PERSONAL COMPUTER HISTORY
In order to properly understand and appreciate the progress we have made and toanticipate the continued evolution of the industry, let's look at the progress of thecomputer. What precisely is a computer? Machines that helped people do computationhave been around for almost 150 years (Brigham Young invented a device to calculate thenumber of miles a wagon traveled by counting the number of wheel rotations). Therehave been all types of machines built to compute or measure various things (there’s evenone that will compute a logarithm).
Most of these machines are “analog” or value-based. So they can represent any value between zero to one equally as well as zero to a million. An example of an analog deviceis the odometer on your car (please note that these may not be true analog, but the concept still holds). Whether you move the car one inch vs. one thousand miles, it makes little difference—your car still retains the distance, thus further depreciating it’s value.There was another type of machine which used a magnet-powered switch which would close the switch when the electromagnet was turned on (this kind of switch is a “relay”).Telegraph used crude relays. The advantage of using switches (either “on” or “off”—called “digital”), the results would always be predictable (the value will always be zero orone). Analog devices always have to be tuned (just try to put a different sized tire on yourcar). The problem with relays is the power required and delay experienced was too greatto make them into a computational device. Early computers went a different route by using electron (or vacuum) tubes.Vacuum tubes have been used for power amplifiers, but they could also be used as switches as well and would function many times faster than the relays would. The idea was pretty simple: the tube had three plates.
The first plate was the source power, the second was the destination, and the third was the “switch.” The electrons would at the source would gather but would not be able to get to the destination unless power was applied to the “switch-plate.” Think of it like having scuffed your feet on the floor to generate static electricity then getting close to something (or someone) you want to zap—still they’re too far away. You need something to close the gap. That’s something likewhat the “switch plate” does.Memories and calculations were held and completed by turning on and off thousands of these switches.
Most of these machines are “analog” or value-based. So they can represent any value between zero to one equally as well as zero to a million. An example of an analog deviceis the odometer on your car (please note that these may not be true analog, but the concept still holds). Whether you move the car one inch vs. one thousand miles, it makes little difference—your car still retains the distance, thus further depreciating it’s value.There was another type of machine which used a magnet-powered switch which would close the switch when the electromagnet was turned on (this kind of switch is a “relay”).Telegraph used crude relays. The advantage of using switches (either “on” or “off”—called “digital”), the results would always be predictable (the value will always be zero orone). Analog devices always have to be tuned (just try to put a different sized tire on yourcar). The problem with relays is the power required and delay experienced was too greatto make them into a computational device. Early computers went a different route by using electron (or vacuum) tubes.Vacuum tubes have been used for power amplifiers, but they could also be used as switches as well and would function many times faster than the relays would. The idea was pretty simple: the tube had three plates.
The first plate was the source power, the second was the destination, and the third was the “switch.” The electrons would at the source would gather but would not be able to get to the destination unless power was applied to the “switch-plate.” Think of it like having scuffed your feet on the floor to generate static electricity then getting close to something (or someone) you want to zap—still they’re too far away. You need something to close the gap. That’s something likewhat the “switch plate” does.Memories and calculations were held and completed by turning on and off thousands of these switches.
