Obsolete tech 1: Communications

Rabbit was a telephone service that was launched in the UK in 1992. If you had a specially designed home phone handset, you could make outgoing calls whenever you were within 100 metres of a Rabbit transmitter. Initially limited to the city of Manchester, 12,000 base stations were rolled out nationwide.

The service lasted less than two years and failed due to the introduction of low-cost analog mobile phones that made and received calls.

Optical telegraphs were also known as semaphore telegraphs. They were invented in 1792 in France and relied on line of sight. France had 556 stations situated five to 20 kilometres apart which were used to transmit communication signals.  

The towers had moveable arms that represented letters of the alphabet. A trained telegrapher looked at the previous tower in the chain and copied the signals he received. He also looked at the next tower to check that the signal he sent was re-transmitted correctly.

The transmission of one symbol from Paris to Lille could happen in ten minutes — a speed of 1,380 kilometres per hour.

They were replaced by electric telegraphs in 1846.

Analog radio receives broadcasts that use amplitude modulation. The signal strength variation means that you have to move the aerial until the best sound quality is received by the receiver.

Although it has been mainly superseded by the introduction of digital radio for entertainment, analog radio is still used for long distance shortwave band communications between enthusiasts.

Dial-up internet access used switched telephone lines to access ISPs via a modem with its unique sound as it connected. It was useful as it required only a telephone line and a modem to make the call.

With a maximum speed of 56kbits/s it would be theoretically possible for a hiker carrying a 500Gb disk in a rucksack to transmit the data faster than a dial-up connection across the internet.

Although obsolete to many, three percent of Americans still use dial-up to keep in touch according to Pew Internet.

Palmtop computers, or personal digital assistants, have been around since the early 1980s when Psion released its "Organiser" device. Some PDAs had touchscreens, others had soft keys or keyboards for input. Handwriting recognition enabled pen input.

Now superseded by smartphones, tablets and watches.

Made almost obsolete due to the growth in numbers of mobile phones, the payphone is hardly ever used to make coin-operated calls.

Many phone booths have now been updated to accept calling cards and credit cards. Some booths are internet enabled to give you a quick fix if your cellphone reception is poor and you cannot find any wi-fi signal.

Pagers receive messages as beeps, tone alerts, voice messages and text. Initially launched in 1950 for doctors in the US, they are still occasionally used in hospitals and where reliability is paramount.

Not completely outclassed by cell phones, pagers are often used where radio transmitters cause issues in the locality. They are now used to call diners to their reserved tables in many restaurant chains.