An Interview with Pat Crowley
PC = Pat Crowley
GAM = George Michael
GAM: Today is May 17, 1995, and it's my pleasure to interview another Lab
pioneer named Pat Crowley. Pat, why don't you
just begin by telling us where you came from, and when
you got to the Lab, and so forth.
PC: I went to school at San Diego State College from '53 to '58. I was working
in math and physics and I married Barbara Killian there
in 1956. And, somehow, she got an interview with
someone from the LabI think it was Bill Thompson who
arranged for us to come up and be interviewed, which we
then did. Then somehow they were blinded by
something, and hired both of us! Barbara went into the
Rover Project, and I went into Theoretical Physics, which
was then headed by Mark Mills. Just before I started
there, Mark died in a helicopter accident overseas.
GAM: Yes, in the Pacific. That happened in early April, 1958.
PC: Yes. So Sid Fernbach took over as Acting Head of Theoretical Division at
that time. I was supposed to work in the Hydro Group. I
think when I was interviewed, I said I was interested in
"acoustics", and they got that confused with
So, I was supposed to work in the hydro group, which was headed by
George Bing in those days. George didn't do any hydro;
he was looking at reentry problems and stuff like that.
Bob Lelevier, who had been in the hydro group, had left
the Lab by that time. I was supposed to work for Bill Noh
who was developing a 2D, Eulerian hydro code; I was
supposed to help him. But I didn't know what I was
supposed to do, and he didn't know what he was supposed to do!
The programmer was Isabelle Blanford and she called that code GOLUX
after the little man in Thurber's "Thirteen Clocks," who
said "I am the Golux, the only Golux in the world, and not
a mere device." Izzie was one of the best programmers at
the Lab. She left in a couple of years, and went on to
become a lawyer or something like that. I don't know
I've lost track of her.
GAM: Actually, she went on and became the wife of Fernando Corbato at MIT. And then, unfortunately, she died.
PC: Oh, did she really? That's too bad.
GAM: It was very sad.
PC: The person who took Izzie's place was Shirley Campbell, who had one of
the most remarkable brains I've ever seen for keeping
track of everything. She knew every line of code and
where it was. She was a chemist by education, and a
remarkable programmer. She was just really, really
In those days, you know, we didn't have computers in our offices. We had
to go over and sign up for machine time. So you got a 15-minute shot,
and that's all you got each day. Maybe you
got two shots a day; you could negotiate with somebody
else for an afternoon shot if you couldn't figure out what
to do in the morning. You had to figure things out during
those vital 15 minutes. At the end of that time slot, you
probably got a memory dump, which you used to then
figure out what went wrong so you could go on to the
next 15 minute time. And, like as not, the memory dump
was in Octal, which meant you got to convert Octal
numbers into whatever number system worked for you
without a hand calculator. You learned how to do it by
hand. Interactive computing has really changed the
world! Then, finally, they gave us double memory dumps
or something like that.
GAM: Apropos of how octal can get into your subconscious, here's an amusing
anecdote about Izzy. It seems she was serving as a
navigator in one of those Sport Car Rally things; a
"Gymkhanna" or whatever. Anyway, she and her driver
thought they would win something because they weren't
making any mistakes. When they got to the finish line,
they found they were almost in last place. It seems Izzy
had done all her time calculations in octal.
PC: I remember those competitions, many Labbers competed; they were fun.
I've got some names written down here. Seymour Sack
was also in the hydro group. We were in the original
Building 162, which had two mature palm trees out in
front, they tore down the building and tore out the palm
trees, much to my disgustwhen they built the new
GAM: Yes. It was unfortunate.
PC: Building 162 had been a hospital, or something like that, when it was a
Navy base, I think.
GAM: BOQBachelor Officers' Quarters.
PC: Oh, was that what it was? All of Theoretical Physics and some of A
Division, and B Division, were located in that building.
During the summer, air conditioning amounted to a fan
and an open window. Those of us who were fortunate
enough to work on the computers could go to the
computer room to cool off. The computer room was
always nice and cool. So, we had all kinds of
opportunities to get in an extra debug shot
when someone didn't show up.
I just had one little remembrance of the 15-minute time slots. We had time
cards. And when you got off, you punched out. The usual
thing was we set sense switch 1, and that was supposed
to initiate, by convention, the program's getting off. A
minute or so later, the program would end, and we
would punch out.
Well, Jack Trullio, who usually had the slot ahead of me, whenever he
threw sense switch 1, he punched out. So, there was a
minute of his time that I paid forevery day,
consistently, he did the same damn thing! It didn't matter,
but it was annoying to me.
One of the things I remember about those days is thatwhen you got up
to a 704 or something like thatmemory was about 4,000
words and I think those were 36-bit words.
GAM: Yes, and the later 704s had 8K and 16K words of memory on them.
PC: But didn't the early ones just have 4K?
GAM: Yes. Both the 701s and the earliest 704s.
PC: I didn't work on the 701s. The 704s had 8K words. When you were doing a
mesh calculation, like a hydro calculation, you wrote the
mesh out on tapes. Then you would read in part of the
mesh off of one tape, and compute on the middle of that,
and then write it out on another tape. Then, when you'd
get all done, you'd have to rewind the tapes. And you
couldn't do any computing during the rewind.
Then, Norman Hardy came up with the three-tape scheme, which
eliminated the latency due to rewind. He had them
arranged so that while you're reading one, and writing
one, you're rewinding the other one. A marvelous little
GAM: Well, Norman is just a genius, you know.
PC: Yes, I think I've known two geniuses in my life. One of them was Norman,
and one of them was Chuck Leith. And, I don't know,
maybe I've known others, but those are two who I know
GAM: Yes, you're right. I agree.
PC: If your program is 2D hydro, what you end up with is a bunch of numbers,
and the raw numbers don't make much sense as such.
Well, one of the things you'd like to see is how the fluid
flows. And so it seemed to me that the right thing to do
was to make up a plotting package that, at any instant in
time, took a restart dump, and plotted what the velocity
field looked like at that time.
PC: To do that, I had to plot vectors. And what I started out with is a
hand-coded subroutine called "PLOTL" that Norman had
written. PLOTL was a tightly written thing, with
absolutely no comments in it (PLOTL stands for plot-
line). It used such exotic things as unnormalized floating
adds, and all of that. So the first thing I had to do was to
figure out what Norman was doing in that routine, and
then I had to figure out to put the head on the arrow. Alex
Cecil helped me a lot in doing this. Eventually, it worked,
and we called it PLOTV, which I think still exists to this
A lot of this, remember, was being done late at night. The machines were
supposed to be used for production at night, but we just
went in and took our debug shots. So, we got maybe
several debug shots per day. We'd go home to dinner,
and then come back, and work from 8 or 9 at night to 2 in
the morning. And then we'd go out to the Hungry Truck
and have some pancakes or eggs or hash browns.
GAM: Physics is what physicists do late at night.
PC: I've heard you say that many times, George. And even when we were out
at the Hungry Truck, there we werestill talking about
computers and things. Chuck and Norman, and others,
were designing SOLOMON and, you know, it was a
I was uneducated when I got there, and the Lab really offered me
opportunity and freedom. And that was really nice. It's
not that way anymore, of course.
GAM: I'll say!
PC: But those were what we call "the good old days."
Eventually we had to write another version of this 2D code (GOLUX),
which then became CEL. Parts of the CEL were
Lagrangian and parts of it were Eulerian. The Lagrangian
meshes floated around and covered parts of the Eulerian
mesh. It was a fairly complicated code. All of that was
done without benefit of time sharing.
I guess the first timesharing that came along was GOB, which you, and Bob
Abbott, and Norm...
GAM: Yes. Well, there also was Shig Tokubo, and Cliff Plopper, and Ed Nelson.
PC: Shig was part of that. Do you remember the first editing routine was
NABwhich was Norman, Ann, and Barbara (Schell)?
PC: And what I remember was that somebody had the brilliant idea that all
these tentacles on the Octopus ought to go into one,
central location, which was a PDP-6. And when it went
down, everything went down. And when it came up,
everybody's office went "ring, ring, ring!"
GAM: On the Teletypes, yes.
PC: Yes, the Teletypes woke you up, and you madly went over and started
doing your thing. And then it would go down, and then it
would go "ring, ring, ring" again. I don't know how we
got through those stages.
GAM: We were all learning.
PC: Boy, I'll say we were! But we learned, we learned. And look at where that's
gotten us today.
GAM: You know, before we had time sharing, as you recall, I'll remind you that
we had a thing called CRT Batch. Do you remember that?
PC: Well, I don't remember. I remember we had batch processing.
GAM: CRT Batch was this thing that you and I put together, clumping all
the plotting routines together.
PC: Oh! Oh, the Library! The Library! Yes. Gosh, I'd forgotten all about that.
Oh, my God. Yes, and that contained vectors and contour
plots, which were important. There were some early
attempts at shading. But I remember shading didn't do so
well; there was always a problem with the seam at the
edges of the zones.
GAM: Well, we didn't have enough points in the raster for that. But, you know,
the Library's set of stuff lasted well into the '80s.
PC: Really? Is that right?
PC: Well, probably parts of it continue on today in some form or another. It's
been modernized, right?
GAM: Now we have better CRTs to work with, but the simple routines that let the
physicist get close to his data don't seem to be around as
PC: One of the other things we thought about doing was linking one physics
code to another. That is, you would run a problem at
early times on the Lagrangian code; (a Lagrangian code is
one where the mesh follows the fluid.) And then the mesh
would get tangled because the fluid wanted to have
vorticity and get all scrambled up. Then at that point, you
couldn't continue the simulation without rezoning. So
you would do an overlay calculation onto a Eulerian
code, or maybe onto a smoother mesh, or something like
that, and then continue on with the simulation.
To do overlay calculations, you had to do volumes of
intersections. And the earliest one was written by
Norman, of course, called VITVolume of Intersection of
Well, there was another guy who came along, and he wrote a code called
ZOVOLIZone Volume of Intersection. I thought that
was the funniest name for a subroutine I'd ever heard.
And that was Dick Bentley who was working in
T Division, and he was legally blind.
PC: There's a story about him going up in the mountains with a muleand he
was a little bit stubborn, tooto carry his stuff. But he
went backpacking by himself in the mountains with this
PC: You'd see Bentley sitting there at a keypunch machine, with his eyes about
three inches from the keyboard, trying to punch cards,
trying to debug this volume of intersection routine.
GAM: It worked, too!
PC: Absolutely! It worked for a long time, and it's probably still around in
some form. These were fairly sophisticated routinesfinding
the volume of intersection of two lines is easy
with pencil and paper, but when you come to doing it in
finite arithmetic, it's a bitch! It's very complex, finding all
the special cases, and getting them right.
For a person who's legally blind, it becomes an even greater achievement.
GAM: Quite an accomplishment, yes.
PC: Yes. I'd give him several stars for that. But he got it right, and it was one of
the things that let us do overlay calculations from one
code to another.
GAM: When did CHETZ come in?
PC: The name CHETZ was an acronym for "Continuous Hydro Eulerian To
Lagrange. It was written "CHETL" and so it was originally
pronounced "Chettle". And then that got transcribed into
CHETZ, because Ts and Zs and Ls looked very much
alike in my handwriting. But the idea with CHETZ is that
you could have a hydro code where the mesh would
always be a nice mesh, but the mesh would be moving.
And so, in parts of the fluid, it would have the accuracy of
a Lagrangian calculation, and in the other parts, it would
not get tangled, because it would move so as to be a nice
mesh. In the non-Lagrangian part of the mesh, the fluid
would flow relative to the mesh. We wrote CHETZ in the
early '60s or something like that. CHETZ was sort of an
early attempt at what's called the "ALE" techniques these
daysArbitrary Lagrangian-Eulerian, which was a name
coined by the Los Alamos people.
But you and I wrote this CHETZ code. And it ran some fairly interesting
problems as I recall. And then somehow it got lost on the
back burner someplace. I went off to school, and you
went off to do other things.
GAM: Well, you gave it to me, and I ran it. And we always had trouble, because it
wouldn't correctly run a shock wave in a pipe. So, it got
put onto the back burner while we tried to figure that out.
GAM: Then you went to school at Berkeley, right?
PC: Yes, I think it was '62 or something like that.
GAM: Yes, because I ran this on the STRETCH.
PC: On the STRETCH? When did the STRETCH come?
GAM: In '60 or '61.
PC: Okay, because I remember running some thingsI think I ran on the
STRETCH before I went back to school.
PC: And then I found myself in school, not thinking about how you do analytic
solutions to differential equations, but how you do finite
difference solutions. And the professors weren't
interested in finite difference solutions at all in those
days. So, I just daydreamed my way into coming back to
the Lab after a year. But I learned some hydro in school,
and I had a good time. So, Barbara and I were gone for a
year, and then we came back. She went into the
Plowshare Program, I think, at that time. When I came
back, I moved into another Hydro Groupthe H
Groupwhich was headed by Chuck Leith in those days.
Those were the days when Chuck was writing his atmospheric model,
LAMLeith's Atmospheric Model, as some said. So I still
didn't know what to do in those days. Maybe I still don't
know what to do now! But the Lab was still such that you
had a lot of freedom to do what you wanted to do. I think
the CDC 3600 was coming.
GAM: Right. Well, they had the 1604, then the 3600, and then the 6600.
PC: Okay, yes. Before we leave all of thatremember computer programs were
kept on punch cards. A large code might be several boxes
of punched cards, and from time to time people dropped
those boxes of cards.
PC: Roger DeBarr was carrying his KRAKEN code around, and dropped it.
GAM: Oh boy!
PC: Pete Moulthrop tells that story. When he dropped it they all slid out, you
know, nicely. And he just put it back together. And then,
rather than reading all the cards in everytime we had
alter decks. Do you remember, you could make alter decks?
PC: You could just read in a little deck and use it to alter the main tape. You
went from card-to-tape before you went on the machine.
You had your source code on one tape, and your alter
deck on the other. And you probably were writing in
FORTRAN, which was becoming more respectable in
those days. It still had bugs in it that had to do with
nested do-loops and things like that. Gosh, I remember
fighting some of those compiler bugs! We don't worry
about them so much any more.
GAM: No, compilers are a little more robust in that respect.
PC: One of the things I remember was making the STRETCH play music. That
was something that Norman was doing. He found out
that the STRETCH was broadcasting, and that by writing
do-loops of different lengths, you could make musical
notes by modulating the broadcast frequency. And so we
just tuned in a little FM radio, and listened.
PC: So, there were some Bach partitas, and all of these things done late at night.
And I don't know if anybodyit's probably illegal to
make recordings of thatdid anybody?
GAM: I think that Norman and Ted Ross did make a recording in Berkeley. They
had produced music like that by flipping a sense light on
a 709 or a 704 or something like that.
PC: Yes, yes. That was inside the do-loop, I guess, yes. It's amazing!
We also learned how to make movies. I don't know when that started.
GAM: Well, we started that in '56 and '57, but it got to be a much more elaborate
art in the '60s.
PC: When did the dd-80  come along?
GAM: In '61. We had this marvelous pulse-operated camera on itit could run
up to 30 frames a second .
PC: Right, yes. I made a movie routine that allowed you to watch your film
being made on line. This eliminated a few days wait for
film processing. Roy Woodruff, who was a designer in
those days would go over and sit in the machine room,
and watch the program as it produced the movie. That
facility got information in the designer's hands ASAPthey
didn't have to wait for film processing. Of course,
after getting the hard copy you could then show it to a
bunch of people. Roy wanted to see what was going on
right as it was happening.
PC: I remember taking math classes at the Lawrence Radiation Lab from John
Killeen from '58 to '62. I took several graduate math
courses from John, which didn't get me anywhere. I
mean, it got me some education, but I decided I wasn't
going to be a mathematician.
People at Livermore were starting to write large physics codes in the late
50s and 60s. Each physics code requires a generator and
an analysis routine. The generator defines initial
conditions and the analysis routines synthesize all the
billions of numbers into a few plots and numbers that
humans can understand. And each one of those three
efforts is a major code in and of itself.
PC: The people that I remember who worked on making generators were
Maggie Gee and Bob Cralle. And George, did you write
GAM: I did some of that, yes, but I wasn't completely involved in it. I had all
these other things I was screwing around with.
PC: Then, the output included some kind of integrals over time and over space.
I mean, these hydro codes had thousands and thousands
of numbers! And you can't just present the thousands and
thousands of numbers to somebodythey can't comprehend it.
PC: So, you either have to come up with some kind of integralssome measure
of goodness of how this thing is workingor you have to
make pictures, or some combination of those things. We
figured out how to make movies, and how to do integrals,
and how to present them, and how to do time histories,
and how to save data as we were computing so we didn't
recompute. These days, there are arguments about
whether you should just recompute, rather than save,
because saving is expensive.
GAM: But so is recomputing!
PC: But if you try to save an entire mesh in a 3D problem, that's a big...
GAM: Oh that's a bear.
PC: That's a bear, right, if you have to save everything. Well, there's always
been a tradeoff between recomputing and savingand I
don't know what the answer is right now. The guys who
do weather simulations...
GAM: Well, very early in the '60s, you were dipping into ocean modeling, weren't
PC: Haso to speak! Yes, when I came back and went into Chuck's group,
Chuck had written an atmospheric model. And so I
played around with toy ocean modelsocean model
basins and such. And then I decided that the best thing to
do would be to write a global ocean model, and then to
couple that to the atmospheric model. And I remember
writing the 3D, global ocean model with 5� zones. I think
there were eight levels in the vertical. In writing it, I
learned about some of the problems that were associated
with such a beast, such as its initialization. It turns out that,
in the atmosphere, after thirty days of model time
whatever your initial conditions arethe weather, the
fluid patterns start looking like real weather patterns.
But, the ocean has time scales that are much longer than that and the
initialization problem is one that, still, nobody has really
solved. It's still an active research topic.
And then the coupling problemhow to couple an atmosphere to an
GAM: Oh, yes.
PC: The 3D ocean model never did get coupled to the 3D atmospheric model.
But there was a 2D zonal model that went from the North
Pole to the South Pole, and had averages from east to
west; that got coupled, and some work was done there.
But it was still clear that the initialization problem was
GAM: It seems to me that I have some movies of those zonal flows.
PC: There were some movies made. And, again, the atmosphere always tends
to look like the atmosphere pretty early on, but the ocean
doesn't really settle downand maybe that's reality.
They find that the more they look at ocean circulation, the
more activity there is out there. So, who knows?
Some of the recent stuff that's been done when you try to couple
atmospheres and oceans is if you couple the fluxes, which
is the physical thing to do, then the models won't settle
down to anything realistic. So what you have to do is
drive them with fixed temperatures on the boundary
conditions, and then they'll settle down. Well, that
sounds to me like there's something wrong.
PC: It's possibly related to the initialization problem.
GAM: One of the things we did, as I recall, is we made some movies of the 9-point
operator and the 4-point operator, and so forth? Do you
PC: Vaguely. There are a lot of things that are vague these days! One of the
things I remember making movies of, and looking at, is
the number of significant bits that are needed to do a
calculation. And that shows up most readily in
instability-type calculations. That is, if a word only
contains 32 bits, then the round-off propagates up and
messes up the solution at a given time.
PC: Well, if you have more bits, even though the propagation occurs, it takes
longer to get up to mess things up. So, to do
things that are physically meaningful, you need at least
64 bits in a word. Tim Rudy and I did some stuff on some
zonal flow calculations, not instabilities, but just zonal
flow hydro, incompressible hydro, and looked at how
many bits were needed. And we found that the same
thing was happening there. We would always do the
primary calculation with 64 bits but, then, we'd rerun and
we'd shift off a certain number of bits, (throw them
away), and so do a sequence of experiments at 64 bits,
32 bits, 20 bits, and so on. And you could see that the
calculation broke down at earlier and earlier times as you
used fewer bits to store numbers.
GAM: As you say, that was expected. There was a
noisy mode on the STRETCH where the last bit could be
chopped or set, by the way a flag was set. And that's
where people started studying that. And they continued
the study on the STAR, because it had a 32-bit mode and
a 64-bit mode. So did the STRETCH, for that matter.
Generally, it was seen that 32 bits was not enough for our
PC: Speaking of the STARduring the time I was trying to be an
administrator, the STAR came along. I remember the
background to that is that Los Alamos backed out, and
there was a meeting at Livermore, and everybody in the
room except Bill Lokke said we should take the second
machine from Los Alamos. Bill said no. He was the
smartest person in the room at the Lab on that day.
GAM: He certainly proved to be right.
PC: But, we ended up with two STARS, and, my God, the number of people
that had to be pushed into getting the STAR to work at
any kind of efficiency was just amazing. The production
codes had to be ninety percent or
more vectorized before they'd run at more than scalar
speed. [Note added: the scalar speed on the STAR turned out
to be approximately half that of a 6600, a ten year older
machine.] But the amount of work that it took to vectorize
them was considerable. All the codes were
rewrittenand maybe that was a good investment.
GAM: Well, possibly. Jim LeBlanc said that for seven years he didn't get any
physics done. And he said, "Never again."
PC: Yes, I think that was true for a lot of us, but I didn't get any physics done
because I was working in administration in those days as
a Group Leader in A Division. But a lot of people who
should have been doing other thingsGeorge
Zimmerman probably paid the pricea lot of people
spent their time trying to get codes to work on the
damned STARs. That was one of the big computational
mistakes that the Lab madepoor, poor judgment.
GAM: I think it waswhether one is willing to admit or say itthe mistake was
getting two STARs, okay?
PC: Yes! Yes! Okay, yes! Getting one STARwe could have lived with one
STAR, but getting two! And then being told by energy
officials in Washington that, look at all this computing
power you have! Why do you need more? Use what you
have! While Los Alamos is going out and baggingI
don't remember what...
GAM: They got the CRAY 1.
PC: Some 7600s and then the CRAY 1.
GAM: Yes, they got extra 7600s while they waited for the CRAY 1.
PC: Yes. You know, they were getting all kinds of stuff. They didn't know
what to do with computers, but they were getting them!
GAM: Yes. They're still doing that!
PC: Well, I don't know what the link is there.
GAM: They have a huge stable of computers theremuch larger than oursyou
know, they even have one that they run for the Defense
Nuclear Agency (DNA). And the Army.
PC: Oh, really?
PC: Well, they got ahead of us in the parallel processors because Harold
Trease was pushing a lot of that.
GAM: Yes, and it seems like they got burned by that in the same sense that we got
burned by two STARsnot much came out of it in their case.
PC: Well, I don't think that was the same story. I think that may have had
to do more with people than with the machines?
GAM: Well, yes. But the difference may be that Los Alamos is economically, more
important to New Mexico than Livermore is to California.
In any event, the point is: It did not measure up to what
their expectations were.
GAM: And they still have a lot of parallel machines laying around the place, but
they're research, not production, machines.
PC: Yes. Well, aren't we trying to learn how to work with the parallel machines
GAM: That was the idea, but, you see, with the meddling that comes from
Washington, there's no opportunity to do that. They're
trying to turn everything into a production facility.
PC: You know, Chuck talks about message-passing versus FORTRAN 90. That
debate rages on, and probably will for a long time. I
would like to see everything done in the compiler, so the
guys could just write physics rather than worry about
message passing. Chuck told me that efficient message
passing is like doing buffered I/O. It's exactly the same
Oh, I have to go back just a little bit. We missed a computer, and that is the
computer that Chuck did most of his work on, the LARC.
The Remington Rand LARC, which was made especially
for the Labmaybe one or two in the world.
GAM: There were two.
PC: I don't know where the other one was.
GAM: At the David Taylor Model Basin.
PC: Oh, yes, that's right. And we had a LARC which had a FORTRAN that
nobody used because it was too clunky, I think, or maybe
too unreliable. So, everything we did on the LARC was
hand coded. Chuck's atmospheric model, my global
ocean model, Bernie Alder's molecular dynamics, and
Nevin Sherman's N-body problems.
GAM: In fact, he and Jack Noonan used it to find a logic error in the LARC
PC: Oh, is that right?
GAM: Right. It's a story I have to get. After the thing had been settled in for a
while, they found this error: the floating point was
computing incorrectly, although only slightly inaccurately.
PC: Oh, my God. That must have been early on. I didn't get on the LARC early
on. I think Chuck was one of the first ones on there. And
on the LARC you could make code patches in a paper
tape that you could read in at execute time.
GAM: The LARC had many brilliant ideas in it. Its major difficulty was that it was
a decimal machine, and we had learned binary by then.
PC: Yes, Well, it also had a small memory30K or something like that, and it
had drums. But we learned how to do buffered I/O.
GAM: Chuck did that marvelously well using those drums.
PC: Well, the same problem was...
GAM: Message passing?
PC: Yes, it was message passing. You had to do the same thing. You read in
something that you hadn't computed yet, you wrote out
what you had computed, and you worked on something
in between. But we don't do that any more!
GAM: Oh, more than that, I think of the quality of people that were involved
made it work very well.
PC: I think so. You know it's hard to say. If you have a more or less endless
supply of money, and people can do what they want to
do, they can do marvelous things. And they don't always
just do stuff that's useless. A lot of scientists that I know
are doing creative things. It just takes somebody with
another kind of creativity to put all of that stuff together
and make it work in a useful way for other people.
GAM: Yes, that was the idea of the Lab.
PC: Well, yes. But there were also people at the Lab who were doing just
out-and-out physics. Bernie Alder, for example, did particle
dynamics but it wasn't always tied to the Lab's
programmatic effort. Today, that is the basis for
Computational Materials Science.
He was able to do all that because he was on the Academy of Sciences; he
attracted good people or something like that. But I'm not
sure that any of the molecular dynamics models that he
and Tom were working on did anything directly for the
Lab, except to use machine time.
GAM: Well, they polished ideas in Monte Carlo techniques through those codes.
And they also polished ideas about how to do shell
computing: You don't have to search
every point, you just find a sphere that includes these
points, and then you can stay inside or outside of it, and
things like that. In fact, Norman had a great deal to do
with that, too, of the so-called neighborhood technique
that he developed for making the STEP code run fast.
PC: Yes, he had his finger in a lot of things, Norman did.
GAM: Well, that's what made him so good, you know? The story is, he gave up in
disgust in the early days, because FORTRAN wouldn't
compile the big design program then being used. So, he
sat down with the program FORTRAN deck, and he
wrote the assembly program on a keypunch!
PC: Really? You know, what I remember is that for that program, Leo
Collins was the first programmer.
GAM: Yes, I think that's true.
PC: Leo Collins was a botanist.
GAM: Oh, was he? I didn't know that!
PC: Yes, he was a botanist! I mean, we didn't know the word "programmer" in
those days, or "computer scientist"what is that? We
were all called "coders". We wrote machine code, and
then some of us learned how to do FORTRAN.
And I remember there was a parallel version that Frank
Holden was working on for the designers. But that didn't
work. Then Bill Schultz flowcharted everything. I don't
know if any of his flowcharts still exist. Now, there's a
person who should have gotten the Lawrence Award.
GAM: I quite agree! By the way, Bill's flow charts are still relevant, and some of
the originals are saved in the Lab's archives.
PC: A Lawrence award for Schultz is something that we triedBill Zagotta
worked very hard at trying to make that happen.
GAM: That's good!
PC: This was after Schultz left the Lab. Zagotta tried but it never happened.
And I think that's one of the many unfortunate things we
can blame on the administration. What they did, was to
deny Bill Schultz that honor.
GAM: He's the guy who established, by way of that design code,
big, big computations. It is also clear that his work was
the biggest justification for our getting Supercomputers.
PC: Yes, exactly. A long computation in those days was 300 hours. And I think
that's always held true, that 300 hours is about the
amount of time that a human being can devote to a
calculation. By the time 300 hours of calculation have gone by,
you've forgotten what the question was!
GAM: Just right.
PC: And that design code has evolved to the point, these days, where it can be
now less than a five-minute calculation. Machines have
changed so much. But now you get your answer to a 2D
hydro calculation in a very short period of timeabout
the time that it used to take to get a 1D result. It's really
amazing. Yes, you should interview Bill.
GAM: If I can find him! I tried once before to find him, but I couldn't.
PC: He's in Berkeley. And I'm not sure howI think he still has bad feelings
about the Lab, and so he might tend to froth at the mouth a lot.
GAM: Let him! It certainly historically true.
GAM: Well, it seems like you've reviewed your memories, so this is a good time to
stop. Pat, I want to thank you for taking the time to
reminisce about some of your early Lab experiences.
 The dd-80 was a very high-speed display system built by Data Display, Incorporated in St. Paul, MN.
 This camera was called a flight-research camera that received a pulse for each frame; it was originally designed for
spark chamber work and was adapted for use with the dd-80.
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