The idea was that this was going to be the Bell Labs
memo that never was. It would never be released,
so said the lawyers, because it was too "sensitive".
For 33 years this was
all that we had and I suppose, in modern parlance, it became a sort of
"Reverse Engineering Jailbreak" as you might say
Many of you know -
far better than I do already - about the two big heroes of
Dennis Ritchie and Ken Thompson. There's a third person we're going to bring in today,
and the one, if you like, at Bell Labs, that I know really, really well, for
more than
thirty years now. That of course is Brian Kernighan
and I think, if only from this book here,
those of you who haven't heard of him may suddenly say " Oh! yes".
Probably the third best known person in the UNIX firmament
after Dennis and Ken. One of the suspects you'll recognize straight away is me;
the one on the far right is my colleague Steve, who features later on in this story
and the person in the middle there, the bearded gentleman,
is Brian - Brian Kernighan. That's taken about three years ago when we visited
Brian and it's in a coffee shop just off the main campus of Princeton University.
When you looked through the Version 7 UNIX manual
the thing that really struck you was that at Bell Labs. they not only
could afford PDP11s, VAXs and all sorts of stuff
but they could afford typesetters.
It's hard to realise nowadays what that meant.
Laser printers had not been invented.
At best, if you were lucky, you could get a good
- if you like - dot-matrix printer effect, but actually getting
Times Roman, Courier, Zapf Chancery,
Helvetica, Arial, whatever turns you on. No -
that was not in the compass of normal mortals because it cost a
heck of a lot of money. So what we're going to take a look at today
is how and why Bell Labs. had typesetters, what they did with them
and how they really were instrumental
in making typesetting democratic for the rest of us.
It was very early work but it was massively influential
and one of the people who led the charge on that - because he did a lot of the work himself
and he was kind of, informally, the leader
of the typesetting software efforts at Bell Labs, was
Brian - Brian Kernighan. Bell Labs' choice of
third-generation typesetter would "only" cost
fifty thousand dollars, in 1979 money,
which is just horrendous to think of.
By comparison you could easily buy a house - you could easily buy a house for 50,000 dollars
- and a really very good one I would think. They looked
long and hard at what was available and decided
that they would go with Mergenthaler
and this machine - UK designed - was called
the Linotronic 202. This was there
one step before laser printers came on the scene.
Naked Mini, two floppy-disk drives, control console,
paper tape. Here is a board
from the Naked Mini, and it shows you,
very definitely, how solidly
"minicomputer" the computational facilities were.
And there's all of the boards that comprise the Naked Mini,
receptor cassette, fed from bromide paper
at the back. Hidden under there a hi-res
cathode-ray tube, 972 dots to the inch,
and shaped a bit like a letterbox in many ways.
You exposed the bromide paper
in bands. And when you finish doing the current band
you mechanically move the bromide away from it. At huge cost, from either
Linotype or some other supplier, you bought a bromide
or film processor. You took along your cassette,
you fed it in to the end of this thing, which had three separate tanks
smelly developer, ugh!,
yes I can smell it even now, wash water
in the middle, after the developing was done of the image,
and then, of course, fixer at the end. And the fixer smelled the worst of all -
a sort of faintly acidic smell about it.
Then it came out at the end - it probably had another wash at the end
and then it went through a dryer or you hung it up to dry.
And then finally you got your beautiful bromide output, which you could
slice up and make it into page-sized slices
What you then did with it was, if you just wanted to send
a proof of what you'd typeset
out to all your friends, there were of course Xerox and other photocopiers around.
You could photocopy the bromide output
but if you wanted really high quality
and you were doing a long print run what you would have to do, at this generation,
was to send your photographic output off to a plate maker
that would convert your photograph into
an offset-printer metal plate. The idea is
you have a plate on a cylindrical drum which rolls round and round at
very high speed and can print off tens of thousands of copies of
things like newspapers or whatever. So that's
basically the technology behind
third-generation, cathode-ray tube driven,
typesetters . And, as far as Bell Labs was concerned, it just changed everything
because with the ability
to be imaging onto a cathode-ray tube
you could not just have the ability to use preset
fonts, like in early generations, y'know letter S's
magnified to various sizes - you'd got all of that - but you'd have the ability to draw lines.
You could do primitive line graphics
and certainly Brian and others at Bell Labs really
really wanted to do that. They could see the potential straight away.
But in terms of getting the full value out of this, what they, naively perhaps, thought
shouldn't be too much trouble, was to ask Mergenthaler, very nicely,
if they would let them have the spec. for how the digital fonts were held on
floppy disks.
"Why?" said Mergenthaler. "Because we want to create our own" they said.
Well, I gather the roof fell in.
Total, total, total disbelief. "Why would you want to do that -
this isn't a machine for amateurs!" One example
of the fonts that they wanted was a set of
chess pieces. This is the time to bring in one of our other heroes
Ken Thompson, already mentioned in the previous UNIX video.
He was part of Brian's team for commissioning
the 202 typesetter. It was led by Brian himself, of course,
and crucially they also had a hardware man called Joe Condon - a
very talented hardware engineer. Some of you will know
that Joe Condon and Ken Thompson were famous, just before this era,
mid-seventies, for creating the Belle chess machine.
Ken was there as a sort of ultimate software guru, who was
mad keen to create his own chess font and also
very happy to get deep into the Linotron - as deep as was needed.
Merganthaler just said "I'm sorry gentlemen, it's a flat 'no'.
we are NOT going to reveal to you how our fonts are done.
Yeah, Yeah, we thoroughly accept you are Bell Labs, y'know, you have enough
hassle from anti-trust legislation; we know you are not gonna set yourself up
as rivals,
you're not gonna become just a font shop and, y'know,
do cheaper fonts than us. We know. We accept it." But nevertheless
there was a feeling - rightly, I think - in Mergenthaler
that this was like opening Pandora's Box.
Even though these three talented chaps at Bell Labs
were quite prepared to sign every non-disclosure agreement
going, the answer was firmly 'no',
absolutely 'no'. So
they basically said: "Well, we're going to do it anyway"
and I suppose, in modern parlance, it became a sort of "Reverse Engineering
Jailbreak", as you might say.
The wisdom from Mergenthaler was: "You'll never do it; our fonts are
not deliberately encrypted, but they are so compressed
and so compact, and in such such an obscure format, you will not succeed
in deciphering how we do it, or why we do it".
To which, I think, Brian probably muttered under his breath "What you don't know is
I've got a secret weapon
and it's not a piece of hardware - it's called Ken Thompson".
It took Ken, with some help from Brian - who always
underplays his own role in this - basically between two and three weeks
to get the overall idea of how it all worked.
It took about six weeks for total knowledge but that included
complete knowledge of exactly what the resolution was of that CRT,
the timings - everything. You just wouldn't have
wanted a more talented team to prove that this
could be done. They created their own fonts. Ken did his chess font - there
were no chess fonts available at this time. There's hundreds of them now.
In an email he sent to me, he said: "Well, I just wanted to do something really quickly
because I wanted to publish books and I wanted a proper chess font".
Hermann Zapf's Palatino - but there is
Ken Thompson's chess font in action. The whole of this book
all done on the Linotype 202.
So that is one of the rationales for wanting to be able to do your own fonts.
Brian and I have traditionally referred to this work, that he did
as The Vacation Project, right, because it was in the vacation period
in the middle of 1979 that they spent their six weeks
reverse engineering the 202. But when it came to the turn of 1980
Brian was absolutely adamant that he wanted to write a memo
about - not the fine details of how it had been done - but just the
overall picture saying "We did it - this is what we can now do,
isn't it wonderful?" Not in any way to be anti-Mergenthaler
although their [Bell Labs'] version of the 202 was very, very unreliable
as you be able to read in this memo. We'll try and set up some
Web pointers for you as, part of this video, so you can read it for yourself.
But he just wanted to tell the story. Mergenthaler got wind of it and
basically said "No, absolutely no!" - got in touch with Bell Labs.' lawyers
and - to cut a long story short - it was suppressed.
The idea was that this was going to be the Bell Labs
memo that never was - it would never be released,
so said the lawyers, because it was too "sensitive".
But it was, with hindsight, a real pointer
to the future, when fonts would become commonplace
within the laser printer era, and so on. For 33
years this was all that we had as
the hard-copy evidence
of the technical memorandum. The thing I'm kicking myself for now is that I didn't
actually keep any bromide. I've got lots of other bits and pieces here,
I've got font books for the ... supplied with the
Linotype 202 but I didn't actually keep
any proper bromide and nor, it would seem, did Brian
because here - this isn't the bromide,
it's an nth-order photocopy of
the bromide - off the 202 - and you can see what happened. Every photocopying process
adds so many percent to the apparent boldness. Bits have got chopped off and
truncated off the bottom -
filing marks here.
However, as you turn over you can begin to see
just what was turning them on about the
abilities of the 202. For the first time using Brian's 'pic'
pre-processor they could draw a line diagram
of how it worked on the 202, look, cathode-ray tube
sixteen-bit Naked Mini driving it ... floppy disk ... character definitions on
... integrated line diagram output. Not stuff that you had to have drawn by an
artist and pasted in
and made a plate of, or whatever, afterwards. The governing
organization, if you like, for what's left of Bell Labs is now called Alcatel-Lucent.
So, I suggested to Brian and a good mutual friend, Chuck Bigelow,
typographer, said: "Yeah!, yeah! you guys ought to do this".
I said "Why don't we ask the powers that be for
permission - it's not sensitive any more 33 years after the event.
Please can we recreate the Vacation Memo,"
as we came to call it. The really big plus point of course
was that it was typeset in this typesetter version of that original 'runoff' program -
'troff' - the typesetter version of 'roff'. Troff can be equipped with macros to
help you do the layout, and all this sort of thing.
Anyway, to my amazement, I have got a more authentic,
and ancient, set of super-duper 'troff' macros for doing Bell Labs Memos
than even Brian had, so we were able with a fair bit of effort
to recreate the memo at the sort of quality
that would certainly have been obtainable from the 202,
if only we'd hung onto the bromides, yeah? But we didn't!
However, this of course has all been done via PostScript and PDF and
modern technologies. But we're trying as hard as we possibly can
to still retain the look and feel of what it would have looked like,
at best quality, coming off the Linotronic 202.
One of the best ways to show what we're up against and whether we succeeded or
not is to show an A-B comparison.
Here is the original memo - not as a bromide as it should have been -
but as a sort of nth-order photocopy of it. First of all
finished off properly at the bottom don't forget we didn't have the appearance
of this - we didn't save the bromide -
But what we did have was the 'troff' source code.
Brian had saved that, thank heavens. We would have been struggling without that
although, in the end, we could have rebuilt it with optical character recognition
and all that, but he'd saved the 'troff'.
So, instead of running 'troff' through a back end to the 202
we now run'troff' through another back-end out to PostScript and PDF.
So here we go - nice and clean. No ink
bleed - straight off a good quality laser printer ...
the Bell Labs logo revived as a font character
all over again, and even shrunk down.
It says here: "The most obvious special character we use is the Bell System logo"
I'm jumping ahead now. The thing that Brian was trying to get across in this memo
was this: in this era you mustn't imagine
that the 202 and its characters were able to do
splines and arcs and complex curves - no they couldn't.
I mean, quite apart from anything else - there wasn't the processor power
to be able to do the computer graphics necessary to turn those
into dots on the CRT fast enough.
No, what you had to do was to simplify and make all your characters be lots and
lots of small
line segments. so these diagrams here, as you can see, I've put little arrows on -
not really part to the character - just to emphasize to you this is where each line
segment begins and ends.
So, that Helvetica font letter 'e' is a bunch
of straight lines. And there were severe limits on how many you could have,
at most, of straight lines in any one character.
But it worked well enough, so long as you didn't take your character size above
about an inch,
at most, and then you began to be able to see
the straight-line approximations. The Naked Mini was going flat out, and even then it could
just about cope with characters done
as lots of straight lines. It certainly could not cope with
arcs and splines. OK - so let's just summarize the two big challenges that we
faced in
recreating this vacation memo. Fonts like Times Roman
Helvetica, Courier - if they're there - are no problem.
They existed on the 202 but they've been brought forward into the PostScript and TrueType,
modern fonts era. Those are easy to get hold of
The harder bit, here, was what we had to recreate
because they just didn't exist except on the 202.
The first and most obvious is Ken's chess font, so starting from first principles again
I created a few shapes using Brian's 'pic'
program and handed them over to my colleague Steve, whose photograph
you've already seen - Steve Bagley. We also discovered, by the by, in doing this
that Ken Thompson, faced with the problems of fonts on the 202,
where individual characters shouldn't get too complex -
you'll never guess how he did something like
a pawn here, on a shaded black background. The overall character would have been
too complicated
so what he did was he created extra characters which was
the cut-out shape at the back, partly shaded,
and then dropped the pawn shape on top of them as a zero-width character. So it's
a superposition.
We were authentic - we did that in our replica
The other thing which caused me many sleepless nights is that
the Linotron font for doing
program printouts - 'Courier' if you like -
was called Printout. Heaven knows why Linotype,
Merganthaler, didn't just do Courier but they didn't.
Next thing to do is to phone up the Font Shop in Cheltenham and say:
"Printout, on the 202? It's been turned into PostScript hasn't it?
By somebody? For some reason?". "Er, no", comes back the
reply, "It was 202 only. We never converted that one."
So we decided to recreate it.
In conjunction with my friend, Chuck Bigelow, type designer,
we had a look at this Printout font in the
Linotype font book. Chuck took one look at that and he said: "That's come
from a variable-width typewriter font - something like Excelsior
but they've hacked it about to make it a fixed-pitch font like Courier".
And he's quite right. If you look at the tiny details you can see it's Excelsior
messed about with. So with a sinking heart
I started off with Excelsior. I spent - I'm not exaggerating -
120 hours chopping stems
chopping down serifs, resizing, placing
in fixed-width character positions, trying all the kern-pairs I could, to get them to
look right.
It's not bad. I'm still not happy with it at all.
But it was a revelation to me as to just how
incredibly labour-intensive type design is.
But for the sake of authenticity, and when you look inside the vacation memo you
will see,
Brian wrote a heartfelt letter to Mergenthaler
about the lack of reliability of their 202. And he wrote it in
the Printout font, so I wanted it to look right.
So, that just about summarizes, I think, the
big two challenges that we had to overcome
and I think we've now just about completely succeeded.
It's like restoring pictures. You don't want to over-restore.
You want to use exactly the original materials
and do it just right. But overall I'm pretty happy - I don't think we did too badly.