Actual gambling machines have been around for over 115 years and have been popular ever since they were first invented. The first gambling machine was developed by Sittman and Pitt in 1891 in the Amercian city of Brooklyn. The symbols they used were playing card faces and payouts were based on poker hands. The 50 symbols were on 5 drums which would spin when a player placed a nickel in the machine and pulled the lever. The first machines did not pay out cash, instead the prizes would be goods from the bar that the machine was located and were based on how good the poker hand was.
An automatic payout system was not possible due to the wide range of poker hands that could produce a winning combination. Typically the Ten of Spades and the Jack of Hearts were removed from the drums to put the odds more in favour of the machine. These were key cards as they make an appearance in wider range of winning hands, e.g straights.

The first slot machine as we know it today was the, Liberty Bell which was developed by a Charles Frey in Amercian city San francisco in 1899. This new machine had 3 spinning reels which featured 5 symbols which were diamonds, hearts, spades, horseshes and a Liberty Bell. The machine was simplier and therefore enabled Fey to work out an automatic payout mechanism. If you hit 3 bells in a row on the payline that would win you the Jackpot prize of 10 nickels. If you won nothing it was termed "Jack".

Classic cherry and melon symbols come about from an early slot machine which had prizes of different flavoured chewing gums which has pictures of the flavours on the actual reels.
Another classic symbol, the BAR was the logo of the Bell Fruit Gum company.

The first electro-mechanical slot machine was developed by Bally Manufacturing in 1964 and was called Money Honey. This was the first machine in over 50 years that started to move on from Feys orginal invention. Internally the machine replaced springs and levers with electrical components and for the player the outward changes really added to the gaming experience with multiple coin play and higher jackpots. The use of the electricity allowed exciting slots noises and flashing lights. Overnight the slot machine had become a whole lot more exciting and appealing to alot more people.

Bally Manufacturing continued to lead the way in the development of slot machines and in the mid 1970's introduced a a Dollar Slot Machine which casinos arranged in carousels and bigger jackpots. Until now slots had been consider secondary gambling games for the casinos, with the table games considered primary profit games. This was now changing as the slots become increasingly popular.

In 1980 a new company called Sircoma produced a video poker slot machine. At first players were untrusting of the video aspect as they could not actually see the reels spinning. However they soon become very popular and still are today both in live casinos and online.

In the mid 1990s slot machines started accepting bills so players no longer needed to get change in coins to play, this meant more time at the slot machine and actually playing the slot even easier.

In 1992 Bally Gaming invented a slot machine which had multiple games for the player to choose to play from just the one machine.

In the late 1990s a slot machine was produced that introduced a bonus feature and another chance to win money aside from the spinning reels. Players would then then look forward to the next bonus round in the hope of winning the bonus jackpot.

Nowadays we are heading towards a cashless slots with the introduction of tickets or cards onto which cash can be placed the winnings. Some slots operate with touch screen technology and others have easy to use help menus.

The popularity of slots is exploding on the internet as software providers are coming out with new variations weekly for the casinos and many games now having amazing bonus game features which also offer great prizes. Many of these games are luck based, but proving popular are some skill based bonus games.

More and more people around the world are gaining access to high speed internet and at the same time access to online casinos who offer many online slot variations. Many of these players have never been to a real live casino, but can still enjoy the thrill of the spinning reels and hittinga winning combination.

Slots will no doubt be advancing and improving both in the live casino and particularly online for a quite a few years yet.