The Dominant Topic
The computer has become the dominant force in the world and everything seems to be tied in with this ‘miracle’ invention in one way or the other. In this light, technological discussions and topics crop up every now and then, whether it’s at home with the kids or in a cafeteria when sharing a meal with colleagues.
From discussing the latest application (app) developed and all the wonderful things it can do, to second-guessing unthinkable innovations such as Google’s self-driving car, technology seems to have eclipsed all other topics especially among the young.
Kids are also getting swept into the technological wave and they also have their own questions and intrigues. Their little minds cannot yet grasp the full extent of this phenomenon and they usually grapple with a lot of queries. Recently, my ten year old son surprised me with a rather unexpected question: ‘Dad, how did computers remember stuff when you were young?’
Explaining the inexplicable
Considering that my listener was a ten year old, I had to come up with a simple yet enlightening approach to explain a seemingly inexplicable question. One thing that I admire about today’s kids, they have learnt how to use the many learning tools and resources at their disposal, which simplifies explanations a bit.
I decided to tackle this topic by explaining to the kid using analogies, using the human mind as an explanatory medium to explain the hardware components of computer memory. However, the kid quickly stopped me and explained that he knew the basics such as the hard dik and how it offered long term memory and the Random Access Memory (RAM) memory which offered short-term memory. The young kid explained that he wanted a lesson on the evolution of short-term computer memory and not the basics on computer remembrance. I welcomed the gesture and decided to take the high road if he so wished.
The evolution of RAM memory
I started the discussion on the evolution of RAM by taking back the kid to the 1940’s and 1950’s. The first generation computers in the 1940’s and 1950’s used vacuum tubes such as those in computer monitors for memory. The vacuum tubes had latches which could be used as registers or as drum memory which later become RAM memory. In the late 1950’s, transistors replaced the vacuum tubes and they also contained latches, which were a configuration of transistors which could store 1 bit of data.
The latches evolved into flip-flops which are packed together to form registers in modern day static memory. Instead of latches, transistors are also combined with capacitors to create smaller and more dynamic forms of memory. There are two types of short-term memory or RAM, Dynamic-RAM (DRAM) and Static-RAM (SRAM).
The SRAM is the fastest type of RAM in modern computers and it combines six CMOS transistors to make a flip-flop. On the other hand, the DRAM lines up a transistor with a capacitor to create a very compact memory cell.
The SRAM is very fast but also expensive, it is usually used in CPU registers and caches while the DRAM is dense and relatively cheap, it is usually used as the main memory in a computer. Hoping that this explanation helped ease the boy’s intrigues, I dug into his PC and physically showed him the parts I was referring to; by the end he seemed contented.