Hello and welcome back.
If you follow the channel, you already know that my HP 9825, famously used by Mr. Fancy Pants...
Yes, yes, we found him! The one and only Mr. Fancy Pants, whose picture I proudly showed in all the
episodes of my HP 9825 repairs. His real name is Bob Stern, and he is one seriously pedigreed
engineer. We found him thanks to a viewer who used to be his roommate and recognized him.
And if we’d known where to look, we’d have found him all over YouTube a long time ago.
As of today, he his still working for Keysight, as their Principal Metrologist Emeritus.
Impressive. Now I should have called him Mr. Fancy Title, really.
So you can find him on quite a few Keysight’s videos about
the subject, including this recent interview by the show’s current host.
But back to the famous picture. Bob was the software engineer responsible for automating the
HP 8950B, a pioneering radio test setup, featuring some of the very first HP-IB instruments.
He posed for the picture with the machine he was actually working on.
I couldn’t wait to talk to him via zoom. Bob apologizes for the big band-aid on his forehead,
as he recently had some minor skin surgery. I guess like the vintage HP equipment,
we vintage people are sometimes in need of repair now and then.
[Bob] For this call today I was just reflecting how far automation has come. When I joined the
company in August of 76, there was one hardware engineer who had designed that interface box
and there was one software engineer who had written maybe two-thirds of the code,
and then he left to go back to get a master's degree in the East coast somewhere. And so they
wanted to finish this thing. And when I was hired they said: can you program? And I said: sure!
[Marc] Well you know, first of all, the question that everybody wants to know:
is there a story about the pants?
[Bob] I tried to look up the name of the illustrator from the catalog
and I wouldn't have talked to her for 42 years, but she was pretty mad when I showed
up that way. But she said: dress nice! [Marc] You nailed it! [Bob] So, you know,
those were polyester bell bottoms, that was fashionable. I mean you can't see the shoes,
but those those were saddle shoes, highly polished, two tones!
[Marc] It looks so good that I thought they would have hired a model for the picture!
[Bob] No, HP didn't do that.
HP had indeed a tradition to take instrument pictures with HP employees and not models.
Like this one for the HP-35 calculator, where the HP-35 is clearly the star of the picture.
But in this famous one, I’m not sure that the calculator is the star of the picture anymore.
But no, she is not a model: this is Karen Cambria,
an HP engineer, with the calculator she used in her daily work.
This is another famous picture showing the HP 5451 Fourier Transform Analyzer. Same problem here,
you have to focus really hard to see a computer in the picture. The story goes that she was a
French HP employee, chosen to go with the French mathematician Joseph Fourier heritage theme.
And while we are on the fashion theme, there are of course other fancy pants appearances,
like this one in the 1979 catalog - and no, we confirmed this is not Bob: he would have given
the HP-IB class rather than taken it. And here is DEC’s version of fancy pants computer engineering.
But Bob is a true engineer, and what he really wanted to talk about is what the
system actually was, and how he remembered using the then brand new HP 9825 and the HP-IB bus.
[Bob] I can tell you a little bit about that system
and how it fit in at the time if you'd like. Well when I came out of college,
my first job was with the Stanford Park division of HP in 1976, and
at that time they had just invented the HP Interface Bus, so-called HP-IB. A lot of people
later called it [IEEE] 488, but that was only when HP gave it away. But it was the HP Interface Bus.
And looking at... Let's see. I'm looking at that
at the top, would have been a [HP] 62-something or other power supply.
[Marc] Yeah I have it actually.
[Bob] Next one down is an [HP] 5328
counter yes and then that would have been probably an [HP] 3455 voltmeter, I'm thinking.
[Marc] Yeah I have that too, yes, the black, they made a black version of it, that's correct.
Oh, this sure is one of my favorite voltmeters. I’m sure you spied it on many videos,
like this one testing the repaired Alto power supply, or if you follow on Patreon,
showing off its microvolts digits while measuring a newly restored HP precision supply.
[Bob] The next one down was a custom interface that had switching, so that you could connect to
whatever you needed to connect to for the source. And it also had a switchable notch filter, because
in those days, the most important measurement of any radio was for receiver with sensitivity. And
sensitivity is the minimum RF signal with appropriate modulation which results in
intelligible speech. And nowadays of course that would be a Bit Error Rate. But in those days,
it was signal plus noise and distortion over noise and distortion. They called it SINAD for short.
You would switch in a notch filter and switch it out, you take two voltmeter readings,
take 20 log of that, and that was your reading. And the requirement was,
you were looking for the signal level that would produce 12 dB SINAD ratio.
So going in the system, the one below the shelf, and that was probably some Motorola radio.
I'm guessing, you know, a narrowband radio.
[Marc] Actually while reviewing the footage with Bob, he meant to say the radio ON the shelf is a
Motorola radio, but the instrument UNDER the shelf is the famous HP 8660A synthesizer,
at the time the king of all signal generators, going from 10 kHz all the way to 2.6 GHz.
[Bob] Just below the shelf was a 3320 synthesizer. [Marc] This one
here? [Bob] Yeah, and that was used to generate one kilohertz. It was a 20 Megahertz generator,
but it was used to generate 1kilohertz or 400 hertz tones, of different levels.
[Marc] So you get it, right? This signal generator is used to modulate the RF signal generator,
and the combo makes a calibrated, entirely programmable reference transmitter signal
with which you test your radio receiver.
[Bob] And let's see... [Marc] That one is hard to see. [Bob] I have to look and remember.
[Marc]That might be a pulser? No it would have - this is one of the HP-IB boxes. [Bob] That
is the switch controller. Darn it, I can't remember the number right now. [Marc]
I can look it up [Bob] But that's what is actually controlling the interface
box that's above. [Marc] This one, those two are connected. [Bob] Right, right. [Marc] So you get
HP-IB to that and then it controls this. [Bob] Yeah, right, because the interface
didn't speak HP-IB. And the bottom is a 436 power meter. [Marc] Okay, yeah.
At the time that we did this system there were only 12 or maybe 13 instruments that had HP-IB,
period. That was it, that's all there was. And this system had, depending on the option you
picked, 10 or 11 of those. So I was, at the time, I was kind of the programming expert. And somebody
came through one day from the field and saw what I was doing and I said holy sh*t! And then the
next thing I knew, we took 12 of our sharpest field people that were customer engineers,
and they became - uh let me think - I think they were called HP-IB specialists. And so they their
job was to help people program. You know, if somebody wanted to buy an instrument to,
you know, make some measurements in their laboratory, they knew it could be done but
they didn't know how to go about doing it. And these HP-IB specialists would show them how.
So interestingly, I actually gave a class to all 12 of the first
people. Of course, then HP-IB got huge after that.
A couple of the coolest things about the 9825 is, in those days,
everything was compiled. So you'd write a program, you'd have to use an [IBM] model 26 keypunch,
then you'd try to compile it, and you'd see if you got any errors. And if you didn't, then you
could run it. That was FORTRAN. Well, a cool thing about something like HPL, is that all you had to
do at the end of the instruction, is hit the store key. And if it was okay, it took it, and it wasn't
it didn't. [Marc] Yeah, interpreted language. And it's so easy and natural to program HP-IB,
it's a one liner, right? You don't have to install any drivers, anything, no discovery, no nothing,
right, you just "send to this instrument, that string" and off it goes. [Bob] That interface,
that HP-IB interface was magic. And that turned the 9825 into an instrument controller.
I mean it was magical after that, because prior to that,
automation was really hard to do, really expensive, and always terribly custom.
A year or two ago, when I was walking through one of the labs in Santa Rosa, there was one
of the young engineers and there was a leftover, there was a just an old HP-IB cable sitting there.
And he said: "oh, this is useless" and he was gonna throw it in the bin.
And I said: wow no respect! You know, he's used to LANs and everything else.
I had an interesting thought that you might get a kick out of. So yesterday I swapped out my
30 year old irrigation controller and put in a new one which has WiFi control.
I was just thinking how far everything has come. It used to be, you could only do it with HP-IB,
and you know this and that. Now on your phone, you get pictures of the different zones,
and you have all this - you know it's just another app. You just answer questions on screen and
next thing you know you've got it. I was quite impressed with the application.
You know, what I really enjoyed about that system was, you know, customers would give us a
radio or a two-way radio, and they'd say: can it test this?
And in a couple of days I'd take my last demo program, and put a new one in. And I probably,
just like anything, you'd spend about 80 percent of your time formatting the output.
The program was done in probably 10 minutes. And they would give that to the customer
and then they almost always said: is it okay if we use this in our production line?
And of course my boss would say: yes of course. So there were a lot of radios that had application
programs that were way under 300 lines on the 9825 that got tested in those days. And
we would crank those out and give them to people. And it was a really fun time for automation.
[Marc] So you went through the whole HP-Agilent-Keysight transition?
Right. Yeah, I mean, if I'm talking to somebody,
I still know most of the model numbers going all the way back. And
if a customer says HP, I don't correct them. And if I say HP, they don't correct me either.
I went to a calibration conference one time and the gentleman who would probably have
been considered the principal engineer at the time - I don't remember what happened,
but they they basically pushed him out, they asked him to retire, because they were trying
to trim. And on his way out, he said: if somebody doesn't get into these standards committees,
they're going to still make standards and we're going to have to do them, and if we
didn't participate we're going to be sorry. So I wrote a note to the managers, because I thought,
well, he's right! And I kind of knew what would happen. And they said, okay, you're right,
why don't you do that. So I didn't really intend to get into that, but I'm pretty sure that's
one of the reasons why I was able to continue working without getting let go from 2000 to 2010.
[Marc] Okay, well, on that one, thanks a lot. [Bob] All right,
nice chatting. [Marc] We'll be in touch. [Bob] All right, it was very pleasant to talk to you Marc.
[Marc] Same here, thank you very much! [Bob] Bye then! [Marc] Bye!