As the range of themes adopted by the manufacturers became ever wider, the fundamental mechanics of these old machines remained much the same for generations. While a lot of them had three reels, designs were evolved which meant that some slot gambling machines had four, five or even six reels in play. Images of these became synonymous with UK casinos.

There's without doubt that their popularity was due in no small measure to the hypnotic effect of the spinning wheels - which is why this formula is still one of the most popular forms of gambling today, among both punters as well as the machine companies. Many people mourn the passing of the old one-armed bandits, and their enduring popularity is shown in the idea that many old machines can fetch large sums on auction websites, and they are increasingly sought-after as collector's pieces.

The truth that the machines also involved some physical effort on the a part of the player also added to their appeal.