Surely many of you remember those old computers from the 80s and 90s, those with ivory boxes that had to be manually turned off with the button, and that many of them had a Turbo button and even a small display showing the MHz at which The processor worked. Today we are going to delve into the story to explain what exactly that Turbo button did, and why PCs today no longer use it.
The “culprit” of this Turbo button is none other than IBM, since it was they who implemented it the first time, and then other manufacturers copied (and in fact many cloned) the design, and surely you remember many mythical models that had it, like the 286 or the 486DX2 and 486DX4.
Curiously, we already told you that this button is not that it accelerated the system but that it did exactly the opposite, it reduced the speed of the processor when it was not pressed. In other words, if you had a 66 MHz 486DX2 processor, with the Turbo button pressed it worked at 66 MHz (which it should), but if we removed it it would work at only 33 MHz.
Next we are going to tell you the history of this button, why it was necessary to use it and why it stopped being used.
Why was that Turbo button created on old PCs?
The first IBM personal computer (IBM PC 5150) was released in August 1981 with the famous Intel 8086 processor running at 4.77 MHz. Competitors, like Compaq, soon reverse-engineered the machine, licensed the MS operating system -TWO from Microsoft and created their own computers “clone” of this IBM.
These clone machines often added features that the initial IBM machine did not have, and also at a much lower price. Some incorporated ports for integrated peripherals, more RAM and real-time clocks (the display that showed the MHz that we have spoken about before and that, in fact, you can see in the 286 that is seen in the photo above), at while retaining software compatibility.
Some of the early manufacturers of these clones took things much further and created much faster machines . For example, several models used this same 8086 processor but operating at 8 MHz, which was two or three times higher gross performance than the original IBM PC.
Of course, this speed increase was a problem, and is that most application developers in the early 80s could not anticipate that the IBM platform would become a platform compatible with previous versions, or that its performance would skyrocket. As a result, most software and game applications created for the IBM PC were specifically tuned for the 4.77 MHz clock speed of the 5150. If someone were to run these applications at a higher speed (such as the 8 MHz we have put in example), the programs became unstable and the games became hopelessly fast and therefore unplayable.
The first IBM PC CPU accelerator cards solved this problem by incorporating a physical switch on the back, allowing the machine to switch between full throttle speed and a 4.77 MHz compatibility mode . However, these were not yet known as “Turbo” modes, but marketing innovation was already around the corner.
Eagle Computer, the forerunner of the famous button
In July 1984, a PC clone maker called Eagle Computer introduced a new product line called Eagle PC Turbo . Each model incorporated an 8086 8 MHz processor and a new feature: a Turbo button on the front of the case that, when pressed, changed the processor’s operating frequency between 4.77 MHz and 8 MHz.
This at the time was sold as a marketing campaign, and in fact several media published articles saying things like ” The Eagle PC Turbo is so extremely fast that they have had to include a button on the front panel to stop it and thus increase its compatibility with will soften it. “
It is possible that other manufacturers used the term “Turbo button” before Eagle, but this brand was certainly the forerunner and the best known that used it. The word “turbo” is an abbreviation for “turbocharger,” which is what makes internal combustion engines faster. In the 1980s it was common for marketing departments to apply the word “turbo” to products to denote additional speed or power.
This was logical, since although what the Turbo button did was actually slow down the machine, nobody in their right mind would put a button labeled “slow down” on a PC they sell as very powerful, right?
A few years after the Eagle Turbo PC (in the era when PCs were already cheap enough to be sold almost in bulk), the word turbo suddenly became a generic term in the industry for this slowdown feature of the CPU, and in fact this has been inherited even today as you well know.
From the early to mid-1990s, the speed of CPU processors rose to never-before-seen heights. It went from 16 MHz to more than 100 Mhz, and this made the Turbo buttons become essential to be able to run certain software or games.
Why did this Turbo button disappear?
As we mentioned before, the need for this button was created by the software, which was designed for processors that worked at a specific speed. At a certain point, developers began writing applications with CPU speed increases in mind: these programs monitored the processor’s running speed and introduced a delay when necessary to keep the program running at the rate at which it was designed.
As those programs became more widespread and legacy software from the 1980s became obsolete, fewer and fewer people needed to use the Turbo buttons. Around the Pentium era (between the mid and late 90s), many PC towers stopped including them, and since it was a feature that in the end added costs to manufacturers, soon all manufacturers stopped doing so.
By the year 2000 the Turbo button had been completely extinguished, and if at some point someone needed to slow down their processor to run an old program, they had to use some specific software for it like CPUKILLER. The “Turbo” era was over.