The Macintosh IIx was introduced by Apple in 1988 as an incremental update of the original Macintosh II model. It replaced the Motorola 68020 processor of the II with a 16 MHz 68030 processor (running at the same clock speed), and the 800K floppy drive with the SuperDrive. The initial price of the IIx was $7,800 USD or $9,300 for a version with the 40MB hard disk drive. The IIx was the second of three Macintosh models to built in this case with the 6 NuBus slots; the last was the Macintosh IIfx.