Invention of RAM
RAM evolved from a yet-older technology, called magnetic core or ferrite core memory and invented in the early 50s, which had in turn replaced old vacuum tubes. This magnetic core memory consisted of, well, a magnetic core, a small ring of a ferromagnetic ceramic whose magnetic polarity could be manipulated in one direction or another by a grid of wires laid over the top. This created the 1 or 0 of binary, by which all data is inevitably stored. By the mid 70s, almost all computers ran on these cores.
RAM was invented in the late 60s, and was not much of a conceptual leap from the magnetic core memory. Instead of magnetic rings, transistors were used to exactly the same ends to store data in binary. While this may seem like a minor technical change, it enabled the development of cheap, mass-produced semiconductors by IBM to the general market, and fueled the rise of mainstream computers.
Smaller Space, Bigger Size
From there, it was a race to fit more RAM in smaller spaces. The growth was exponential, and even today, it continues to do so. RAM technology, beginning in selling 64 byte devices, now functions in hundreds of millions of bytes just for your everyday computer. It is a staggering change over a very brief period of time, barely four decades ago, and since then, RAM technology has developed to the point of allowing incredibly complex computations on a scale that no human could even begin to calculate on their own.
Different Types of RAM
There are slightly different flavors of RAM, reflecting more nuanced roles that RAM can have. Dynamic RAM, or DRAM, requires periodic refreshment, and is the type found most commonly in computers. This is the original type of RAM. Static RAM, or SRAM, by contrast, does not need to be refreshed. Flash memory is technically considered to be is another type of RAM, and is used in many of today’s solid state drives.
The Future of RAM
Well, mostly, it just looks like to be more of the same for development of RAM: smaller sizes and more memory. The pace at which RAM has developed has been somewhat slower than the rate for other computing technologies—which granted sets an extremely high bar for development—has led to a discrepancy particularly with regards to the speed at which a CPU and RAM can operate respectively.
There are a few interesting twists, however. Some are attempting to develop a sort of non-volatile RAM, that is, RAM memory that will not be erased without constant power, and others are attempting to use magnetic plastics as a sort of throwback to magnetic core memory.
On the horizon, potential replacement technologies loom, just as RAM once did over magnetic core memory. Some are new, highly experimental variants on RAM, everything from quantum dots to carbon nanotubes, and others are like nothing we have seen before. What the future holds, however, is a good question.