I was heading to write about asynchronous circuits, and in the shower this morning I got to wondering if we even had the “right math” to talk about meaningful and useful things when it came to circuitry that is inherently asynchronous. We’ve been locked into this clockworks lock-step digital stuff for quite a while, and there really was a few other choices if you take the computing field back far enough.
So I had this professor – as I recall he was never anything higher than an associate professor – name Ed Vredenburg. I can’t find a single link on the web about him – but man, he made an impression. 20 years ago, he taught myself (and a pile of other EE students) basic circuits with Dr. Leavene (Dr. Leavene was also known as “Dr Death” – although I never perceived his as such – but that’s another story.)
Anyway, Vredenburg was this gruff, smoking, kind of nasty old fellow who’s office was a 6×9 cinderblock firetrap. I don’t recall if he died shortly after 1986, but I do recall he wasn’t around by the time I graduated in 1990. To be honest, I’m not even sure I’m spelling his name right. But at the time, he was all practical and very “EE” focused – on all those things that actually rather bore the crap out of me – power engineering, transmission, etc. But for all this time, I do recall him being somewhat put off by the lockstep digital age, and I wonder now in retrospect if he didn’t have a lot more knowledge that he never could get out to anyone else. I specifically recall some disgruntled lectures/conversations in labs where he was likening your standard transistor circuits to integrators and mathematic calculations, and how he said “any of that math you come up with from calculus, you can devise a circuit to do”.
At the time, I thought “Well, that’s just all and goody, but what the hell good use is that? I’d spend 6 hours putting together these circuits when I could spend 30 minutes on paper (and maybe a calculator) and solve the problem”. Digital seemed just fine to me. I think that master of the OpAmp (which meant more to me as a means of getting a decent radio amplifier working) may have actually been a fan of the analog computer. Although it’s taken as a sidenote of potential historical interest, I wonder if we didn’t miss something crucial back there. There’s still potential thought to that, although little has hit the news recently. An article in the EE Times from 1998 is the most recent I could quickly spot.
But back to Ed – when I was looking for a link, I went to MU and looked through this faculty pages. I was a tad shocked to see all my professors in the Emeritus list these days – with a few exceptions. There’s no link to my favorite professor – Hugh Graham. Heh – he dressed a bit like a biker, there was a rumor he’d ridden a motorcycle in to his office (and the 3rd floor of the EE building), and he was a seriously smart, no-nonsense guy that knew digital computer layout extremely thoroughly. His class on VLSI design stuck with me for years. In fact, I still have the book. Other professors I didn’t care so much about – the Charlson’s held the majority of the political power, pulling in grants for semiconuctor research into gallium-arsenide chips and I always rather though of Elaine Charlseon as rather snooty and bitchy. My advisor, Dr. Deavany is still active faculty aparently. He spent most of his time way in his head – so much so that I remember watching him run into a tree (nice black eye from that!) while walking across the quad thinking about something. The world around him just didn’t really impact him, well – until it really impacted with him.
Well, enough opinions and rumors about retired MU faculty.
I’m of the opinion that I don’t have the right language, or the right “way to think” about these asynchronous circuits, and that the cycles that can happen – the feedback loops and chaotic potential – are really somehow quite critical to use performing some of these more analoge tasks better. Image recognition, voice recognition – it’s all analog stuff. The ‘pedia has some interesting backgrounding around the analog computer, but I think the important bit isn’t the specific application of any one thing, but the “how to think and talk about it”. I don’t know – maybe it’s out there, and I just haven’t heard about it or didn’t grok it when I was exposed to it.
Update: I found a link to Ed Vredenburg. Tenuous, but there. His full name was Edward J Vredenburg – and the only link I found was in the Columbia Missourian archives – he was a pall bearer in a 1967 funeral of Roger Kyllonen. And the worst is that archive doesn’t include 1986 through 1992 – pretty much my time at MU. Maybe sometime…
One thought on “Edward J. Vredenburg”
I guess you’re right about this analog thing. DSP is used because it can be mathematicaly modeled very easily and give any kind of output. Analog on the other hand is difficult and rarely perform exacly as designed.
Sadly it’s not about what’s better — it’s about what we can do in mass production with little failure rate. And probably 10.000 transistors are way cheaper than a single 5% capacitor. (the standard ones are 20% and even 5% is a big error that degrades the signal)
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