Speaker 1: Welcome to text Stuff, a production from I Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host,
Speaker 1: Jonathan Strickland. I'm an executive producer with I Heart Radio
Speaker 1: and I love all things tech. And when I was
Speaker 1: growing up, we had a couple of computers at my house.
Speaker 1: One was an Apple to E that was our our
Speaker 1: first real personal computer, and the other, which came later,
Speaker 1: was an IBM Compatible. And at that point, I think
Speaker 1: I was almost a teenager or maybe a young teenager
Speaker 1: when we got the IBM Compatible. I don't remember exactly
Speaker 1: when my dad got our first modem, or whether it
Speaker 1: was on the Apple to E or on the two
Speaker 1: eight six IBM Compatible or one of the later ones,
Speaker 1: because we got a three eight six from there. But
Speaker 1: one thing I do remember really well was a particular sound.
Speaker 1: Any of you guys out there around my age or
Speaker 1: so we'll remember that noise too. Some of you younger
Speaker 1: folks might have heard it before, and a few of
Speaker 1: you might still use one. I mean, they're not obsolete,
Speaker 1: but they are the exception rather than the rule. And
Speaker 1: to the rest of you that probably sounds entirely foreign,
Speaker 1: and it is the sound of a dial up modem
Speaker 1: making a connection. So in today's episode, I'm going to
Speaker 1: talk about modems, specifically dial up ones. Before I launch
Speaker 1: into my trademarked history section, let's talk about what a
Speaker 1: modem actually does. A modem's purpose is to facilitate communication
Speaker 1: between computers, and the word modem is a portmanteau, which
Speaker 1: means I get to revel in my background in English lit. So,
Speaker 1: a portmanteau is a word that combines both the meaning
Speaker 1: and the sounds of two or more other words, and
Speaker 1: typically we do this to convey a particular concept or meaning. So,
Speaker 1: for example, brunch, something I miss dearly during this time
Speaker 1: of isolation, is a portmanteau. It combines the sounds from
Speaker 1: the words breakfast and lunch, and it also combines the
Speaker 1: meaning of those two words. Brunches a meal that occurs
Speaker 1: later than breakfast but earlier than lunch, and typically the
Speaker 1: menu for brunch includes foods that you might encounter at
Speaker 1: either of those other meals. So what words and ideas
Speaker 1: combine to form the word modem, Well, that would be
Speaker 1: modulation and demodulation. I'll explain that a little bit later
Speaker 1: in this episode, but first let's dive into some history
Speaker 1: to understand the genesis of modems for computers. It actually
Speaker 1: helps for us to go even further back to talk
Speaker 1: about the telegraph, which I know sounds crazy, but hear
Speaker 1: me out way back in the mid nineteen century. So
Speaker 1: the mid eighteen hundreds, inventors, including the famous Samuel Morse,
Speaker 1: we're developing a method of communication that depended upon sending
Speaker 1: electric signals over wires, and it was ingenious in its simplicity.
Speaker 1: So on one end, you've got a switch. If you
Speaker 1: close the switch, you let current pass through a circuit
Speaker 1: into a wire. If you open a switch, you cut
Speaker 1: off that path. The current cannot flow through. Now, this
Speaker 1: particular switch was spring loaded. If you pushed down on
Speaker 1: a little button, you closed the switch. If you let
Speaker 1: off pressure, if you took your hand the way, it
Speaker 1: would spring back into the open position. So it was
Speaker 1: only closed if you held it closed. On the opposite
Speaker 1: side of that wire was the receiver, and the receiver
Speaker 1: had an electro magnet in it, so when current flowed
Speaker 1: to the electro magnet, it would generate a magnetic field.
Speaker 1: That's all electro magnets were, right. The current flows through,
Speaker 1: it generates a magnetic field. This magnetic field would then
Speaker 1: pull down a ferromagnetic lever, And so if you hold
Speaker 1: down the switch on the sending end, the lever on
Speaker 1: the receiving end would stay down because the electromagnetic force
Speaker 1: would continue to pull on it. If you let go
Speaker 1: of the switch, the lever on the opposite side would
Speaker 1: pop back up once that electro magnetic attraction stopped. You
Speaker 1: can also have it just be some sort of buzzer
Speaker 1: or alarm. So you hold down the switch and it
Speaker 1: makes an electro magnet sound, a bell or a buzzer.
Speaker 1: Now that by itself is not terribly useful, but one
Speaker 1: thing you could do is establish a pattern and determine
Speaker 1: what meaning there is in the pattern. So, for example,
Speaker 1: if you were to hold down the switch for a
Speaker 1: little bit, that might be a dash. If you just
Speaker 1: tapped the switch, you would get a dot. And then
Speaker 1: by establishing what dots and dashes mean, you could build
Speaker 1: out a code. That's exactly what Morse did. He developed
Speaker 1: his eponymous code, the Morse Code, to encode characters into
Speaker 1: collections of dots and dashes. You could take a message
Speaker 1: written in a language like English. You convert every letter
Speaker 1: in that message into its respective dots and dashes. You
Speaker 1: send it off by telegraph by tapping this message out
Speaker 1: on the sending end, and an operator on the receiving
Speaker 1: end would listen to those taps, knowing whether it's a
Speaker 1: dot or a dash. They would take down the message
Speaker 1: and to code it back into its original language. You know,
Speaker 1: if they were really good, they could do it letter
Speaker 1: by letter. Otherwise they were actually writing down dots and dashes.
Speaker 1: A little bit later, you had engineers who created a
Speaker 1: version where the receiving end had a lever where it
Speaker 1: ended with a little wheel that was coded in ink,
Speaker 1: and there was paper tape that would constantly move at
Speaker 1: a speed built neath the lever. So when the sender
Speaker 1: pressed the sending key down, the receiving key would come
Speaker 1: down and that wheel would make contact with the paper.
Speaker 1: And then based upon the length of the switch press,
Speaker 1: you would get a physical dot or dash. You would
Speaker 1: actually get a printed version of the coded message which
Speaker 1: you could then decode. Then thus you would say the
Speaker 1: transcription step where someone would have to take down the
Speaker 1: dots and dashes by hand. Now trust me, this is
Speaker 1: all going to lead into modems, but we do have
Speaker 1: a couple of other stops. We have to make first.
Speaker 1: There was a lot of work in the field of
Speaker 1: teleprint ters in the nineteenth century, including stuff like stock
Speaker 1: tickers that would take in an electric signal and then
Speaker 1: print out results based on that. But we're gonna jump
Speaker 1: over all of that for right now to get to
Speaker 1: the early twentieth century. In nineteen o two, an electrical
Speaker 1: engineer named Frank Peern was experimenting with a method to
Speaker 1: create a printing telegraph system that would let people send
Speaker 1: and receive text messages, essentially using typewriter like devices that
Speaker 1: would connect to each other via wires. You could have
Speaker 1: dedicated wires between two of these things, or you could
Speaker 1: have them tap into some other wired system. He encountered
Speaker 1: some challenges along the way, and after a few years
Speaker 1: of frustration, Peern decided he's going to piece out of
Speaker 1: this whole endeavor. But then his work was carried on
Speaker 1: by another engineer named Charles Crumb. The goal was again
Speaker 1: to make an automated system that could receive incoming messages
Speaker 1: and print them in alpha numeric characters on paper, so
Speaker 1: instead of getting those dots and dashes, you would get
Speaker 1: the original message. As it was intended, it was skipping
Speaker 1: the whole encoding decoding step. You wouldn't have to put
Speaker 1: a message into morse code and then decode it. At
Speaker 1: least it was skipping in as far as the human
Speaker 1: operators were concerned. It was taking all of those sort
Speaker 1: of intermediate steps required by traditional telegraphy and automating them.
Speaker 1: But how well, it comes back to the idea of
Speaker 1: using electric pulses to indicate a letter, So it really
Speaker 1: comes back to that closed and open switch description. The
Speaker 1: engineers coded each character as a series of five potential
Speaker 1: electric pulse states, and the states were either on meaning
Speaker 1: current was flowing through the circuit at that instant, or
Speaker 1: off meaning no current was flowing. And they represented each
Speaker 1: letter as a sequence of either on or off, and
Speaker 1: that's sequence would include five pulses. They referred to the
Speaker 1: on current state as marking and the off current state
Speaker 1: as spacing. So the letter D, for example, would code
Speaker 1: into mark space space mark space, meaning the current would
Speaker 1: be on, off, off, on off as its sequence of
Speaker 1: five pulses. The receiving machine would interpret the incoming signals
Speaker 1: as letters. It would say, all right, we're looking at
Speaker 1: this span of time and we see that the current
Speaker 1: is on off, off, on, off. That's the letter D.
Speaker 1: The code itself dated all the way back in the
Speaker 1: eighteen seventies. It was invented by Emil Baudoux Bado that's
Speaker 1: b a U d O. T made numerous contributions to
Speaker 1: the field, including a method of multiplexing, that is, being
Speaker 1: able to send multiple messages simultaneously through a careful system
Speaker 1: of clockwork switches so that the correct information would go
Speaker 1: to the correct teleprinter. His work was important enough that
Speaker 1: we take his name Baudo, and we created the unit
Speaker 1: for data transmission with modems, the baud b a U D.
Speaker 1: More on that in just a moment. But this approach
Speaker 1: required one other very important component. The sending and receiving
Speaker 1: machines had to be quote in step, meaning they had
Speaker 1: to be synchronized with each other. If they weren't, then
Speaker 1: the receiving machine might start interpreting signals out of step,
Speaker 1: out of sync with the sending machine, and thus print
Speaker 1: the wrong letters. Because remember every character coded into a
Speaker 1: signal of five pulses. If the receiving machine is off
Speaker 1: by even one pulse, it's going to misinterpret what's being
Speaker 1: sent to it. So if you were sending a message
Speaker 1: that was five letters long. Those five letters would be
Speaker 1: represented by twenty five short pulses, five pulses each, and
Speaker 1: the first letter would be pulses one through five, the
Speaker 1: second letter would be pulses six through ten, and so on.
Speaker 1: But let's say the receiving machine only starts to pick
Speaker 1: up at pulse three. It misses the first two pulses.
Speaker 1: It thinks pulse three is actually pulse one, which means
Speaker 1: it's going to use the pulses three through seven to
Speaker 1: be the first letter, and the pulses eight through twelve
Speaker 1: will be the second letter, and so on, with the
Speaker 1: final letter having two spaces at the end because no
Speaker 1: more signal is being sent. While the engineers were able
Speaker 1: to create a way to send and receive signals, it
Speaker 1: was this synchronization stuff that would be a really big challenge.
Speaker 1: They had to make sure that both machines knew quote
Speaker 1: unquote when messages were coming through, so that any errors
Speaker 1: that were detected would be known and it wouldn't just
Speaker 1: print gibberish. The solution turned out to be fairly elegant.
Speaker 1: Howard Crumb, the son of Charles Crumb, proposed that every
Speaker 1: code combination representing a letter would first be preceded by
Speaker 1: a start pulse and followed by a stop pulse. So
Speaker 1: every single letter would have a special pulse at the
Speaker 1: very beginning and the very end of that sequence of
Speaker 1: five to indicate this is the beginning of a letter,
Speaker 1: this is the end of a letter, ignore anything else.
Speaker 1: That way, the receiving machine would detect the true beginning
Speaker 1: and the true end of each combination, and would more
Speaker 1: likely print the appropriate letter. It was a simple way
Speaker 1: to achieve full synchronization, though there was still no error
Speaker 1: correction at this point. Now I'll have to dedicate a
Speaker 1: full episode to teletype and the advancements that made it possible,
Speaker 1: because there's a whole lot more than that brief overview
Speaker 1: I just gave. But what does this all have to
Speaker 1: do with modems. Well, the process of encoding information and
Speaker 1: sending it through a signal is modulation. The process us
Speaker 1: of receiving a signal and decoding that to get at
Speaker 1: the original information is demodulation. The same process is used
Speaker 1: in lots of other technologies like radio. With radio signals,
Speaker 1: you take a carrier wave, that is a radio wave
Speaker 1: with a consistent amplitude and a consistent frequency. It would
Speaker 1: just be a pure tone if you could hear it,
Speaker 1: if it were in the range of human hearing. So
Speaker 1: you get this pure radio wave. Now you encode information
Speaker 1: by laying on another wave, by altering that wave in
Speaker 1: some way, you can change the amplitude. If you do
Speaker 1: it through those changes, you get what is amplitude modulation
Speaker 1: or a M radio. Or you can change the frequency
Speaker 1: and you get frequency modulation or FM radio. The receiver
Speaker 1: on the other end follows the same process in reverse.
Speaker 1: It takes these waves in and then converts them back
Speaker 1: into the original information that was sent out, like you know,
Speaker 1: your your pop radio station or whatever it is you're
Speaker 1: listening to. So really this is all about creating a
Speaker 1: reversible process that lets you translate information into some other
Speaker 1: format and then back again on the other side. Now,
Speaker 1: in the nineteen twenties, countries around the world slowly began
Speaker 1: building out telephone infrastructure, and there was now the opportunity
Speaker 1: to piggyback the infant teletype technology onto the phone infrastructure,
Speaker 1: except for the fact that phone companies were pretty dead
Speaker 1: set against it. Previously, these machines relied upon purpose built wires,
Speaker 1: but that limits their use right, and you can only
Speaker 1: send messages to whichever machines are hardwired to your machine.
Speaker 1: That doesn't really give you a whole lot of options.
Speaker 1: What if you wanted to send it to somebody else
Speaker 1: whose machine wasn't directly connected to yours, You'd be stuck.
Speaker 1: The telephone network would allow for a lot more connectivity
Speaker 1: and had a lot more infrastructure that was already established.
Speaker 1: One early approach was to use non switched telephone lines
Speaker 1: that were dedicated for the sorts of connections. These are
Speaker 1: called least lines because these lines were meant only for
Speaker 1: that kind of process and would not be used for
Speaker 1: phone to phone conversations. But that was really expensive. It
Speaker 1: would be way more cost effective and more useful to
Speaker 1: tap into the general telephone network, but there needed to
Speaker 1: be a couple of things for that to happen. One,
Speaker 1: you had to get it past the telephone company, which
Speaker 1: essentially in the United States was a T and T,
Speaker 1: and another one you had to find a way to
Speaker 1: modulate and demodulate the information so it could transmit over
Speaker 1: phone lines. There had to be a way to have
Speaker 1: two teletype machines establish a connection with one another and
Speaker 1: transmit and receive messages. At the time the phone infrastructure
Speaker 1: in the United States was capable of carrying sound frequencies
Speaker 1: between three hurts and three killer hurts, also known as
Speaker 1: the voice band. Now, that's a pretty narrow range of frequencies,
Speaker 1: and you could think of frequencies as being related to pitch.
Speaker 1: Lower frequent sees have a lower pitch. Higher frequencies have
Speaker 1: a higher pitch. But the range of human hearing goes
Speaker 1: from twenty hurts to twenty killer hurts, So the voice
Speaker 1: band represents only a small slice of the full range
Speaker 1: of human hearing. It also means that any solution that
Speaker 1: would convert information into audio to transmit over phone lines
Speaker 1: would have to work within those limitations. Oh and here's
Speaker 1: another fun fact. We call this system the plain old
Speaker 1: telephone service or POTS. Now it's been updated since then,
Speaker 1: but it took a long time for that to happen.
Speaker 1: The United States was relying on POTS until the late
Speaker 1: nineteen eighties, so it was a venerable technology by the
Speaker 1: time we finally got off of that. The teletype example
Speaker 1: is also important not just because of modulation demodulation, but
Speaker 1: because it would help inform future engineers as they began
Speaker 1: to think about creating methods for computer systems to communicate
Speaker 1: with one another. Keep in mind that the early computer
Speaker 1: systems were all independent. They were mainframe systems that performed
Speaker 1: like an isolated island. You needed physical access to the
Speaker 1: machines or two dumb terminals that were connected to those
Speaker 1: machines in order to make any use of them. Communication
Speaker 1: with other computers wasn't really a possibility for numerous reasons.
Speaker 1: One was that different computers effectively spoke different languages, so
Speaker 1: a program written for one type of computer would not
Speaker 1: work on another, just as a program written for a
Speaker 1: Mac computer won't run natively on a Windows based machine.
Speaker 1: But another reason was just that there was no interface
Speaker 1: through which computers could send or receive information with one another.
Speaker 1: When we come back, we'll talk about how that would
Speaker 1: begin to change, But first let's take a quick break.
Speaker 1: The development of modems, which weren't yet called modems, or
Speaker 1: were they actually for computers just yet, would coincide with
Speaker 1: other trends in technology. Now. As we've learned in many episodes,
Speaker 1: the development of tech rarely follows a straight timeline where
Speaker 1: event A leads to event B, which leads to events see.
Speaker 1: Usually you're actually talking about multiple timelines of multiple technologies
Speaker 1: and they ultimately either converge or at least cross paths,
Speaker 1: so it makes it complicated to tell the history. So
Speaker 1: while companies were working with teleprinters and teletype machines as
Speaker 1: well as fax machines, which are somewhat related, other engineers
Speaker 1: were working on building out computer systems. World War Two
Speaker 1: demonstrated how computer systems could be really important. In addition,
Speaker 1: the British developed radar technology, and it was obvious that
Speaker 1: being able to share radar information quickly across great distances
Speaker 1: like coast to coast in the United States, would be advantageous.
Speaker 1: It would be really useful if a radar station and
Speaker 1: say Hawaii, could send information back to the mainland in
Speaker 1: real time. That all that stuff could be monitored from
Speaker 1: a centralized location. Now here's a big challenge. Ever since
Speaker 1: Aniak hit the scene in the nineteen forties, computers have
Speaker 1: primarily fallen into the digital category, and digital information is
Speaker 1: different from the way information would transmit over phone lines.
Speaker 1: This leads us to talk about the difference between digital
Speaker 1: and analog. This is incredibly important for modems. So we
Speaker 1: can think of the analog world as being the world
Speaker 1: of infinite variability. Everything is infinitely variable. You can change
Speaker 1: something like the brightness of a light to an infinite
Speaker 1: degree of variability. You can always go a little less bright,
Speaker 1: or maybe a little more bright, or maybe half as
Speaker 1: bright as you just went the last time, or half
Speaker 1: as dim. You can keep dividing that up into finer
Speaker 1: and finer adjustments with no limitations. If we took the
Speaker 1: number ten and we cut it in half, we would
Speaker 1: have five. If we cut in half again, we have
Speaker 1: two point five, and we can keep cutting that in
Speaker 1: half forever. We can do that until we're just exhausted.
Speaker 1: So an analog recording is one that captures all the
Speaker 1: variations in a continuous signal. The digital world doesn't do that.
Speaker 1: A digital signal deals with discreete It deals with the finite.
Speaker 1: Computer's capabilities will determine how many values any given signal
Speaker 1: can possess. The more powerful the computer, the more values
Speaker 1: it can handle. With enough values, the signal can seem
Speaker 1: to be almost like an analog one, because you've got
Speaker 1: enough information to describe that signal that upon casual glance
Speaker 1: or even careful examination, it looks the same as an
Speaker 1: analog signal. But this requires an awful lot of information
Speaker 1: to accomplish. One way to think about this is to
Speaker 1: consider a film photograph versus a digital photograph. Film is analog.
Speaker 1: Digital photography is well, I mean it's in the name, right,
Speaker 1: it's digital. So we've all heard about megapixels, right. Megapixels
Speaker 1: referred to a camera's ability to compose an image with
Speaker 1: a certain number of points of color or light, and
Speaker 1: it's all about a camera's resolution. If we had a
Speaker 1: camera with a really low resolution, I mean, like ludicrously low,
Speaker 1: let's say eight by eight pixels, that would mean that
Speaker 1: the images would consist of eight blocks across an eight
Speaker 1: blocks tall, which means that the entire image would consist
Speaker 1: of just sixty four blocks. That would be a really
Speaker 1: blocky image. It would be hard to even know what
Speaker 1: you were looking at unless it was a super simple shape.
Speaker 1: If you increase the resolution, that means you're decreasing the
Speaker 1: size of those pixels. You're decreasing the size of those blocks,
Speaker 1: and you're cramming more of them into there so that
Speaker 1: you can represent the image with more blocks, smaller blocks,
Speaker 1: creating a smoother, less blocky image. If you keep doing that,
Speaker 1: eventually you get to a resolution that's high enough that
Speaker 1: our human eyes can't really pick up on the pixel
Speaker 1: blocks at all, and to us it just looks like
Speaker 1: a photograph on film. But again, it takes a lot
Speaker 1: of information to get to that point. Here's another challenge.
Speaker 1: How do you take the information a computer deals with,
Speaker 1: which is in digital binary format, these discrete packets of information,
Speaker 1: and then how do you send that out over a
Speaker 1: phone line which carries an analog signal over physical copper wire.
Speaker 1: You have to create a way to translate the information
Speaker 1: from digital into analog. You have to modulate the computer
Speaker 1: data so it can pass over onto an analog transmission system.
Speaker 1: Then on the other end, on the receiving end, you
Speaker 1: need a device that can accept this incoming analog transmission
Speaker 1: and demodulated translating it back into binary information for the
Speaker 1: receiving computer to process. This is true for tons of
Speaker 1: different input and output scenarios, not just computers communicating across
Speaker 1: phone lines. Anytime you're using a computer system or you know,
Speaker 1: a digital system to record or analyze stuff out in
Speaker 1: the world, you're typically relying on a digital process to
Speaker 1: measure an analog phenomenon. Same is true if you were using,
Speaker 1: say an analog joystick to play a video game. The
Speaker 1: analog controls, which might include a potentiometer that tells the
Speaker 1: device how far you're pushing the joystick in any given direction.
Speaker 1: That has to be converted into digital information for the
Speaker 1: computer to do anything useful with it. But let's get
Speaker 1: back to modems, particularly so the way a modem actually
Speaker 1: modulates data starts with a carrier wave, just like with
Speaker 1: the radio. Now, you could technically communicate in a very
Speaker 1: basic way just by either turning the wave on or off. Right,
Speaker 1: you could say, all right, well, when it's on, that's
Speaker 1: a one, and it's off it's a zero. But that's
Speaker 1: not necessarily the best option. Another way is to alter
Speaker 1: the carrier wave in some fashion. You can tweak the
Speaker 1: amplitude or the frequency, just like with a M or
Speaker 1: FM radio. So modems take a basic carrier wave function
Speaker 1: and then alter it in some predetermined way to communicate
Speaker 1: digital data. The receiver on the other side gets this
Speaker 1: carrier wave with alterations, and it understands the whole process
Speaker 1: that was made to encode that information, so it just
Speaker 1: reverses it. It decodes the information and gets those delicious
Speaker 1: zeros and ones at the heart of everything. The speed
Speaker 1: at which a modem can transmit information is measured in
Speaker 1: bits per second. A bit, remember, is one unit of
Speaker 1: binary information, so it's either a zero or a one,
Speaker 1: and the unit we used to measure modem speed is
Speaker 1: the baud be a u D named after a meal
Speaker 1: bodo bad refers to a symbol rate, and really that
Speaker 1: means how many times a transmission signal changes every second.
Speaker 1: More changes per second indicate more data carried by that
Speaker 1: signal per second. Now, typically we think of this as
Speaker 1: a faster transmission speed because it reduces the time it
Speaker 1: takes to transmit any given file, but really what it
Speaker 1: means is we're able to send more data at a time.
Speaker 1: One BOD is the equivalent of one bit per second. Now,
Speaker 1: I wish I could tell you the name of the
Speaker 1: person or persons who first created computer modems, but that
Speaker 1: information is lost. And honestly, there was so much work
Speaker 1: in this area across so many different people in different organizations,
Speaker 1: all of whom made contributions that I really cannot do that.
Speaker 1: They were all in different parts of the world, they're
Speaker 1: all working towards a similar goal. I can tell you
Speaker 1: that the first commercially available modem came out of a
Speaker 1: T and t. The company, through its R and D branch,
Speaker 1: Bell Labs, was working with the North American Air Defense
Speaker 1: COME and also known as nora AD. Nora AD had
Speaker 1: a computer system called the Semi Automatic Ground Environment or SAGE.
Speaker 1: This was a network that aimed to coordinate the numerous
Speaker 1: radar stations the US commanded and to use those sites
Speaker 1: to create a coordinated and unified image of US airspace.
Speaker 1: So if you've ever seen any of those military movies
Speaker 1: where people are looking at a whole bunch of different
Speaker 1: screens that make up the United States, that is a
Speaker 1: representation of what this was. Not necessarily an accurate one,
Speaker 1: but that's what they were trying to do. And I
Speaker 1: could do a full episode about SAGE, but we're really
Speaker 1: interested in the modem part, as the modems are what
Speaker 1: allowed the computer systems in SAGE to send data back
Speaker 1: and forth with each other. Bell Labs developed the one
Speaker 1: oh one data set modem in ninety eight as sort
Speaker 1: of a part of this process, and some sources say
Speaker 1: the one oh one was later introduced as a commercial product.
Speaker 1: Others disagree. They say a follow up modem, the Bell
Speaker 1: one oh three, was the first commercial modem. I don't
Speaker 1: know who's right, but in any case, these commercial modems
Speaker 1: weren't for the average person. Anyway, when we're saying commercial modem,
Speaker 1: we don't mean that the average you know, human being
Speaker 1: would go out and buy one of these in a store.
Speaker 1: Computers were not for the average person. These were typically
Speaker 1: attached to mainframe style systems that could communicate directly with
Speaker 1: other main frame systems, typically of the same type. And
Speaker 1: this was just one piece of the puzzle that was
Speaker 1: necessary for a computer networks. Another big piece of that
Speaker 1: puzzle was the telephone network itself. Okay, so back in
Speaker 1: the nineteen fifties and nineteen sixties in the United States,
Speaker 1: A T. T had a monopoly on the telephone system.
Speaker 1: They called all the shots as far as phones go.
Speaker 1: They owned essentially all the regional companies that provided telephone
Speaker 1: service in the United States. No matter who your phone
Speaker 1: company was, ultimately it was owned by A T and T.
Speaker 1: If you were in the US, people didn't actually own
Speaker 1: their telephones. The phone company owned those phones. You would
Speaker 1: pay for phone service and a phone would come with it,
Speaker 1: and technically you'd be leasing the phone. The phone company
Speaker 1: also had an iron grip on what could connect their network. Now,
Speaker 1: the phone company argued, and when I say phone company,
Speaker 1: I mean A T and T. A T D argued
Speaker 1: that the reason for this was because they didn't want
Speaker 1: anyone to connect anything else to the network because it
Speaker 1: might deteriorate the performance of the entire network. So they said,
Speaker 1: we don't want to risk that. This is an important
Speaker 1: telecommunications infrastructure. So the company argued successfully that it should
Speaker 1: be allowed to dictate what could and could not be
Speaker 1: connected to the phone network. The United States government agreed,
Speaker 1: and that was passed into law. Now, lots of engineers
Speaker 1: were developing technologies that could send signals over phone lines,
Speaker 1: including stuff like modems, but A T and T wanted
Speaker 1: to restrict the network so that only products from A
Speaker 1: T and T itself would ever be allowed on their
Speaker 1: own phone infrastructure or even connect to the physical hand sets.
Speaker 1: You wouldn't be allowed to make a peripheral for a
Speaker 1: phone hand set because people, you know, individuals didn't own
Speaker 1: those telephones A T and T did. This came to
Speaker 1: a head in nineteen fifty six when a case went
Speaker 1: to the d C Circuit Court of Appeals. It had
Speaker 1: already been decided in a lower Court got appealed, moved
Speaker 1: up to the Circuit of Appeals Court, and it was
Speaker 1: called Hush A Phone Corporation versus the United States. Now.
Speaker 1: The company hush a Phone produced a pretty simple product.
Speaker 1: It was meant to attach to the speaker side of
Speaker 1: a phone hand set. So this is the part you
Speaker 1: would hold up to your ear with an old telephone,
Speaker 1: and this was a little cup that fit on the
Speaker 1: end of that speaker. It would cup over your ear.
Speaker 1: It was meant to provide some extra privacy because it
Speaker 1: it's like, you know, if you're whispering into someone's ears
Speaker 1: and you cut your hands around so that no one
Speaker 1: can hear you whisper. That's why it was called hush
Speaker 1: a phone. People wouldn't be able to suss out what
Speaker 1: was going on if they were trying to eavesdrop. It
Speaker 1: also would help you hear what was being said more clearly.
Speaker 1: A T and T claimed that the Communications Act of
Speaker 1: ninety four gave A. T and T the authority to
Speaker 1: forbid the sale of these hush a Phone attachments. The
Speaker 1: company claimed that they could lead to a deterioration of
Speaker 1: phone service, and the first court agreed with them, but
Speaker 1: it got sent up to an appeals court and they said, what, No,
Speaker 1: attaching a cup to a speaker is not going to
Speaker 1: deteriorate the entire phone service. That's not how the phone
Speaker 1: service works. If anything, it will affect one part of
Speaker 1: the phone service, and that is the person who's using
Speaker 1: the darn thing it is. This is not an issue.
Speaker 1: They struck it down, and this opened up the door
Speaker 1: to third party peripherals that could indirectly connect to the
Speaker 1: phone company. They could not directly connect into the phone infrastructure,
Speaker 1: but it gave the opportunity to create something that could
Speaker 1: work in tandem with it, and it meant that other
Speaker 1: companies began to look into this. I'll explain how that
Speaker 1: developed a little bit more in just a second, but
Speaker 1: first let's take another quick break. A T and T
Speaker 1: s Bell Labs introduced the one oh three in the
Speaker 1: early nineteen sixties, and the one oh three modem had
Speaker 1: a transmission speed of three hundred baud. That's three hundred
Speaker 1: bits per second. Not that speed, it would take you
Speaker 1: nearly eight hours to transfer a file that was one
Speaker 1: megabyte in size. Now, of course, most files of the
Speaker 1: time were significantly smaller than one megabyte. Even so, a
Speaker 1: single character, you know, a letter or a number or
Speaker 1: a symbol like you know, uh, an interaro bang or
Speaker 1: a dollar sign or anything like that. It would require
Speaker 1: eight bits to encode. That's one byte, So a three
Speaker 1: hundred baud modem could send about thirty seven characters per
Speaker 1: second technically thirty seven and a half. But half a
Speaker 1: character's meaningless unless you're, you know, a big fan of
Speaker 1: the Twilight series or something. Meanwhile, a scientist named Robert
Speaker 1: veit Brecht was working on a technology to help deaf
Speaker 1: people communicate using telephone lines. Vite Brecht himself was born deaf,
Speaker 1: and his innovation used a device called an acoustic coupler.
Speaker 1: And this was a third party periph role that a
Speaker 1: T and T would have likely shot down before that
Speaker 1: court decision made from a few years earlier, and that
Speaker 1: it totally weakened a T and T s case. The
Speaker 1: acoustic coupler was a special cradle that could hold a
Speaker 1: telephone handset. They gotta remember, a T and T owned
Speaker 1: all the telephones, so pretty much all the telephones were
Speaker 1: the exact same form factor, so it's really easy to
Speaker 1: build a one size fits all peripheral. Because he knew
Speaker 1: what the phones were going to be like, So the
Speaker 1: handset would essentially go into two kind of rubber cups,
Speaker 1: and you would put the handsets speaker to go against
Speaker 1: the coupler's microphone, and the handsets microphone would go up
Speaker 1: against the coupler's speaker. Vipbrect hooked this up to a teletypewriter.
Speaker 1: It was an extension of the teletype idea I talked
Speaker 1: about earlier. And here's how it worked. Now. Both of
Speaker 1: them have teletypewriter machines with acoustic couplers, So they each
Speaker 1: put their phones handset into those acoustic couplers, connecting the
Speaker 1: whole system together. Person one would type a message on
Speaker 1: their teletypewriter and that would then send a signal to
Speaker 1: the acoustic coupler, which would convert that signal into audio,
Speaker 1: and the audio would transfer over the phone line just
Speaker 1: as that. What if they were having a voice conversation
Speaker 1: two person number two's handset, which is in you know,
Speaker 1: another acoustic coupler, The audio plays out over the handsets speaker.
Speaker 1: The acoustic coupler picks up that audio, converts it into
Speaker 1: another signal which goes to the teletypewriter and then prints
Speaker 1: the message. That person number one had originally typed. What
Speaker 1: made this invention more useful was the creation of teletypewriter
Speaker 1: relay services. An entire language was even developed around it
Speaker 1: because communication could only go one way at a time,
Speaker 1: similar to using a walkie talkie or CB radio, So
Speaker 1: you have certain phrases that indicate when you are done speaking,
Speaker 1: you know, like with walkie talkies you might say over
Speaker 1: to indicate you're done. The acoustic coupler would allow for
Speaker 1: a wider adoption of modems and also allowed other companies
Speaker 1: besides A T and T, the opportunity to make modems themselves.
Speaker 1: After all, the modems were not directly connecting into the
Speaker 1: phone networks. Nothing was getting plugged into the phone network itself.
Speaker 1: They were just sending audio signals over telephones, actual telephone handsets.
Speaker 1: They just happened to be a carrier signal for digital
Speaker 1: information as opposed to a voice telephone call. It was
Speaker 1: a great work around. Now, if you've seen the classic
Speaker 1: nineteen eighties film War Games, which stars Matthew Broderick as
Speaker 1: a precocious hacker, you've seen an acoustic coupler because Broderick
Speaker 1: uses one and he puts his phone into his phone
Speaker 1: handset into an acoustic coupler when he hacks into systems
Speaker 1: in that film. Over the years, companies made more advanced modems,
Speaker 1: but the customer base was still pretty limited in the
Speaker 1: sixties and seventies, because we have to remember it wasn't
Speaker 1: until the mid nineteen seventies that personal computers were even
Speaker 1: a thing so typically, so really we were talking about
Speaker 1: research facilities, a few companies, some gun or Mint, and
Speaker 1: some military offices, and mostly they were just talking to
Speaker 1: branches of themselves. They weren't cross talking because there wasn't
Speaker 1: really a network set up yet. Some other important events
Speaker 1: that helped establish the foundation for modems include the creation
Speaker 1: of a standard called r S two thirty two. RS
Speaker 1: stands for Recommended Standard. This was another technology being developed
Speaker 1: around the same time as the evolution of modems, so
Speaker 1: early nineteen sixties. It's a standard for serial communication for
Speaker 1: the transmission of information, and serial communication means that this
Speaker 1: method sends data one bit at a time in sequence,
Speaker 1: as opposed to parallel communication, in which you could send
Speaker 1: data in parallel channels all at the same time. By
Speaker 1: establishing a standard, companies didn't have to invent a new
Speaker 1: method for a computer to send data to some other device,
Speaker 1: such as drumroll please a modem. By the time personal
Speaker 1: computers were coming around, the RS two thirty two standard
Speaker 1: was well established, and it was pretty typical to find
Speaker 1: at least one serial port on a PC. These could
Speaker 1: connect to things like modems, printers, computer mice, all sorts
Speaker 1: of stuff. Meanwhile, a group of scientists, with the backing
Speaker 1: of the U. S Department of Defense, were hard at
Speaker 1: work creating a different set of standards. These standards would
Speaker 1: set the rules for how computers could send information across
Speaker 1: a network. You know, how would those messages take form,
Speaker 1: how would you do error correction? How would you make
Speaker 1: sure the entire message gets through? These rules would lead
Speaker 1: to the formation of the ARPA net, a sort of
Speaker 1: predecessor to the Internet, and then further go on to
Speaker 1: evolve into the rules that guide data transmission across the
Speaker 1: Internet itself. On the telephone infrastructure front here in the
Speaker 1: United States, the government began to pass regulations on the industry,
Speaker 1: forcing A T and T to make concessions to consumers. Ultimately,
Speaker 1: later on the government would break A T. T up
Speaker 1: into several regional companies. Because of that monopoly, I talked
Speaker 1: about earlier and later most of these would just coalesced
Speaker 1: T one thousand like back into a T and T,
Speaker 1: but that's a different story. One of those regulations, which
Speaker 1: was passed in the nineteen sixties had to do with
Speaker 1: the creation of the r J eleven connector also known
Speaker 1: as the phone jack. Earlier, phones were typically hardwired into
Speaker 1: houses with no jack at all. You couldn't disconnect the phone.
Speaker 1: It was wired directly into the wall. You couldn't plug
Speaker 1: anything else into the phone line because the other end
Speaker 1: of the phone line was inside the telephone. There was
Speaker 1: no access to it. But the r J eleven jack
Speaker 1: meant you could do that. You could detach the wire
Speaker 1: from a phone and put it into something else, like
Speaker 1: a modem. Now, it was introduced in the nineteen sixties,
Speaker 1: but it wasn't until the US government passed regulations requiring
Speaker 1: their implementation in the mid nineteen seventies, so it took
Speaker 1: a decade before they were actually starting to really be
Speaker 1: implemented on a widespread basis. Now you could build a
Speaker 1: device like a modem and plug a phone cable directly
Speaker 1: into the modem itself, rather than using an acoustic coupler
Speaker 1: to do this kind of halfway thing with the phone
Speaker 1: handset plugged into the coupler. This would also allow modem
Speaker 1: manufacturers to make faster modems with lower error rates. So
Speaker 1: all of this is happening, and by the time we
Speaker 1: get the early PCs, a lot of these technologies were
Speaker 1: standardized and starting to mature. And that's a good thing
Speaker 1: because it meant that we as consumers weren't faced with
Speaker 1: tough choices that could come back to bite us. Now,
Speaker 1: imagine if we had to choose between different ways to
Speaker 1: connect to other computers and other peripherals. It would really
Speaker 1: limit the types of computers we could select, right, because
Speaker 1: whatever computer we select would determine what sort of peripherals
Speaker 1: we could use and what sort of other machines we
Speaker 1: could communicate with. We wouldn't have just one Internet. We
Speaker 1: would have dozens of Internet all dependent upon their own
Speaker 1: proprietary hardware and their own proprietary protocols. It would be awful.
Speaker 1: It would also be a lot like the early days
Speaker 1: of online service providers, where it was really typically pretty
Speaker 1: easy to communicate with other folks who were on that
Speaker 1: same osp but it was a lot harder or sometimes
Speaker 1: impossible to send messages to someone who was using a
Speaker 1: different online service provider, which was gross and yet another
Speaker 1: thing that was evolving around this time, where the various
Speaker 1: data compression protocols. Compressing data became an important part, not
Speaker 1: just because of storage space, and it was so precious
Speaker 1: in those early days. I still remember when I thought
Speaker 1: two fifty megabytes of storage was going to be more
Speaker 1: than any person would ever need in their lifetime. It
Speaker 1: was also important because if you could compress data down
Speaker 1: so you were working with smaller file sizes, the transfers
Speaker 1: wouldn't take as long, which I guess is pretty self evident.
Speaker 1: But all of these things had to happen to make
Speaker 1: computer communication practical for the average person. The first consumer
Speaker 1: modem that you could plug directly into a phone line
Speaker 1: without the need for a handset was the Haze smart modem,
Speaker 1: which first hit the market sometime in the late nineteen
Speaker 1: seventies early nineteen eighties. Until then, you were using acoustic couplers.
Speaker 1: But then very few folks in the world had a
Speaker 1: computer in the first place. Even fewer of those had
Speaker 1: any need to connect their computer to some other computer,
Speaker 1: so it wasn't an enormous problem for most people. Other
Speaker 1: companies would follow Hayes's model and create similar modems, and
Speaker 1: they would compete with Hayes, and Hayes would just sort
Speaker 1: of hang on until the early nineteen nineties, and ultimately
Speaker 1: it would have to file for bankruptcy. But what about
Speaker 1: that sound I played at the beginning of this episode.
Speaker 1: What is the sound of a dial up modem all about? Well,
Speaker 1: those sounds you hear, those tones you hear, and the
Speaker 1: noise you hear, they all represent a sequence that modems
Speaker 1: would go through in order to establish a connection, so
Speaker 1: that communication could actually happen between modems when you wanted
Speaker 1: to dial into a service, whether it was a bulletin
Speaker 1: board service, an online service provider, or later on an
Speaker 1: Internet service provider. Here's what generally happens with a dial
Speaker 1: up modem. First, you hear the dial tone of the phone,
Speaker 1: followed by the sound of your modem dialing in whatever
Speaker 1: phone number you had programmed in for your service. You
Speaker 1: would then hear the phone ring and then pick up
Speaker 1: on the other end. You would then hear a cacophony
Speaker 1: of noises. But those noises established how the modem on
Speaker 1: your computer could communicate with the modem on the other
Speaker 1: end of the call. The earliest sounds, essentially are the
Speaker 1: modems saying how fast they can go. I remember when
Speaker 1: I was a kid, we still had a pretty slow modem.
Speaker 1: At first. I think it was a baud, so two thousand,
Speaker 1: four hundred bits per second. Still not super fast. But
Speaker 1: this is the process of a modem saying, actually, this
Speaker 1: is how fast I can go. This is how much
Speaker 1: data I can send per second, how about you. The
Speaker 1: next sequence of sounds established the basic rules of data transfer,
Speaker 1: including the sin ACT handshake. That's s Y N dash
Speaker 1: a c K. SINAC was that will send actually stands
Speaker 1: for synchronization, and it's all about synchronizing sequence numbers. Because
Speaker 1: even decades after that early work with the teletype, synchronization
Speaker 1: is still very important. Act stands for acknowledge. So a
Speaker 1: sin ACT handshake describes a sequence in which one modem
Speaker 1: initiates synchronization and the other modum says, yeah, I got you.
Speaker 1: After that comes the actual rate negotiation segment. Earlier, the
Speaker 1: two modums said hey, this is how fast I can go.
Speaker 1: But this is where they say, here's how fast this
Speaker 1: transaction will go. Here's how quickly we will pass data
Speaker 1: to and from one another. Then we go to a
Speaker 1: sound that indicates that a connection has been established, that
Speaker 1: all the rules have been agreed upon, and the two
Speaker 1: modems are ready to communicate. And then the next sound
Speaker 1: you will hear as actual throughput, the actual data going
Speaker 1: to the other machine. And then typically the external speaker
Speaker 1: on the modem will shut off and you won't hear
Speaker 1: the noise anymore. But anyone who picks up the phone
Speaker 1: on your line would hear the noise, and that would
Speaker 1: also really screw up your modem connection. I hate when
Speaker 1: that happened. That happened a lot when I was going
Speaker 1: on bulletin boards back when I was a kid. All
Speaker 1: of this communication still has to happen within that band
Speaker 1: of audio frequencies that make up the voice band on
Speaker 1: the phone. Infrastructure technology is meant to improve phone communication.
Speaker 1: Stuff like echo cancelation and noise reduction would also end
Speaker 1: up helping modem technologies. Companies could boost data transfer speeds
Speaker 1: by making the modulation on that carrier wave more subtle
Speaker 1: and thus cram more bits per second transfers. So we
Speaker 1: saw bad rates go up. You know, it started off
Speaker 1: at like twelve hundred bad hundred hundred nine hundred fourteen
Speaker 1: point four kill a bits because I KILLO was a thousand,
Speaker 1: soy point eight kill a bits. And then finally we
Speaker 1: hit fifty six K, the gold standard for dial up Internet.
Speaker 1: The birth of the Web drove a demand for modems,
Speaker 1: and the evolution of content on the Web meant that
Speaker 1: even if you had a fifty six K dial up modem,
Speaker 1: you were not getting data transfer speeds fast enough to
Speaker 1: really take advantage of what the Web was having to offer.
Speaker 1: That's when we started to see the rise of broadband
Speaker 1: solutions like DSL and cable modems. But these weren't really
Speaker 1: modems at least not like the kind that performed the
Speaker 1: modulation and demodulation processes of dial up modems. See, the
Speaker 1: older modems were necessary because they had to convert that
Speaker 1: digital signal into an analog signal and then back again.
Speaker 1: But cable and DSL modems don't do that. They deal
Speaker 1: in digital. The data never has to transform to another format.
Speaker 1: So the modems are still necessary in order to facilitate communication,
Speaker 1: but they're not translating. They're not actually doing modulation demodulation anymore,
Speaker 1: the way the dial up modems were, so really if
Speaker 1: you want to look at a modern technology that's closer
Speaker 1: to what dial up modems are like. You could think
Speaker 1: of WiFi as being that, because WiFi is all about
Speaker 1: taking digital information and encoding it into radio waves, broadcasting
Speaker 1: it out to a receiver, which then accepts those incoming
Speaker 1: radio waves and converts them back into digital information that
Speaker 1: the computer can handle. These are closer to what the
Speaker 1: old dial up modems used to do, and there is
Speaker 1: a brief overview of dial up modems. Some people still
Speaker 1: use them, not very many, and they were an incredibly
Speaker 1: important technology for me as a kid. I'll never forget
Speaker 1: when I finally converted from dial up to k BOWL
Speaker 1: never had DSL, but I went to cable modems and
Speaker 1: uh yeah, that was a big, big jump. And one
Speaker 1: of these days I hope to have fiber. Hasn't happened yet.
Speaker 1: My I s P doesn't offer it, and there's no
Speaker 1: other competing I s P in my neighborhood that offers it,
Speaker 1: so I'm stuck with cable, but still an improvement over
Speaker 1: a dial up. I hope you guys enjoyed this episode.
Speaker 1: Maybe you have a deeper understanding of how modems work
Speaker 1: and what their purposes, I hope. So, if you have
Speaker 1: any sort of suggestions for future episodes, maybe it's a
Speaker 1: technology or a company or person in tech. Maybe it's
Speaker 1: just a trend you would like me to cover, reach
Speaker 1: out to me on Twitter or Facebook. It's the best
Speaker 1: way to get in touch with me, and the handle
Speaker 1: for both of those is tech Stuff H s W.
Speaker 1: I'll talk to you again really soon. Text Stuff is
Speaker 1: an I Heart Radio production. For more podcasts from my
Speaker 1: Heart Radio, visit the i heart Radio app Apple Podcasts
Speaker 1: wherever you listen to your favorite shows.