Around the Corner

I was thinking about a test phase that we used years ago. The phase was, "The quick brown fox jumps over the lazy dog". It is a pangram, a phase that contains all 26 letters of the alphabet. They used it to test type writers and printing devices such as teletypes. Thinking about the phase caused me to think about teletypes.

I remembered when teletypes changed from clunking mechanical devices to slick machines. The change was the result of using “gated” logic circuits instead of gears and levers. A “gate” is a solid state chip that performs a specific simple function. Many gates had two inputs and one output. The most famous of these gates are “AND”, “OR”, “NOR” and “NOT”.  

Complicated logic chains can be formed by laying out hundreds of these gates. The new teletypes of the time used this scheme. Gates are “hardware” defined logic. Today our logic chains are all “software” defined.

I was thinking about the overnight demise of these teletypes despite their enhanced functionality. Their demise was a result of being caught with the advent of microprocessor technology. Computers could be programmed to also perform the teletype function using a modem [a device that turns an analog signal to digital and back again].

I wonder what other technological demises are just around the corner? Remember the “pager”?