documents,

made us think it would be a good idea to pursue the question of how to build what came to be called the paperless office.

[CoNTiNUed FroM p. 112]
You’re talking about robert Taylor,
who managed the Computer systems
Laboratory at parC.

did you have a sense of how revolution-
ary alto was as you worked on it?

Oh, yes, we knew it was revolutionary. We built it with the very first semiconductor dynamic RAM, the Intel 1103, which was the first memory you could buy that was less than a tenth of a cent a bit. As a result, we realized we could build a display that was qualitatively better than what we had at the time. We had character generator terminals, and some of them were quite nice. But they were limited in various ways, whereas the Alto had the property that anything you could represent on paper, you could put on the screen. We knew that was going to be a big deal.

You were also involved in the invention
of the ethernet.

The Ethernet grew out of the realization I had of how to provide a network for the Alto. We had been studying the ALOHA network, a radio network that was used to connect the various Hawaiian Islands. The limitation was that when a transmitter started to transmit, it could no longer receive anything. One night I was lying in bed thinking about the problem when I had this sudden realization that if you used a more limited media, say, the coaxial cables used in cable television, the transmitter could not only hear what it transmitted, it could also tell whether what it thought it put on the wire was the same as what actually got put on the wire.

so if another transmitter was interfer-
ing, it could drop back and retransmit
later.

“the alto had
the property that
anything you could
represent on paper,
you could put on
the screen. We knew
that was going to
be a big deal.”

That idea was refined by Bob Met-calfe and Dave Boggs into what we knew as the Ethernet. Of course, the Ethernet in those days was quite different than it is today.

 

You joined Microsoft in 1997 to help establish the company’s research lab in Cambridge, england, and were later involved in the development of the tablet pC, a subject that’s much in the news of late.

The line of thinking about tablets actually started at DEC [Digital Equipment Corporation]. We built a tablet called Lectrice back in the early 1990s, primarily as an electronic book reader. When I returned to the U.S. from my two-year assignment in Cambridge, I was working with a group in Redmond that was trying to build an electronic book reader. That didn’t work out too well, but it evolved into the idea of building a tablet PC. Of course the view there was it would be great to have a device that didn’t require a keyboard.

what do you make of the persistence
of the keyboard in spite of the alterna-
tives that now exist?

Typing is so much faster than virtually any other way of entering information into a computer, so I don’t expect that to change. There’s only one thing that can be better, and that’s to use a different set of muscles—the tablet allows you to do that. You’re holding a stylus and writing or drawing with it, and the interaction can be faster.

More recently, you’ve been working on
multicore systems.

I’ve been using field-programmable gate arrays (FPGAs) to explore multicore architectures. For a long time, it was impossible for academic researchers— or even people working in industrial labs—to design their own chips. It’s now possible to build a nontrivial multicore computer, with something on the order of 15 cores, on a single FPGA on a board that’s available for $750.

what does the future hold for you in
terms of research? are you tempted to
go back and continue working on the
tablet pC?

If I have a good idea I might go back to it. But right now I’m quite happy with what I’m doing, and there’s a considerable amount of work to do in this area. So I think I’m set for the next few years.

 

Leah hoffmann is a brooklyn, ny-based technology writer.

© 2010 ACM 0001-0782/10/0700 $10.00

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