The internal hard disk drive has a storage capacity of 40 or 60 GB. The drive uses the Ultra ATA/66 interface. The internal hard disk drive uses the ATA5 protocol and is connected as device 0 (master) in an ATA Device 0/1 configuration.
The software that supports the internal hard disk is similar to that in previous Macintosh models with internal IDE drives and includes DMA support. To obtain information about that software and about the ANSI standard for the Ultra DMA IDE interface, see "ATA Interface".