "Ting!"

0:05:36.182,0:05:38.382
You know, just stop for a moment, imagine all those noises,

0:05:38.382,0:05:39.463
this thing, "Click, clack click click click,"

0:05:39.463,0:05:42.400
steam engine, "Ding," right? (Laughter)

0:05:42.400,0:05:44.835
You also need a printer, obviously, and everyone needs a printer.

0:05:44.835,0:05:47.843
This is actually a picture of the printing mechanism for

0:05:47.843,0:05:50.326
another machine of his, called the Difference Engine No. 2,

0:05:50.326,0:05:52.261
which he never built, but which the Science Museum

0:05:52.261,0:05:54.432
did build in the '80s and '90s.

0:05:54.432,0:05:56.707
It's completely mechanical, again, a printer.

0:05:56.707,0:05:59.405
It prints just numbers, because he was obsessed with numbers,

0:05:59.405,0:06:02.922
but it does print onto paper, and it even does word wrapping,

0:06:02.922,0:06:05.694
so if you get to the end of the line, it goes around like that.

0:06:05.694,0:06:07.344
You also need graphics, right?

0:06:07.344,0:06:08.900
I mean, if you're going to do anything with graphics,

0:06:08.900,0:06:11.496
so he said, "Well, I need a plotter. I've got a big piece of paper

0:06:11.496,0:06:13.604
and an ink pen and I'll make it plot."

0:06:13.604,0:06:15.434
So he designed a plotter as well,

0:06:15.434,0:06:19.359
and, you know, at that point, I think he got pretty much

0:06:19.359,0:06:20.890
a pretty good machine.

0:06:20.890,0:06:23.580
Along comes this woman, Ada Lovelace.

0:06:23.580,0:06:26.301
Now, imagine these soirees, all these great and good comes along.

0:06:26.301,0:06:29.393
This lady is the daughter of the mad, bad

0:06:29.393,0:06:31.815
and dangerous-to-know Lord Byron,

0:06:31.815,0:06:34.335
and her mother, being a bit worried that she might have

0:06:34.335,0:06:37.192
inherited some of Lord Byron's madness and badness,

0:06:37.192,0:06:40.430
thought, "I know the solution: Mathematics is the solution.

0:06:40.430,0:06:43.379
We'll teach her mathematics. That'll calm her down."

0:06:43.379,0:06:47.135
(Laughter) Because of course,

0:06:47.135,0:06:51.050
there's never been a mathematician that's gone crazy,

0:06:51.050,0:06:53.451
so, you know, that'll be fine. (Laughter)

0:06:53.451,0:06:56.789
Everything'll be fine. So she's got this mathematical training,

0:06:56.789,0:06:59.527
and she goes to one of these soirees with her mother,

0:06:59.527,0:07:02.317
and Charles Babbage, you know, gets out his machine.

0:07:02.317,0:07:04.151
The Duke of Wellington is there, you know,

0:07:04.151,0:07:05.723
get out the machine, obviously demonstrates it,

0:07:05.723,0:07:09.474
and she gets it. She's the only person in his lifetime, really,

0:07:09.474,0:07:10.766
who said, "I understand what this does,

0:07:10.766,0:07:12.973
and I understand the future of this machine."

0:07:12.973,0:07:16.060
And we owe to her an enormous amount because we know

0:07:16.060,0:07:19.037
a lot about the machine that Babbage was intending to build

0:07:19.037,0:07:20.640
because of her.

0:07:20.640,0:07:23.397
Now, some people call her the first programmer.

0:07:23.397,0:07:26.783
This is actually from one of -- the paper that she translated.

0:07:26.783,0:07:29.694
This is a program written in a particular style.

0:07:29.694,0:07:33.263
It's not, historically, totally accurate that she's the first programmer,

0:07:33.263,0:07:35.316
and actually, she did something more amazing.

0:07:35.316,0:07:36.886
Rather than just being a programmer,

0:07:36.886,0:07:39.058
she saw something that Babbage didn't.

0:07:39.058,0:07:42.242
Babbage was totally obsessed with mathematics.

0:07:42.242,0:07:46.191
He was building a machine to do mathematics,

0:07:46.191,0:07:49.450
and Lovelace said, "You could do more than mathematics

0:07:49.450,0:07:52.285
on this machine." And just as you do,

0:07:52.285,0:07:53.910
everyone in this room already's got a computer on them

0:07:53.910,0:07:55.964
right now, because they've got a phone.

0:07:55.964,0:07:58.192
If you go into that phone, every single thing in that phone

0:07:58.192,0:08:00.207
or computer or any other computing device

0:08:00.207,0:08:02.288
is mathematics. It's all numbers at the bottom.

0:08:02.288,0:08:06.981
Whether it's video or text or music or voice, it's all numbers,

0:08:06.981,0:08:10.961
it's all, underlying it, mathematical functions happening,

0:08:10.961,0:08:13.066
and Lovelace said, "Just because you're doing

0:08:13.066,0:08:16.388
mathematical functions and symbols

0:08:16.388,0:08:18.635
doesn't mean these things can't represent

0:08:18.635,0:08:21.988
other things in the real world, such as music."

0:08:21.988,0:08:24.722
This was a huge leap, because Babbage is there saying,

0:08:24.722,0:08:26.944
"We could compute these amazing functions and print out

0:08:26.944,0:08:30.612
tables of numbers and draw graphs," — (Laughter) —

0:08:30.612,0:08:32.508
and Lovelace is there and she says, "Look,

0:08:32.508,0:08:34.984
this thing could even compose music if you

0:08:34.984,0:08:38.532
told it a representation of music numerically."

0:08:38.532,0:08:40.101
So this is what I call Lovelace's Leap.

0:08:40.101,0:08:43.838
When you say she's a programmer, she did do some,

0:08:43.838,0:08:46.975
but the real thing is to have said the future is going to be

0:08:46.975,0:08:49.171
much, much more than this.

0:08:49.171,0:08:51.350
Now, a hundred years later, this guy comes along,

0:08:51.350,0:08:56.803
Alan Turing, and in 1936, and invents the computer all over again.

0:08:56.803,0:08:59.380
Now, of course, Babbage's machine was entirely mechanical.

0:08:59.380,0:09:01.911
Turing's machine was entirely theoretical.

0:09:01.911,0:09:04.702
Both of these guys were coming from a mathematical perspective,

0:09:04.702,0:09:07.255
but Turing told us something very important.

0:09:07.255,0:09:10.190
He laid down the mathematical foundations

0:09:10.190,0:09:12.303
for computer science, and said,

0:09:12.303,0:09:15.490
"It doesn't matter how you make a computer."

0:09:15.490,0:09:17.368
It doesn't matter if your computer's mechanical,

0:09:17.368,0:09:21.778
like Babbage's was, or electronic, like computers are today,

0:09:21.778,0:09:24.582
or perhaps in the future, cells, or, again,

0:09:24.582,0:09:27.728
mechanical again, once we get into nanotechnology.

0:09:27.728,0:09:29.765
We could go back to Babbage's machine

0:09:29.765,0:09:32.341
and just make it tiny. All those things are computers.

0:09:32.341,0:09:33.973
There is in a sense a computing essence.

0:09:33.973,0:09:35.978
This is called the Church–Turing thesis.

0:09:35.978,0:09:38.645
And so suddenly, you get this link where you say

0:09:38.645,0:09:40.868
this thing Babbage had built really was a computer.

0:09:40.868,0:09:43.693
In fact, it was capable of doing everything we do today

0:09:43.693,0:09:48.525
with computers, only really slowly. (Laughter)

0:09:48.525,0:09:50.631
To give you an idea of how slowly,

0:09:50.631,0:09:54.470
it had about 1k of memory.

0:09:54.470,0:09:57.388
It used punch cards, which were being fed in,

0:09:57.388,0:10:03.148
and it ran about 10,000 times slower the first ZX81.

0:10:03.148,0:10:04.751
It did have a RAM pack.

0:10:04.751,0:10:07.930
You could add on a lot of extra memory if you wanted to.

0:10:07.930,0:10:10.256
(Laughter) So, where does that bring us today?

0:10:10.256,0:10:11.864
So there are plans.

0:10:11.864,0:10:14.797
Over in Swindon, the Science Museum archives,

0:10:14.797,0:10:16.491
there are hundreds of plans and thousands of pages

0:10:16.491,0:10:19.960
of notes written by Charles Babbage about this analytical engine.

0:10:19.960,0:10:23.921
One of those is a set of plans that we call Plan 28,

0:10:23.921,0:10:26.075
and that is also the name of a charity that I started

0:10:26.075,0:10:28.809
with Doron Swade, who was the curator of computing

0:10:28.809,0:10:31.048
at the Science Museum, and also the person who drove

0:10:31.048,0:10:32.478
the project to build a difference engine,

0:10:32.478,0:10:35.036
and our plan is to build it.

0:10:35.036,0:10:38.902
Here in South Kensington, we will build the analytical engine.

0:10:38.902,0:10:40.904
The project has a number of parts to it.

0:10:40.904,0:10:43.424
One was the scanning of Babbage's archive.

0:10:43.424,0:10:45.346
That's been done. The second is now the study

0:10:45.346,0:10:48.456
of all of those plans to determine what to build.

0:10:48.456,0:10:52.900
The third part is a computer simulation of that machine,

0:10:52.900,0:10:55.823
and the last part is to physically build it at the Science Museum.

0:10:55.823,0:10:58.399
When it's built, you'll finally be able to understand how a computer works,

0:10:58.399,0:11:00.233
because rather than having a tiny chip in front of you,

0:11:00.233,0:11:02.843
you've got to look at this humongous thing and say, "Ah,

0:11:02.843,0:11:06.178
I see the memory operating, I see the CPU operating,

0:11:06.178,0:11:10.045
I hear it operating. I probably smell it operating." (Laughter)

0:11:10.045,0:11:12.644
But in between that we're going to do a simulation.

0:11:12.644,0:11:14.401
Babbage himself wrote, he said,

0:11:14.401,0:11:16.019
as soon as the analytical engine exists,

0:11:16.019,0:11:19.723
it will surely guide the future course of science.

0:11:19.723,0:11:21.568
Of course, he never built it, because he was always fiddling

0:11:21.568,0:11:23.650
with new plans, but when it did get built, of course,

0:11:23.650,0:11:27.160
in the 1940s, everything changed.

0:11:27.160,0:11:28.983
Now, I'll just give you a little taste of what it looks like

0:11:28.983,0:11:31.616
in motion with a video which shows

0:11:31.616,0:11:36.210
just one part of the CPU mechanism working.

0:11:39.210,0:11:42.209
So this is just three sets of cogs,

0:11:42.209,0:11:45.031
and it's going to add. This is the adding mechanism

0:11:45.031,0:11:47.688
in action, so you imagine this gigantic machine.

0:11:47.688,0:11:48.847
So, give me five years.

0:11:48.847,0:11:51.191
Before the 2030s happen, we'll have it.

0:11:51.191,0:11:54.161
Thank you very much. (Applause)