Flutterby™! : Analog or Digital Computer - Are they really the same? 2008-04-29 14:23:02.178791+00

Analog or Digital Computer - Are they really the same?

2008-04-29 14:23:02.178791+00 by ziffle 8 comments

I remember pausing before I starting looking at my first desk top computer and asked myself - If I was to design a computer how would I do it? I never really answered that but I have to say I was a little dissappointed once I realized what a digital computer really was. Two states, off or on. Now we make them go faster and faster but you know its really not awe inspiring how its designed.

I read 'Chaos Theory' and he used an analog computer he found in the basement of UCLA (?) to do testing. I always wondered how it worked and was it any more inspiring than digital.

Analog Computers

Add to this my disappointment when I first heard CD music and how it leaves out all those notes and I am not really enamored by All Things Digital

#Comment Re: analog computers made: 2008-04-29 15:59:26.458124+00 by: andylyke

I was in school at the dawning of the digital age, so we still used analog computers for a lot of stuff. They're really quite elegant, and I'd love to get my hands on one of those old Princeton desktops that had a dozen or so op amps, a few dozen ten turn pots, caps, ... and really taught us about control systems. In fact, I'm off to Craig's List and EBay now. Thanks for reviving the memory!!!

A friend of mine tickled the ivories back in the '70s, and is now trying to get his fingers back into shape. He's mostly concentrating on piano, which is distinct from keyboards in that digital pianos try very hard to mimic the physical reaction of keys pushing levers pushing hammers, but he's also got a soft spot for some of the analog synthesizers he played back in the days.

So he's got a room full of various different electronic pianos and synthesizers.

One of the things that amazes me is how much effort goes into recreating the "imperfect" behavior of the analog world, whether that's attempting to make keys respond differently depending on which weight hammer they would have been moving had this been on a device built a hundred years ago, or whether that's how the temperature affects the virtual capacitors that are controlling the decay time of some oscillator that's now being made in software.

Of course on the other side I'm starting to look at circuits where the digital modeling isn't cheaper than doing it in analog in the first place.

The thing to remember, however, is that what makes digital so appealing is that it's far easier to make it deterministic. Quantifiable inputs with known granularity make for repeatable outputs.

#Comment Re: correction made: 2008-04-29 16:08:02.203637+00 by: andylyke

You sent me off on a search, and I need to correct my earlier nomenclature. Electronic Associates of Princeton, NJ made the computer I loved so much.

Dan: The efforts in recreating the analog in digital are usually focused on the human-machine interface. One of the things that was lost in Modernity was that our bodies exist in a purely analog world. Analog interfaces "feel" better because we can actually feel them. We can't feel a 0 or a 1. Our bodies anticipate the infinite range of values between 0 and 1. As ziffle implied, the CD feels unnatural because the analog has been reduced to 0s and 1s. Sure, the idea is that the 0s and 1s stream past faster than we can perceive - but our perception is analog as well. It's not that hard to notice the expectation of fills between samples - and it's why people like to put lots of analog filters on the digital signal. Of course, the speaker is the best filter - it exists in our analog world and can only produce analog sound...

"Quantifiable inputs with known granularity make for repeatable outputs. " This is what makes flutterby well - special because we know in his heart he's really not talking about computers but some girl we have not met yet.

Andy: Those computers look more like 'computers' than the new ones. They are so beautiful but since we discovered girls we now realize we can not put them in the living room where they should really be displayed. The compromises we make.

Clearly all girls are not created equal. I would love to have one of those beasts in my living room.

and when I read Dianne's comments I stuck an 'R' into the word beasts - so I am truly an analog. And those should be displayed in the living room, Andy.