Behold, the touchscreen Apple iMac that time forgot

There's been much debate and speculation about whether Apple will ever make a touchscreen Mac. While 2-in-1s, including Microsoft's Surface range, have grown in popularity, tablets and PCs remain two clearly distinct product categories for Apple.

However, you might be surprised to learn that touchscreen Macs did exist on the market all the way back in 1999. And they came in the form of the iconic iMac G3 with its translucent back (see our pick of the best Apple deals for the tech giant's current range).

In the video above, the vintage tech YouTuber Michael MJD takes us on a tour of an "extremely rare touchscreen Mac" prototype that he snapped up on eBay for around $1,200. The 17-minute video shows the device in action and explores its history. "While the rest of the world is anxiously debating whether we'll ever see a touchscreen Mac, I'm here to tell you there already was one over 20 years ago," MJD says.

But the touchscreen iMac G3 was not made or sold by Apple itself or targeted at consumers. It did reach the market but as a niche mod produced by a company called Elo under Apple's Value Added Reseller programme (there were also others produced by other companies).

Elo is very much still around today, producing touchscreen monitors and POS systems for customer service use, which is what the modified G3 was intended for. As the video points out, the G3's much-maligned hockey puck mouse would not have offered a great user experience for a customer service kiosk, but a touch screen could.

The ingenuity of Elo's approach compared to competitors is that it didn't use an overlay. It used transducers to transmit and receive surface acoustic waves to determine where the screen is being touched. A controller board was installed on the back of the neck board and plugged into the computer via USB. As well as preserving the display's image quality, the iTouch tech was also pressure sensitive (3D Touch years before the iPhone 6S, Michael says).

The product seems to have sold fairly widely, with YouTube users reporting having used them in schools and retail stores, but few seem to have survived. For some, the device's existence is a surprise, and many have commented on the ingenuity of the technology. "This is such a weird and innovative way to make a CRT into a touchscreen," one person wrote. "I knew of resistive and capacitive touchscreens, and also those early optical ones, but I never imagined you could make one this good with acoustics," someone else commented on the video.

It might seem strange that Apple, the company that produced the first commercially successful touchscreen phone, hasn't brought touch tech to its laptops. While the iPad Pro is more powerful than many laptops, some users have been calling for a touchscreen Apple device with a full desktop OS and perhaps a 360-degree display like some 2-in-1s. But on the other side, there are plenty of Mac users who hope Apple sticks to its product separation, fearing that a touchscreen would end up being rolled out to all MacBooks, increasing their price.

See below for the best prices on Apple's current Mac lineup. We also have a guide to the best MacBook Pro deals.