Apple is introducing a new 13-inch MacBook Pro laptop that has a "Retina" display, with four times the resolution of the previous model.

The new model follows a 15-inch MacBook Pro with a Retina display introduced this summer, and will start at $1,699. Apple's marketing chief Phil Schiller said it will go on sale immediately.

The old MacBook Pro will still be sold, starting at $1,199.

The new model dispenses with an optical drive and a traditional hard drive. Instead, it uses solid-state "flash" memory. This makes it 20 percent thinner and at 3.75 pounds, nearly a pound lighter than the previous model.

Apple revealed the new computer at an event in San Jose, Calif., where it's also expected to reveal a smaller iPad.