Following the release of the original Macintosh in 1984, Apple released the Macintosh 512K in 1985. The main difference between the two was the increase in RAM to 512 kB. The original Macintosh had 128 kB and started to be called the 128K after plans to release the 512K were revealed.

Just like the original Macintosh, the Macintosh 512K came originally with a 3.5” 400 kB floppy disk drive (at the time, most computers used 5.25” 360 kB floppy disk drives) and a 9-inch black-and-white video monitor with a resolution of 512 x 342 integrated on the computer’s body. The 512K was based on the Motorola 68000 microprocessor, which was one of the most powerful CPUs available at the time.

An upgrade version of the 512K with an 800 kB floppy disk drive was released in April 1986 and was called the 512Ke (for “Enhanced”). This model had the part number “M0001E”.