The Story of Information Technology Flashcards
(26 cards)
The slide rule
quick and convenient calculations. Scale was read by eye, level of judgement required for decimal places
Mathematical tables
Used before the introduction of accessible calculators. Filled with errors
Babbage
Aimed to alleviate the mental effort of calculation. Created a difference and analytical engine. Difference are strictly calculators whereas an analytical engine is a general purpose programmable engine. Neither of these were ever completed.
Marathon
Battle fought at marathon, human runner had to run to Athens to communicate news
Nollet
- Wanted to understand the speed of electrical conductivity. As far as he could measure, it was instantaneous
Semaphore
Visual signals given by flags or torches. Used in the military or navy when radio silence had to be maintained
The electrostatic telegraph
Salva, 1804. Better option than the optical telegraph
The chemical telegraph
Sommerring. Each letter had a wire, bubbles indicated which one. Impractical
Battery
Daniell. longest lasting battery at the time and key to advancing communications technology
Electric telegraph
Cook and Wheatstone. Could not send messages over a mile. Roget allowed them to send messages over longer distances. Only 20 letters could be included in this machine
Motivation for Morse
His wife died whilst he was away on business, he received news of her death after the funeral had occurred. Set about inventing the telegraph
Challenges in the telegraph
Appealed for funding, many did not vote due to fears of funding something they could not understand
Train station pickpockets and the telegraph
Reduced instances as now the news would get to the next station before the train could
Bretts
Laid the first ever underwater telegram lines. Fishermen destroyed the cable to sell the wire. The line across the channel was later completed by Crampton
Transatlantic telegram cable
Field brothers in 1858.
Curta
The first mechanical calculator that fit in the hand. Invented by Herzstark
ENIAC
electronic numerical integrator and computer. Eckert and Mauchly. Designed to compute tables. It weighed over 30 tones and required 2000 times as much energy as a modern laptop
Open source vs freeware
Open source has free access to the software and its source code, freeware provides access to just the software
History of opensource software
Free Software Foundation started in response to increasing privatisation of code. Was not well adopted and was followed by Open Source
Effects of open source on developers
Individuals are placed in a pool of skilled programmers and organisations can share the cost of developing common software across organisations
Effects of open source on consumers
Consumers participate in testing, negates the issue to tracking licensing, removes dependence on a single developer and allows for better security
Postgres
one of the first database management systems.
PostGIS
A feature of Postgres that allowed millisecond access to features in multi-million record spatial tables
GPS segments
space, control and user. Space is the satellites, control are ground units that track satellites, user is the network of machines that use it. Four different people accredited with its development
