Wednesday, February 20, 2013

Meeting Lynn Conway


I can clearly remember the evening in late 1999 when the very first email from Professor Lynn Conway plopped into my inbox.

In those days much of my spare time was consumed as a vice president of the Press for Change campaign, doing advocacy work, editing the campaign's fast growing web site, and responding to requests for help and advice from the people who found us that way.

Lynn Conway's email was  out of the ordinary though.

First contact

She introduced herself as a trans woman who had been living in what's called 'stealth' for over 30 years.

She had a whole career without anyone being aware of her trans past. She had achieved a great deal that way.

Now, with retirement ahead, she was tentatively coming out and planned an information site to explain both her past and provide supportive information to counter what she saw as an industrial scale of lies about women like herself.

In her online searches Lynn had found us. She liked our factual and educational approach and wanted our advice and support to publicise what she was doing.

It was the beginning of a long association from afar.

It was an association which, after all these years, I was finally able to turn into a face to face meeting two weeks ago whilst passing through Chicago.

Coming Out

In our first exchanges Lynn explained how the decision to "come out" and explain about both her hidden career history and her transsexual past was prompted by the realisation that other engineers and journalists were beginning to display an interest in projects she had been associated with at the computer giant IBM in the mid to late 1960's.

Rather than face the possibility of people discovering her work and then tracking her down in some grand exposé, in a way she wouldn't be able to control, Lynn had made the calculation that it was better to seize the initiative, and explain her work to the researchers. It was a chance, finally, to step up to claim her part in a supercomputer project that was cancelled, and for her to explain an important invention which had then been buried by events until being 'reinvented' many years later.

Genius designer

Prior to her gender transition, Lynn had been employed straight out of college as a computer hardware design engineer, working in a special division of IBM, designing what was hoped to be an advanced supercomputer architecture. She was a major talent, with a tenacious approach to problem solving and an amazing ability to think 'outside of the box'.

In the course of her work Lynn tackled one of the fundamental problems of high speed computer design at that time.

Computers normally execute instructions one at a time in sequence. The top speed of any computer that works that way is determined by the physical limits of how fast instructions can be retrieved from the computer's memory, interpreted, and then executed by the arithmetic processor that lies at the heart of the machine.

Other engineers had invented techniques that chipped away at the edges of this problem. By fetching and storing instructions ahead of when they are required and storing them in a small special (expensive) 'cache' memory, the fetch time could be reduced. By breaking down the steps to execute an instruction, fetching the data to be processed whilst a previous instruction was being calculated, a little more time could be saved.

However, Lynn went for the jugular. She realised that the real speed advance would come if several instructions could be processed at the same time, in parallel rather than in sequence. It was a monumentally tricky problem. The approach fails if one instruction depends on the result of the calculation in a previous one. Ultimately, the calculation must turn out as though executed in the order the programmer intended. Computer programs also regularly branch off to new sets of instructions too. When that happens you can't so easily predict the necessary instructions to execute in advance.

Only a certain kind of mind can approach a problem like this. Lynn had that kind of brain. And her design for 'Dynamic Instruction Scheduling' was just the breakthrough to go at the heart of an ambitious supercomputer project.


Big companies are full of politics and rivalries though. And Lynn was contemplating a personal move that would rock the senior management of the deeply conservative IBM.

Moves were afoot by one team of rival managers to cancel the supercomputer project that Lynn was working on. And the crunch showdown battles happened to coincide with Lynn having announced her intention to change gender. She was suspended whilst the company decided what to do about her transgender revelation. This meant she wasn't around to help with the fight for the advanced computer system project.

And because Lynn wasn't around, the company also missed the incredible invention she had made … buried inside the design of the overall computer. The patents department had also not understood the import of her design either. Basically, this was a company sitting on something that would have transformed its fortunes competitively. IBM computers with Lynn Conway's super-fast central processing engine would have left every other machine standing. Yet even her colleagues didn't properly appreciate the enormity.

The super computer project was scrapped and this made the decision to 'let go' the sexually peculiar engineer simple to carry through.

And that's where the history of Dynamic Instruction Scheduling could have remained.

Poor Lynn didn't fully appreciate all these details at the time. She certainly couldn't understand how IBM could have overlooked the pearl in the wreckage, now archived away in the company's paper vaults. It is only today, as she collaborates with former colleagues on a memoir of this remarkable period, that she has been able to piece the story together.

You can read the results of that forensic investigation in a newly published paper here.

(Don't let the title or the technical parts put you off, it is a fascinating study of corporate intrigue, transphobia and incompetence).

A new career

Lynn Conway's career could have ended there. However, when you meet her you realise just why it didn't. This is one incredibly determined woman.

Lynn went away from IBM. She obtained the surgeries and treatments she needed to complete her gender transition. And then she began again.

Having realised in those days (at the end of the 1960s) that nobody would employ a trans woman in any seriously responsible work, Lynn had to make her way in a completely new life. She would have to build a career without any reference to her past, as that would have revealed her transsexual background. She couldn't rely on her college qualifications. She couldn't refer to her work at IBM. She could only start at the bottom.

This reboot of her career is explained in detail again on her web site. Bear in mind that when she wrote this Lynn expected that the only person who could really be relied upon to tell her story objectively was herself. Many trans people (including myself) will identify there.

To cut a long story short, a talent like Lynn Conway's is hard to keep in a box. From a modest job as a programmer she joined the heady environment of the Xerox Palo Alto Research Centre (PARC) at the time when a technology revolution was getting underway. This is the place where talented young people came up with the ideas for graphical computers … with windows, icons, mice and pull-down windows.

Another major invention was on the horizon too … the Very Large Scale Integrated circuit. Lynn found herself partnering with a physicist called Carver Mead. He knew how to build basic electronic components at microscopic scale on wafers of very pure silicon crystals. But the problem that stood in the way of exploiting the potential of that technology (on which our lives depend these days) was the need for a whole new paradigm of circuit design.

Without getting too technical, electronic engineers in those days were used to designing things with either discrete components (transistors, resistors, capacitors, etc…) or simple arrays of basic logic chips, where you connect the outputs from one device that performs a function to the inputs of another.

Designing for very large scale integration required a different way of thinking. It was completely beyond classically trained engineers. You could not design chips without understanding the microscopic details of how fundamental components are made, layer by layer, in the silicon. If engineers needed to learn this then very few would be able to exploit the potential for massively complex designs in a tiny space.

Once again, this was the sort of problem which Lynn Conway's mind was perfectly adapted to solving. Working in partnership with Carver Mead she came up with an approach for designing in building blocks that engineers could easily grapple with. She designed a training programme so this approach could be taught in universities. And the two came up with a technique that allowed engineers on those courses to try out their designs for real. It was the world's first e-commerce system, where engineers could submit their designs and have them made in sample quantities to order.

The outcome of these innovations changed the world for all of us.

In the first few university courses young engineers prototyped chip designs which enabled whole new businesses to be created: the giant corporations Silicon Graphics and Sun Microsystems were among those which stared in Lynn's classes.


This time Lynn wasn't about to be booted out of her job, so a degree of recognition has flowed in the years since.

However, being a woman has also meant that Lynn experienced a phenomenon that other female engineers may have encountered. There has been a tendency, over the years, for the work of one partner to be elevated at the expense of giving proper credit to her own. Carver Mead has gone on to receive many more awards, whilst Lynn soon started to be forgotten or dismissed as his 'assistant'.

This, again, feeds into Lynn's determination to ensure the history is told fairly and completely.

The first step to telling her story was Lynn's own VLSI Archive.

Four years ago, Lynn also gave an interview to me in which she talked about her work.

Then David Hodges, the Daniel M. Tellep Distinguished Professor of Engineering Emeritus at U. C. Berkeley, invited Lynn to write a memoir about the VLSI revolution for a special-issue of IEEE Solid-State Circuits Magazine. In this she wrote her own reminiscences of how the revolution came about and the paradigm shift involved.

A contemporary from those days, Chuck House, writes, "A Paradigm Shift was happening all around us". One of the pioneers of modern TV and camera sensors, Carlo Séquin, writes that "it was the charisma and enthusiasm of Lynn Conway that drew me into the environment" ("Witnessing the birth of VLSI design").

Remember, this is the story of someone who changed ALL of our lives. Practically everything we use nowadays depends on tiny, low cost, high volume VLSI chips. Many products simply wouldn't be economically viable any other way … or portable. Mobile phones, desktop and laptop computers, cameras, flat screen televisions, and most of the electronic equipment used in modern medicine. The chip is so ubiquitous that it is hard to remember the world that existed before … when computers filled large rooms and required enough electricity to run a small town just to power them.

The more Lynn Conway and her co-investigators reveal the history of how that all got started, the more people are bound to ask why someone like her is not a household name. Writing in the same special edition of  the IEEE Solid-State Circuits magazine Ken Sheppard describes the phenomenon as "Covering".

Meeting Lynn Conway

I am lucky that my own computer science training equipped me to appreciate the enormity of her contribution to society almost straight away.

My Professors at University taught us students about high performance computer design in the early 1970's, and they built amazing prototypes such as Manchester's MU5 research computer. But MU5's central processing unit, advanced as it was, was not a scratch on the designs Lynn had laid down at IBM several years beforehand.

As a software research student, I clearly remember my friends who went on to do engineering research having copies of Lynn Conway and Carver Mead's book on their desks. They dreamed of having access to the prototype manufacturing capability she was providing to US-based engineers.

As online collaborators, my contacts with Lynn Conway after her approach in 1999 concerned a transatlantic movement to change the status of trans people - a challenge she approached with the same forensic style of thinking. We faced different challenges in our respective countries but, at times, the threats were global. We shared ideas. We planned strategies to counter the lies about our lives.

Yet never in that time did the opportunity arise to meet my distant friend. I visited the United States periodically on business, but it's a big place. Opportunities never presented themselves.

This month, however, I needed to travel to San Francisco for a conference. And, because I didn't want to fly straight back from such a distant destination, I came up with the idea of travelling across the US, coast to coast, by train. The trains connect in Chicago … tantalisingly close to where Lynn is retired in Michigan. My itinerary required a two day stopover. This was a once-in-a-lifetime opportunity to meet a remarkable woman.

Long drive

The first surprise was how readily Lynn agreed to meet me. There is no such thing as a short drive in the US. Simply getting from her home to my hotel in Chicago's business district would require her to drive non-stop for three hours. And to drive the same distance home. She also had a tight schedule which, at first, sounded as though it would confound us. In the end, however, everything just clicked into place.

Lynn turned up bang on time in my hotel's lobby on the Saturday morning, as arranged. She looked exactly as she does in all her publicity photos. And remarkably well preserved, given the fact that she had just recently celebrated her 75th birthday.

She is a quietly, but very intelligently spoken woman with a mind that seems just as incisive as I imagine it was in the 1960's.

The hours flew. She brought me copies of her publications, and patiently explained them to me. I asked questions. She corrected where necessary. Even when describing her brutally insensitive treatment by 1960's IBM, and the more insidious writing out of the history of VLSI, there was no trace of anger or bitterness.

I could see how Lynn was at first genuinely confused by the way in which her invention at IBM got overlooked. In fact, at the time, she didn't even realise that it had been missed. She says that, if she had known, she would have felt crushed.

I could see how it had begun to occur to her that her steady erasure from VLSI history for two decades had parallels in the historical experiences of other very clever women. I could see how this very analytical mind was doggedly determined to explore any gaps she found in the account. Gaps gnaw at her. She needs to explore and explain the unknown. It is her instinct as an intellectual. She won't let go. It is what drove her to the two great contributions of her life.

We talked long and deeply. I bought her breakfast whilst I sipped tea in the hotel's café. After a while we had to move as the staff needed the table. We carried on in the lobby.

We talked for over six hours in the end. And neither of us really wanted it to stop. Me, fascinated with the first hand account of a real life heroine of the modern age. She, I guess, just pleased to have someone bright enough to understand her story and ask the right questions.


At the end it was dusk and I worried about a 75 year old woman driving three hours home in the dark through icy Illinois and Michigan roads. I shouldn't really have concerned myself. Lynn evidently looks after herself and all her faculties are very much there. I can only hope that I can manage to be as fit when I reach her age. I'm also sure she has the capability to achieve her last big mission now, which is to tell the whole story, and to draw attention to the phenomenon that obscures the contributions of great women.

We walked together two blocks to the garage where she had parked her car. We hugged and kissed. The standard kind. And then, as though on an impulse, Lynn gave me another longer, harder, hug. It marked a long distance friendship of more than 13 years, formed from a common interest. The recognition between people with one big experience of life in common, if not the rest.

I turned and walked away under the elevated railway to catch some sightseeing, simply amazed by the meeting I had just had. I didn't want to linger and see her drive away. I wanted to keep that special moment.

I am so glad I met her. People ask what sights I saw when I visited Chicago. In truth I visited none. A lengthy walk around the streets was all I had time for.

But I had spent the day talking to a woman who changed all our lives.


Tom Oakley said...


Jamie Angus said...

Hi Christine,
I was studying Electronics in the early 70's and decided to to do my PhD on designing a DSP Computer to learn about this newfangled Microprocessor stuff. Lynn's book on VLSI design came out just as I was finishing my research period and, despite it's cost, I bought it and was inspired by it. Thus imagine my surprise in the early 2000's when I discovered that she was transgendered and thus had already gone down a road I was struggling to understand!
I envy your opportunity to talk to her, and you are right her contributions have been awesome and have changed our world.
Jamie xx

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