A computer is commonly defined today as a digital electronic machine that processes data according to a stored program (the Von Neumann architecture).
Like most well-to-do people in 1980s America, Marty McFly probably had a computer at home in his original time; the same is not true for the earlier time periods to which he traveled, and in the future period (2015) computing is much changed since.
1885
A few decades earlier, English inventor Charles Babbage had designed the first practical computer models, the Difference Engine and the Analytical Engine. American statistician Herman Hollerith also invented punched cards as a storage method for programmable devices (all mechanical, of course, just like the refrigerator Doc Brown built within contemporary technological limits) around this period. People who needed mathematical computations used logarithm tables (invented in the 17th century), slide rules (popularized by Amédée Mannheim a few decades before), pen-and-paper calculation or even mental arithmetic.
1955
"Computer" still generally means a person whose job is to compute, using one of the time-honored methods already mentioned (log table, slide rule and so on). The new data processing machines (or "electronic brains") occupied a few rooms all their own, and were so expensive to use that anyone who needed them for a computing task had to submit a program, written beforehand away from the computer, to the computer operator, and then wait a bit (sometimes even days) until given back the result of the program, hoping fervently no programming error had brought all the effort to nought.
1985
The Personal Computing Revolution begun a decade earlier (with the Altair 8800 and Apple II) was now in full bloom with computers for the home within reach of many families. Popular models were the Commodore 64, the Apple Macintosh, the IBM DOS PC and the newly arrived Amiga and Atari ST.
2015
In the novelization for Part II, computers were used to regulate the flow of flying vehicles on skyways with the aid of transponders, and for air traffic control to notify drivers of any violations of traffic law.
Whatever computers were still left from the 1980s were nostalgic curios, like the Apple Macintosh Marty McFly saw in a shop window. By 2015, computers with voice recognition and speech synthesis were commonly used in video simulcra and many household appliances, some with artificial intelligence wrote newspaper articles. Computers may also have been involved in trial, verdict and sentencing in data-courts.
However, computer networks had not developed any further than they had in the 1980s and were not used for communication; instead, information was exchanged through the telephone and fax system.
Real world
- As of 2010, Back to the Future: The Game is available to download on several computers, specifically the PC or the Mac.
Appearances
- Back to the Future Part II
- Back to the Future Part III
- Back to the Future Part II & III
- Back to the Future: The Animated Series