The Birth of the Modem

when we got the IBM Compatible. I don't remember exactly when my dad got our first modem, or whether it was on the Apple to E or on the two eight six IBM Compatible or one of the later ones, because we got a three eight six from there. But one thing I do remember really well was a particular sound. Any of you guys out there around my age or so we'll remember that noise too. Some of you younger folks might have heard it before, and a few of you might still use one. I mean, they're not obsolete,

but they are the exception rather than the rule. And to the rest of you that probably sounds entirely foreign, and it is the sound of a dial up modem making a connection. So in today's episode, I'm going to talk about modems, specifically dial up ones. Before I launch into my trademarked history section, let's talk about what a modem actually does. A modem's purpose is to facilitate communication between computers, and the word modem is a portmanteau, which

means I get to revel in my background in English lit. So, a portmanteau is a word that combines both the meaning and the sounds of two or more other words, and typically we do this to convey a particular concept or meaning. So, for example, brunch, something I miss dearly during this time of isolation, is a portmanteau. It combines the sounds from the words breakfast and lunch, and it also combines the

meaning of those two words. Brunches a meal that occurs later than breakfast but earlier than lunch, and typically the menu for brunch includes foods that you might encounter at either of those other meals. So what words and ideas combine to form the word modem, Well, that would be modulation and demodulation. I'll explain that a little bit later in this episode, but first let's dive into some history

to understand the genesis of modems for computers. It actually helps for us to go even further back to talk about the telegraph, which I know sounds crazy, but hear me out way back in the mid nineteen century. So the mid eighteen hundreds, inventors, including the famous Samuel Morse, we're developing a method of communication that depended upon sending electric signals over wires, and it was ingenious in its simplicity.

So on one end, you've got a switch. If you close the switch, you let current pass through a circuit into a wire. If you open a switch, you cut off that path. The current cannot flow through. Now, this particular switch was spring loaded. If you pushed down on a little button, you closed the switch. If you let off pressure, if you took your hand the way, it would spring back into the open position. So it was

only closed if you held it closed. On the opposite side of that wire was the receiver, and the receiver had an electro magnet in it, so when current flowed to the electro magnet, it would generate a magnetic field. That's all electro magnets were, right. The current flows through,

it generates a magnetic field. This magnetic field would then pull down a ferromagnetic lever, And so if you hold down the switch on the sending end, the lever on the receiving end would stay down because the electromagnetic force would continue to pull on it. If you let go of the switch, the lever on the opposite side would pop back up once that electro magnetic attraction stopped. You can also have it just be some sort of buzzer

or alarm. So you hold down the switch and it makes an electro magnet sound, a bell or a buzzer. Now that by itself is not terribly useful, but one thing you could do is establish a pattern and determine what meaning there is in the pattern. So, for example, if you were to hold down the switch for a little bit, that might be a dash. If you just tapped the switch, you would get a dot. And then by establishing what dots and dashes mean, you could build

out a code. That's exactly what Morse did. He developed his eponymous code, the Morse Code, to encode characters into collections of dots and dashes. You could take a message written in a language like English. You convert every letter in that message into its respective dots and dashes. You send it off by telegraph by tapping this message out on the sending end, and an operator on the receiving end would listen to those taps, knowing whether it's a

dot or a dash. They would take down the message and to code it back into its original language. You know, if they were really good, they could do it letter by letter. Otherwise they were actually writing down dots and dashes. A little bit later, you had engineers who created a version where the receiving end had a lever where it ended with a little wheel that was coded in ink, and there was paper tape that would constantly move at

a speed built neath the lever. So when the sender pressed the sending key down, the receiving key would come down and that wheel would make contact with the paper. And then based upon the length of the switch press, you would get a physical dot or dash. You would actually get a printed version of the coded message which you could then decode. Then thus you would say the transcription step where someone would have to take down the

dots and dashes by hand. Now trust me, this is all going to lead into modems, but we do have a couple of other stops. We have to make first. There was a lot of work in the field of teleprint ters in the nineteenth century, including stuff like stock tickers that would take in an electric signal and then print out results based on that. But we're gonna jump over all of that for right now to get to

the early twentieth century. In nineteen o two, an electrical engineer named Frank Peern was experimenting with a method to create a printing telegraph system that would let people send and receive text messages, essentially using typewriter like devices that would connect to each other via wires. You could have dedicated wires between two of these things, or you could

have them tap into some other wired system. He encountered some challenges along the way, and after a few years of frustration, Peern decided he's going to piece out of this whole endeavor. But then his work was carried on by another engineer named Charles Crumb. The goal was again to make an automated system that could receive incoming messages and print them in alpha numeric characters on paper, so instead of getting those dots and dashes, you would get

the original message. As it was intended, it was skipping the whole encoding decoding step. You wouldn't have to put a message into morse code and then decode it. At least it was skipping in as far as the human operators were concerned. It was taking all of those sort of intermediate steps required by traditional telegraphy and automating them. But how well, it comes back to the idea of using electric pulses to indicate a letter, So it really

comes back to that closed and open switch description. The engineers coded each character as a series of five potential electric pulse states, and the states were either on meaning current was flowing through the circuit at that instant, or off meaning no current was flowing. And they represented each letter as a sequence of either on or off, and that's sequence would include five pulses. They referred to the on current state as marking and the off current state

as spacing. So the letter D, for example, would code into mark space space mark space, meaning the current would be on, off, off, on off as its sequence of five pulses. The receiving machine would interpret the incoming signals as letters. It would say, all right, we're looking at this span of time and we see that the current is on off, off, on, off. That's the letter D. The code itself dated all the way back in the

eighteen seventies. It was invented by Emil Baudoux Bado that's b a U d O. T made numerous contributions to the field, including a method of multiplexing, that is, being able to send multiple messages simultaneously through a careful system of clockwork switches so that the correct information would go to the correct teleprinter. His work was important enough that we take his name Baudo, and we created the unit for data transmission with modems, the baud b a U D.

More on that in just a moment. But this approach required one other very important component. The sending and receiving machines had to be quote in step, meaning they had to be synchronized with each other. If they weren't, then the receiving machine might start interpreting signals out of step, out of sync with the sending machine, and thus print the wrong letters. Because remember every character coded into a

signal of five pulses. If the receiving machine is off by even one pulse, it's going to misinterpret what's being sent to it. So if you were sending a message that was five letters long. Those five letters would be represented by twenty five short pulses, five pulses each, and the first letter would be pulses one through five, the second letter would be pulses six through ten, and so on. But let's say the receiving machine only starts to pick up at pulse three. It misses the first two pulses.

It thinks pulse three is actually pulse one, which means it's going to use the pulses three through seven to be the first letter, and the pulses eight through twelve will be the second letter, and so on, with the final letter having two spaces at the end because no more signal is being sent. While the engineers were able to create a way to send and receive signals, it was this synchronization stuff that would be a really big challenge.

They had to make sure that both machines knew quote unquote when messages were coming through, so that any errors that were detected would be known and it wouldn't just print gibberish. The solution turned out to be fairly elegant. Howard Crumb, the son of Charles Crumb, proposed that every code combination representing a letter would first be preceded by

a start pulse and followed by a stop pulse. So every single letter would have a special pulse at the very beginning and the very end of that sequence of five to indicate this is the beginning of a letter, this is the end of a letter, ignore anything else. That way, the receiving machine would detect the true beginning and the true end of each combination, and would more likely print the appropriate letter. It was a simple way to achieve full synchronization, though there was still no error

correction at this point. Now I'll have to dedicate a full episode to teletype and the advancements that made it possible, because there's a whole lot more than that brief overview I just gave. But what does this all have to do with modems. Well, the process of encoding information and sending it through a signal is modulation. The process us of receiving a signal and decoding that to get at the original information is demodulation. The same process is used

in lots of other technologies like radio. With radio signals, you take a carrier wave, that is a radio wave with a consistent amplitude and a consistent frequency. It would just be a pure tone if you could hear it, if it were in the range of human hearing. So you get this pure radio wave. Now you encode information by laying on another wave, by altering that wave in some way, you can change the amplitude. If you do it through those changes, you get what is amplitude modulation

or a M radio. Or you can change the frequency and you get frequency modulation or FM radio. The receiver on the other end follows the same process in reverse. It takes these waves in and then converts them back into the original information that was sent out, like you know, your your pop radio station or whatever it is you're listening to. So really this is all about creating a reversible process that lets you translate information into some other

format and then back again on the other side. Now, in the nineteen twenties, countries around the world slowly began building out telephone infrastructure, and there was now the opportunity to piggyback the infant teletype technology onto the phone infrastructure, except for the fact that phone companies were pretty dead

set against it. Previously, these machines relied upon purpose built wires, but that limits their use right, and you can only send messages to whichever machines are hardwired to your machine. That doesn't really give you a whole lot of options. What if you wanted to send it to somebody else whose machine wasn't directly connected to yours, You'd be stuck. The telephone network would allow for a lot more connectivity and had a lot more infrastructure that was already established.

One early approach was to use non switched telephone lines that were dedicated for the sorts of connections. These are called least lines because these lines were meant only for that kind of process and would not be used for phone to phone conversations. But that was really expensive. It would be way more cost effective and more useful to tap into the general telephone network, but there needed to

be a couple of things for that to happen. One, you had to get it past the telephone company, which essentially in the United States was a T and T, and another one you had to find a way to modulate and demodulate the information so it could transmit over phone lines. There had to be a way to have two teletype machines establish a connection with one another and

transmit and receive messages. At the time the phone infrastructure in the United States was capable of carrying sound frequencies between three hurts and three killer hurts, also known as the voice band. Now, that's a pretty narrow range of frequencies, and you could think of frequencies as being related to pitch. Lower frequent sees have a lower pitch. Higher frequencies have

a higher pitch. But the range of human hearing goes from twenty hurts to twenty killer hurts, So the voice band represents only a small slice of the full range of human hearing. It also means that any solution that would convert information into audio to transmit over phone lines would have to work within those limitations. Oh and here's another fun fact. We call this system the plain old telephone service or POTS. Now it's been updated since then, but it took a long time for that to happen.

The United States was relying on POTS until the late nineteen eighties, so it was a venerable technology by the time we finally got off of that. The teletype example is also important not just because of modulation demodulation, but because it would help inform future engineers as they began to think about creating methods for computer systems to communicate with one another. Keep in mind that the early computer systems were all independent. They were mainframe systems that performed

like an isolated island. You needed physical access to the machines or two dumb terminals that were connected to those machines in order to make any use of them. Communication with other computers wasn't really a possibility for numerous reasons. One was that different computers effectively spoke different languages, so a program written for one type of computer would not work on another, just as a program written for a Mac computer won't run natively on a Windows based machine.

But another reason was just that there was no interface through which computers could send or receive information with one another. When we come back, we'll talk about how that would begin to change, But first let's take a quick break. The development of modems, which weren't yet called modems, or were they actually for computers just yet, would coincide with

other trends in technology. Now. As we've learned in many episodes, the development of tech rarely follows a straight timeline where event A leads to event B, which leads to events see. Usually you're actually talking about multiple timelines of multiple technologies and they ultimately either converge or at least cross paths,

so it makes it complicated to tell the history. So while companies were working with teleprinters and teletype machines as well as fax machines, which are somewhat related, other engineers were working on building out computer systems. World War Two

demonstrated how computer systems could be really important. In addition, the British developed radar technology, and it was obvious that being able to share radar information quickly across great distances like coast to coast in the United States, would be advantageous. It would be really useful if a radar station and say Hawaii, could send information back to the mainland in real time. That all that stuff could be monitored from

a centralized location. Now here's a big challenge. Ever since Aniak hit the scene in the nineteen forties, computers have primarily fallen into the digital category, and digital information is different from the way information would transmit over phone lines. This leads us to talk about the difference between digital and analog. This is incredibly important for modems. So we can think of the analog world as being the world

of infinite variability. Everything is infinitely variable. You can change something like the brightness of a light to an infinite degree of variability. You can always go a little less bright, or maybe a little more bright, or maybe half as bright as you just went the last time, or half as dim. You can keep dividing that up into finer and finer adjustments with no limitations. If we took the number ten and we cut it in half, we would

have five. If we cut in half again, we have two point five, and we can keep cutting that in half forever. We can do that until we're just exhausted. So an analog recording is one that captures all the variations in a continuous signal. The digital world doesn't do that. A digital signal deals with discreete It deals with the finite. Computer's capabilities will determine how many values any given signal can possess. The more powerful the computer, the more values

it can handle. With enough values, the signal can seem to be almost like an analog one, because you've got enough information to describe that signal that upon casual glance or even careful examination, it looks the same as an analog signal. But this requires an awful lot of information to accomplish. One way to think about this is to consider a film photograph versus a digital photograph. Film is analog. Digital photography is well, I mean it's in the name, right,

it's digital. So we've all heard about megapixels, right. Megapixels referred to a camera's ability to compose an image with a certain number of points of color or light, and it's all about a camera's resolution. If we had a camera with a really low resolution, I mean, like ludicrously low, let's say eight by eight pixels, that would mean that the images would consist of eight blocks across an eight blocks tall, which means that the entire image would consist

of just sixty four blocks. That would be a really blocky image. It would be hard to even know what you were looking at unless it was a super simple shape. If you increase the resolution, that means you're decreasing the size of those pixels. You're decreasing the size of those blocks, and you're cramming more of them into there so that you can represent the image with more blocks, smaller blocks,

creating a smoother, less blocky image. If you keep doing that, eventually you get to a resolution that's high enough that our human eyes can't really pick up on the pixel blocks at all, and to us it just looks like a photograph on film. But again, it takes a lot of information to get to that point. Here's another challenge.

How do you take the information a computer deals with, which is in digital binary format, these discrete packets of information, and then how do you send that out over a phone line which carries an analog signal over physical copper wire. You have to create a way to translate the information from digital into analog. You have to modulate the computer data so it can pass over onto an analog transmission system.

Then on the other end, on the receiving end, you need a device that can accept this incoming analog transmission and demodulated translating it back into binary information for the receiving computer to process. This is true for tons of different input and output scenarios, not just computers communicating across phone lines. Anytime you're using a computer system or you know, a digital system to record or analyze stuff out in the world, you're typically relying on a digital process to

measure an analog phenomenon. Same is true if you were using, say an analog joystick to play a video game. The analog controls, which might include a potentiometer that tells the device how far you're pushing the joystick in any given direction. That has to be converted into digital information for the computer to do anything useful with it. But let's get back to modems, particularly so the way a modem actually modulates data starts with a carrier wave, just like with

the radio. Now, you could technically communicate in a very basic way just by either turning the wave on or off. Right, you could say, all right, well, when it's on, that's a one, and it's off it's a zero. But that's not necessarily the best option. Another way is to alter the carrier wave in some fashion. You can tweak the amplitude or the frequency, just like with a M or FM radio. So modems take a basic carrier wave function and then alter it in some predetermined way to communicate

digital data. The receiver on the other side gets this carrier wave with alterations, and it understands the whole process that was made to encode that information, so it just reverses it. It decodes the information and gets those delicious zeros and ones at the heart of everything. The speed at which a modem can transmit information is measured in

bits per second. A bit, remember, is one unit of binary information, so it's either a zero or a one, and the unit we used to measure modem speed is the baud be a u D named after a meal bodo bad refers to a symbol rate, and really that means how many times a transmission signal changes every second. More changes per second indicate more data carried by that

signal per second. Now, typically we think of this as a faster transmission speed because it reduces the time it takes to transmit any given file, but really what it means is we're able to send more data at a time. One BOD is the equivalent of one bit per second. Now, I wish I could tell you the name of the person or persons who first created computer modems, but that

information is lost. And honestly, there was so much work in this area across so many different people in different organizations, all of whom made contributions that I really cannot do that. They were all in different parts of the world, they're all working towards a similar goal. I can tell you that the first commercially available modem came out of a T and t. The company, through its R and D branch, Bell Labs, was working with the North American Air Defense

COME and also known as nora AD. Nora AD had a computer system called the Semi Automatic Ground Environment or SAGE. This was a network that aimed to coordinate the numerous radar stations the US commanded and to use those sites to create a coordinated and unified image of US airspace. So if you've ever seen any of those military movies where people are looking at a whole bunch of different screens that make up the United States, that is a

representation of what this was. Not necessarily an accurate one, but that's what they were trying to do. And I could do a full episode about SAGE, but we're really interested in the modem part, as the modems are what allowed the computer systems in SAGE to send data back and forth with each other. Bell Labs developed the one oh one data set modem in ninety eight as sort of a part of this process, and some sources say the one oh one was later introduced as a commercial product.

Others disagree. They say a follow up modem, the Bell one oh three, was the first commercial modem. I don't know who's right, but in any case, these commercial modems weren't for the average person. Anyway, when we're saying commercial modem, we don't mean that the average you know, human being would go out and buy one of these in a store. Computers were not for the average person. These were typically attached to mainframe style systems that could communicate directly with

other main frame systems, typically of the same type. And this was just one piece of the puzzle that was necessary for a computer networks. Another big piece of that puzzle was the telephone network itself. Okay, so back in the nineteen fifties and nineteen sixties in the United States, A T. T had a monopoly on the telephone system. They called all the shots as far as phones go. They owned essentially all the regional companies that provided telephone

service in the United States. No matter who your phone company was, ultimately it was owned by A T and T. If you were in the US, people didn't actually own their telephones. The phone company owned those phones. You would pay for phone service and a phone would come with it, and technically you'd be leasing the phone. The phone company

also had an iron grip on what could connect their network. Now, the phone company argued, and when I say phone company, I mean A T and T. A T D argued that the reason for this was because they didn't want anyone to connect anything else to the network because it might deteriorate the performance of the entire network. So they said, we don't want to risk that. This is an important

telecommunications infrastructure. So the company argued successfully that it should be allowed to dictate what could and could not be connected to the phone network. The United States government agreed,

and that was passed into law. Now, lots of engineers were developing technologies that could send signals over phone lines, including stuff like modems, but A T and T wanted to restrict the network so that only products from A T and T itself would ever be allowed on their own phone infrastructure or even connect to the physical hand sets. You wouldn't be allowed to make a peripheral for a phone hand set because people, you know, individuals didn't own

those telephones A T and T did. This came to a head in nineteen fifty six when a case went to the d C Circuit Court of Appeals. It had already been decided in a lower Court got appealed, moved up to the Circuit of Appeals Court, and it was called Hush A Phone Corporation versus the United States. Now. The company hush a Phone produced a pretty simple product. It was meant to attach to the speaker side of

a phone hand set. So this is the part you would hold up to your ear with an old telephone, and this was a little cup that fit on the end of that speaker. It would cup over your ear. It was meant to provide some extra privacy because it it's like, you know, if you're whispering into someone's ears and you cut your hands around so that no one can hear you whisper. That's why it was called hush a phone. People wouldn't be able to suss out what

was going on if they were trying to eavesdrop. It also would help you hear what was being said more clearly. A T and T claimed that the Communications Act of ninety four gave A. T and T the authority to forbid the sale of these hush a Phone attachments. The company claimed that they could lead to a deterioration of phone service, and the first court agreed with them, but it got sent up to an appeals court and they said, what, No, attaching a cup to a speaker is not going to

deteriorate the entire phone service. That's not how the phone service works. If anything, it will affect one part of the phone service, and that is the person who's using the darn thing it is. This is not an issue. They struck it down, and this opened up the door to third party peripherals that could indirectly connect to the

phone company. They could not directly connect into the phone infrastructure, but it gave the opportunity to create something that could work in tandem with it, and it meant that other companies began to look into this. I'll explain how that developed a little bit more in just a second, but first let's take another quick break. A T and T s Bell Labs introduced the one oh three in the early nineteen sixties, and the one oh three modem had

a transmission speed of three hundred baud. That's three hundred bits per second. Not that speed, it would take you nearly eight hours to transfer a file that was one megabyte in size. Now, of course, most files of the time were significantly smaller than one megabyte. Even so, a single character, you know, a letter or a number or a symbol like you know, uh, an interaro bang or a dollar sign or anything like that. It would require

eight bits to encode. That's one byte, So a three hundred baud modem could send about thirty seven characters per second technically thirty seven and a half. But half a character's meaningless unless you're, you know, a big fan of the Twilight series or something. Meanwhile, a scientist named Robert veit Brecht was working on a technology to help deaf people communicate using telephone lines. Vite Brecht himself was born deaf, and his innovation used a device called an acoustic coupler.

And this was a third party periph role that a T and T would have likely shot down before that court decision made from a few years earlier, and that it totally weakened a T and T s case. The acoustic coupler was a special cradle that could hold a telephone handset. They gotta remember, a T and T owned all the telephones, so pretty much all the telephones were the exact same form factor, so it's really easy to

build a one size fits all peripheral. Because he knew what the phones were going to be like, So the handset would essentially go into two kind of rubber cups, and you would put the handsets speaker to go against the coupler's microphone, and the handsets microphone would go up against the coupler's speaker. Vipbrect hooked this up to a teletypewriter. It was an extension of the teletype idea I talked

about earlier. And here's how it worked. Now. Both of them have teletypewriter machines with acoustic couplers, So they each put their phones handset into those acoustic couplers, connecting the whole system together. Person one would type a message on their teletypewriter and that would then send a signal to the acoustic coupler, which would convert that signal into audio, and the audio would transfer over the phone line just

as that. What if they were having a voice conversation two person number two's handset, which is in you know, another acoustic coupler, The audio plays out over the handsets speaker. The acoustic coupler picks up that audio, converts it into another signal which goes to the teletypewriter and then prints the message. That person number one had originally typed. What made this invention more useful was the creation of teletypewriter

relay services. An entire language was even developed around it because communication could only go one way at a time, similar to using a walkie talkie or CB radio, So you have certain phrases that indicate when you are done speaking, you know, like with walkie talkies you might say over to indicate you're done. The acoustic coupler would allow for a wider adoption of modems and also allowed other companies besides A T and T, the opportunity to make modems themselves.

After all, the modems were not directly connecting into the phone networks. Nothing was getting plugged into the phone network itself. They were just sending audio signals over telephones, actual telephone handsets. They just happened to be a carrier signal for digital information as opposed to a voice telephone call. It was

a great work around. Now, if you've seen the classic nineteen eighties film War Games, which stars Matthew Broderick as a precocious hacker, you've seen an acoustic coupler because Broderick uses one and he puts his phone into his phone handset into an acoustic coupler when he hacks into systems

in that film. Over the years, companies made more advanced modems, but the customer base was still pretty limited in the sixties and seventies, because we have to remember it wasn't until the mid nineteen seventies that personal computers were even a thing so typically, so really we were talking about research facilities, a few companies, some gun or Mint, and some military offices, and mostly they were just talking to branches of themselves. They weren't cross talking because there wasn't

really a network set up yet. Some other important events that helped establish the foundation for modems include the creation of a standard called r S two thirty two. RS stands for Recommended Standard. This was another technology being developed around the same time as the evolution of modems, so

early nineteen sixties. It's a standard for serial communication for the transmission of information, and serial communication means that this method sends data one bit at a time in sequence, as opposed to parallel communication, in which you could send data in parallel channels all at the same time. By establishing a standard, companies didn't have to invent a new method for a computer to send data to some other device,

such as drumroll please a modem. By the time personal computers were coming around, the RS two thirty two standard was well established, and it was pretty typical to find at least one serial port on a PC. These could connect to things like modems, printers, computer mice, all sorts of stuff. Meanwhile, a group of scientists, with the backing of the U. S Department of Defense, were hard at

work creating a different set of standards. These standards would set the rules for how computers could send information across a network. You know, how would those messages take form, how would you do error correction? How would you make sure the entire message gets through? These rules would lead to the formation of the ARPA net, a sort of predecessor to the Internet, and then further go on to evolve into the rules that guide data transmission across the

Internet itself. On the telephone infrastructure front here in the United States, the government began to pass regulations on the industry, forcing A T and T to make concessions to consumers. Ultimately, later on the government would break A T. T up into several regional companies. Because of that monopoly, I talked about earlier and later most of these would just coalesced T one thousand like back into a T and T,

but that's a different story. One of those regulations, which was passed in the nineteen sixties had to do with the creation of the r J eleven connector also known as the phone jack. Earlier, phones were typically hardwired into houses with no jack at all. You couldn't disconnect the phone. It was wired directly into the wall. You couldn't plug anything else into the phone line because the other end of the phone line was inside the telephone. There was no access to it. But the r J eleven jack

meant you could do that. You could detach the wire from a phone and put it into something else, like a modem. Now, it was introduced in the nineteen sixties, but it wasn't until the US government passed regulations requiring their implementation in the mid nineteen seventies, so it took a decade before they were actually starting to really be

implemented on a widespread basis. Now you could build a device like a modem and plug a phone cable directly into the modem itself, rather than using an acoustic coupler to do this kind of halfway thing with the phone handset plugged into the coupler. This would also allow modem manufacturers to make faster modems with lower error rates. So all of this is happening, and by the time we get the early PCs, a lot of these technologies were

standardized and starting to mature. And that's a good thing because it meant that we as consumers weren't faced with tough choices that could come back to bite us. Now, imagine if we had to choose between different ways to connect to other computers and other peripherals. It would really limit the types of computers we could select, right, because whatever computer we select would determine what sort of peripherals we could use and what sort of other machines we

could communicate with. We wouldn't have just one Internet. We would have dozens of Internet all dependent upon their own proprietary hardware and their own proprietary protocols. It would be awful.

It would also be a lot like the early days of online service providers, where it was really typically pretty easy to communicate with other folks who were on that same osp but it was a lot harder or sometimes impossible to send messages to someone who was using a different online service provider, which was gross and yet another thing that was evolving around this time, where the various

data compression protocols. Compressing data became an important part, not just because of storage space, and it was so precious in those early days. I still remember when I thought two fifty megabytes of storage was going to be more than any person would ever need in their lifetime. It was also important because if you could compress data down so you were working with smaller file sizes, the transfers wouldn't take as long, which I guess is pretty self evident.

But all of these things had to happen to make computer communication practical for the average person. The first consumer modem that you could plug directly into a phone line without the need for a handset was the Haze smart modem, which first hit the market sometime in the late nineteen seventies early nineteen eighties. Until then, you were using acoustic couplers. But then very few folks in the world had a

computer in the first place. Even fewer of those had any need to connect their computer to some other computer, so it wasn't an enormous problem for most people. Other companies would follow Hayes's model and create similar modems, and they would compete with Hayes, and Hayes would just sort of hang on until the early nineteen nineties, and ultimately it would have to file for bankruptcy. But what about that sound I played at the beginning of this episode.

What is the sound of a dial up modem all about? Well, those sounds you hear, those tones you hear, and the noise you hear, they all represent a sequence that modems would go through in order to establish a connection, so that communication could actually happen between modems when you wanted to dial into a service, whether it was a bulletin board service, an online service provider, or later on an Internet service provider. Here's what generally happens with a dial

up modem. First, you hear the dial tone of the phone, followed by the sound of your modem dialing in whatever phone number you had programmed in for your service. You would then hear the phone ring and then pick up on the other end. You would then hear a cacophony of noises. But those noises established how the modem on your computer could communicate with the modem on the other end of the call. The earliest sounds, essentially are the

modems saying how fast they can go. I remember when I was a kid, we still had a pretty slow modem. At first. I think it was a baud, so two thousand, four hundred bits per second. Still not super fast. But this is the process of a modem saying, actually, this is how fast I can go. This is how much data I can send per second, how about you. The next sequence of sounds established the basic rules of data transfer,

including the sin ACT handshake. That's s Y N dash a c K. SINAC was that will send actually stands for synchronization, and it's all about synchronizing sequence numbers. Because even decades after that early work with the teletype, synchronization is still very important. Act stands for acknowledge. So a sin ACT handshake describes a sequence in which one modem initiates synchronization and the other modum says, yeah, I got you.

After that comes the actual rate negotiation segment. Earlier, the two modums said hey, this is how fast I can go. But this is where they say, here's how fast this transaction will go. Here's how quickly we will pass data to and from one another. Then we go to a sound that indicates that a connection has been established, that all the rules have been agreed upon, and the two modems are ready to communicate. And then the next sound you will hear as actual throughput, the actual data going

to the other machine. And then typically the external speaker on the modem will shut off and you won't hear the noise anymore. But anyone who picks up the phone on your line would hear the noise, and that would also really screw up your modem connection. I hate when that happened. That happened a lot when I was going on bulletin boards back when I was a kid. All of this communication still has to happen within that band of audio frequencies that make up the voice band on

the phone. Infrastructure technology is meant to improve phone communication. Stuff like echo cancelation and noise reduction would also end up helping modem technologies. Companies could boost data transfer speeds by making the modulation on that carrier wave more subtle and thus cram more bits per second transfers. So we saw bad rates go up. You know, it started off at like twelve hundred bad hundred hundred nine hundred fourteen point four kill a bits because I KILLO was a thousand,

soy point eight kill a bits. And then finally we hit fifty six K, the gold standard for dial up Internet. The birth of the Web drove a demand for modems, and the evolution of content on the Web meant that even if you had a fifty six K dial up modem, you were not getting data transfer speeds fast enough to really take advantage of what the Web was having to offer. That's when we started to see the rise of broadband

solutions like DSL and cable modems. But these weren't really modems at least not like the kind that performed the modulation and demodulation processes of dial up modems. See, the older modems were necessary because they had to convert that digital signal into an analog signal and then back again. But cable and DSL modems don't do that. They deal in digital. The data never has to transform to another format. So the modems are still necessary in order to facilitate communication,

but they're not translating. They're not actually doing modulation demodulation anymore, the way the dial up modems were, so really if you want to look at a modern technology that's closer to what dial up modems are like. You could think of WiFi as being that, because WiFi is all about taking digital information and encoding it into radio waves, broadcasting it out to a receiver, which then accepts those incoming radio waves and converts them back into digital information that

the computer can handle. These are closer to what the old dial up modems used to do, and there is a brief overview of dial up modems. Some people still use them, not very many, and they were an incredibly important technology for me as a kid. I'll never forget when I finally converted from dial up to k BOWL never had DSL, but I went to cable modems and uh yeah, that was a big, big jump. And one of these days I hope to have fiber. Hasn't happened yet.

My I s P doesn't offer it, and there's no other competing I s P in my neighborhood that offers it, so I'm stuck with cable, but still an improvement over a dial up. I hope you guys enjoyed this episode. Maybe you have a deeper understanding of how modems work and what their purposes, I hope. So, if you have any sort of suggestions for future episodes, maybe it's a technology or a company or person in tech. Maybe it's just a trend you would like me to cover, reach

out to me on Twitter or Facebook. It's the best way to get in touch with me, and the handle for both of those is tech Stuff H s W. I'll talk to you again really soon. Text Stuff is an I Heart Radio production. For more podcasts from my Heart Radio, visit the i heart Radio app Apple Podcasts wherever you listen to your favorite shows.