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Slot machines have been entertaining players for over 100 years and have gone through many different transformations in their lifetime. From humble beginnings as simple three-reeled one-arm bandit machines that used to dispense gum and cigarettes, slot machines have grown to occupy the most casino floorspace and be the most played online casino game worldwide. What hasn’t changed is how popular slot machines are.

Early slot machines

The first slot machines were entirely mechanical, consisting of rotating gears around a central shaft. Pulling the lever pulls forward a cam and releases the reels to spin, and the cam resetting stops them one at a time. The clicking you hear is due to paddles hitting the reels and slowing them down. The reels are supported by discs with notches on – when these notches line up a pay-out is triggered. 

With so many moving parts, slot machines not only had the potential to break down regularly, but they could also be tampered with. Replacing the discs with different notches could see a pay-out on a non-winning spin and rearranging the symbols on the reels could change the likelihood of certain spins occurring.

20th Century changes

In 1963 the first electromagnetic slot machine was introduced. This saw the gears and cam replaced by motors and electromagnets. They also used buttons instead of levers as the arm was no longer needed to manually crank the internal system. It was the first step towards an automated system.

The idea of combining computer technology with slot machines first saw the light of day in 1976 with the introduction of the first ever video slot. The reels were gone altogether, replaced instead by a computer screen and logic boards to keep the results of each spin random. Video slots were a huge hit and quickly took over the casino floors. Rapidly improving computer graphics meant that video slots could include animations and movie clips which made them significantly more exciting to play.

Online slots

It was only twenty years later than online casinos really took off, and online slots quickly became the most popular games on offer. Most online review sites suggest that playing slots online is way more popular than real life slots or fruit machines in the pub. Because of the proliferation of video slots there were hundreds of ready-programmed games available and online casinos bought the rights to upload existing video slots onto their websites. This had a couple of advantages; first they could introduce new games quickly, and secondly, they could tap into legions of existing fans.

Nowadays there are dedicated studios who churn out dozens of new online slots every year and the demand from the public isn’t waning. The release of a new online slot can be as eagerly awaited as a new blockbuster movie, video game, or music album, and the popularity of these games looks set to increase over the next few years.

How online slots work

The most important technology behind each online slot is the Random Number Generator (RNG) software. This ensures that each spin is entirely random, not determined by what came before, not part of a planned sequence, and not beholden to a specific win ratio for pay-outs. It perfectly emulates the random results of the initial mechanical fruit machines, but the RNG also has another benefit – it is extremely difficult to hack, meaning online casinos that use RNGs have honest games.

The technology behind the RNG means that the exact composition of the symbols on each reel changes from game to game, but always according to a constant mathematical formula which sets their frequency and winning value. At the start of each game the computer generates 100 random numbers and the RNG translates that into which pictures appear on the screen. There are millions of combinations keeping each game fresh.

Audio-visual technology

It’s not just the way online slots work that relies on computer technology, the way they look and sound has also advanced greatly thanks to leaps in digital tech. The images on video slots in the 1970s were pixelated and simple, whereas now online slots are vibrant and animated. The most modern slots feature HTML5 designs which allow them to adapt to different screen sizes, perfect for playing on smartphones and mobile devices. This has been a huge benefit in the changing landscape of online casinos as more players are choosing to download apps and play on the go rather than logging in from their PCs at home.

In summary

The technology behind slot machines has changed a lot over the past 130+ years. From mechanical machines to digital entities, slots have retained their core look and play method but have adapted to increase their availability to players. Thanks to technology like RNG software, adaptive HTML5 programming, and sound and video cards, online slots bring all the fun of the casino slot machines right into our own homes.