It is sometimes hard to determine at which date new technology was invented. In case of the printing press it took centuries until it was used widespread. Surprisingly the birth of the internet can be localized in time very precisely It was a development which was realized overnight and all around the globe at the same time.
It is not clear why exactly the internet was developed in parallel but according to the computer history there was a time in the past in which the new technology was available suddenly. To understand the situation we have to describe two periods: the time before the year 1992 and the time after the year 1992. Before the year 1992, computers were available but they were slow, not standardized and very important they were missing of networks.
A typical example from 1990 was an Amiga 500 homecomputer which was used mainly for playing games. The Amiga 500 was missing of everything: it had not built in harddrive, the resolution of the monitor was low and the processor speed was only 7 mhz. The interesting fact is that compared to more professional devices like a Vax minicomputer sold for millions of US$ the Amiga 500 was advanced.
Let us take a closer look at so called professional computing before the year 1992. Most universities were equipped with a main frame computer. The system was used for batch processing and it was connected with other mainframes over a 9.6kbit telephone connection. Such a system wasn't used for practical application because the disk storage capacity was low, the bandwith was too slow and the price for such technology was too high. That means, even the university was equipped with the most advanced computer hardware nobody was using it.
At least, this is the description for the period until the year 1992. The interesting situation was, that the development to more powerful computer technolgy was realized within a small time frame. In the beginning of the 1990s, the former homecomputers were replaced by standardized PCs. A PC in the year 1992/1993 was cheaper and more powerful than the computers before. At the same time, the professional mainframes were replaced by local area networks which were running with workstations. These workstations were connected over fast ethernet cables and were able to display high resolution graphics. Also it should be mentioned that around the same year, the price for transmitting a single gigabyte of information over the telephone line has become cheaper.
Like i mentioned before this development doesn't take place over decades, but it was introduced very fast. That means on december 1991 the computer technology was very slow and only six months later the internet was available.
From a longer perspective the situation was more complex. until the pc industry was born it took many years. During the 1980s, PC hardware and software was developed. Also the development of workstations and fast internet routers took a long time. But, all the technology was available at one point in time which was 1992. After this time, the restrictions were solved. That means, the industry was able to deliver cheap and fast computers which can be used for practical applications. From a hardware perspective, a typical PC in 1992 was equipped with a 386sx processor. This allows the user to run basic applications like simple games, spreadsheet documents and even databases. In addition, such a PC is working well in a local area network and very important the technology has become affordable.
The interesting situation is, that before the year 1992 the computer industry was in a poor condition. Sure, some hardware was available for example home computers, and also software was written in Assembly and C. But it was not possible to use this technology in a meaningful way. For example to write a letter or to send an email. In that time, computer technology was something which was only available in imagine. What was shown in Science fiction movies was not a available in the reality.
Localizing the birth of the internet more precisely
The internet is a complex global computer system which was invented by many engineers. All the developments were united in a single year and into a single computer platform. It was exactly the year 1992 and the Intel 386SX PC which has made the internet possible.
Somebody may argue, that the internet was available in the 1980s already and that on a different hardware allows to connect to the internet as well. But a closer look will show, that only the combination of the year 1992 and the 386sx cpu has triggered the acceptance of a larger audience. It was some sort of sweet spot in which the technology was cheap enough and powerful enough at the same time so that the public went online.
Let us investigate some alternative hypothesis how the internet was born. Was it possible to use a home computer like the Commodore 64 to get access to the internet? no it wasn't possible because the homecomputers of the 1980s which includes 16bit machines like the Amiga 500 as well were not equipped with a hardrive and they wasn't capable of running even simple texteditors or telnet programs. Another interesting question is if mainframes from the 1980s were suitable for internet access. Technically it was possible to connect a supercomputer like the CM-2 with the internet. The problem was that this machine was very expensive. It was out of the reach for normal users. And the idea behind the internet is that not 10 or 100 users are geting access to online databases and e-mails but thousands and even millions. So the supercomputers of the 1980s were also not suitable for providing internet access.
Only the combination of a certain hardware performance, a cheap price and the availability of a network results into the well known internet. The year 1992 was the first year in history which combined all these elements. It can be interpreted as the year of birth of a complete new technology unknown before. The interesting fact is that the year after 1992 only little amount of improvement were available. Modern more advanced computers have improved the situation only in minor parts. That means, the difference between a text only webbrowser in 1992 and a text oly webbrowser in 2021 is small. A normal 386SX PC from that erea which is equipped with the lynx software plus an email program comes close to a more recent user's experience.
From a more pessimist standpoint the technology hasn't evolved that much from 1992. A simple isa network card from the past was able to provide 10 mbit connectivity. And this speed will serve today's Internet very well. What is known as the internet is unchanged since 30 years. It was improved only a minor parts. For example, the java language was invented, the h.264 videocodec has become available and wireless technology was added.
If the aim is to build some sort of prototype hardware which was able to act as a server and client as well, a standard desktop pc from the year 1992 works very well for this purpose. Even for today's requirements such a machine is more than capable of providing a technology known as the internet.
Let us summarize the specifications a bit: A 386sx pc is a 32bit processor which is faster than a 16bit processor. Also such hardware is sold for a low price so that a large amount of users can use the technology. In addition it is equipped with an ISA network card which is a standardized network for providing TCP/IP connectivity.
The interesting fact is, that before the year 1992 such computer technology wasn't available. It wasn't invented yet and therefor the internet was not available. What the computer users have done before the year 1992 was to use computers in a more specialized way. For example, an 8 bit homeomputer can be utlized to learn the BASIC programming language. While a pdp-11 like minicomputer can be utilized to create an UNIX operating system. What we know as the internet is the combination of all these elements into a single computer, sold for a low price.
[1] RetroTech Chris: Getting Started: Wireless Web Browsing in MS-DOS, 04.06.2020, youtube, https://www.youtube.com/watch?v=yH57bt-lU1Q