Apple plans to release its next operating system, OS X Yosemite, this October. There could also be an appearance of a new 12-inch Retina MacBook Air and 4K desktop Mac.

According to sources of 9to5mac, Apple is currently finishing work on its next-generation of computers.

The MacBook Air should be a smaller 12-inch model, which may mean the 11-inch and 13-inch choices are ditched for this one size. In which case a Retina Display will be a welcome upgrade to the line. This may even be a middle ground between the Macbook Pro and Air meaning there is only one option – though we doubt that.

The desktop is also getting a resolution bump all the way up to 4K. Whether that's on iMac or Thunderbolt Displays isn't clear at this stage. But it will be Apple's first foray into 4K, potentially signalling it's move to create a high resolution Apple Television.

The higher resolution screens seem likely as Apple prepares to release OS X Yosemite which is made for high quality displays. It features more colourful icons, thinner text and sharper windows corners.

The unnamed source said: "Those interface elements appear especially optimized on higher-resolution screens, so it makes sense for us to debut new Retina Macs around the time of Yosemite’s release."

READ: Apple OS X Yosemite beta now available, here are 7 tips to get you started