The Power Macintosh G3 has a total of 5 locations, or bays, for storage devices. The two externally accessible bays in the front panel are designed for a ZIP drive and a CD-ROM drive. There are three internal locations on the bottom of the enclosure for hard drives. Power is supplied for all three drive bays, but only the startup drive has a data cable supplied.
The Power Macintosh G3 computer does not include a floppy drive.
Logic Board Drive Connectors
There is an Ultra DMA/33 (ATA-4) interface to support the startup drive only, and an ATA-3 interface for CD-ROM and Zip drives. The enclosure includes data and power connectors for the Ultra DMA/33 (ATA-4) startup drive, an optional internal ATAPI CD-ROM, or DVD-ROM drive, and an optional internal ATAPI ZIP drive.
Later revisions of the Power Macintosh G3 (Blue and White) provide support for dual IDE drives. They can be identified by the presence of a U bracket installed in the rear most drive bay which allows two hard drives to be mounted in that single bay.
The ATA-3 channel supports two ATA devices. The devices are configured in a ATA Device 0/1 configuration. The ATAPI CD or DVD-ROM, and Zip drive, when installed, occupy both device locations on the ATA-3 channel. The ATAPI CD or DVD-ROM, depending on which is installed, is Device 0 (master), and the Zip drive is Device 1 (slave).
The Ultra DMA/33 bus supports PIO Mode 4, DMA Mode 2, and Ultra DMA Mode 2 data transfers. The ATA-3 bus supports PIO Mode 4 and DMA Mode 2 data transfers.
Ultra DMA/33 Hard Drive
The logic board supports an internal hard drive that uses the standard Ultra DMA/33 (ATA-4) interface. The internal hard drive has a 40-pin connector and a separate 4-pin power connector. An 80-conductor high-density cable with a 40-pin connector is attached to the main logic board. A separate ground is provided on the 80-conductor cable for each of the signals on the 40 pin connector to provide improved signal quality. The power cable is attached directly to the power supply.
ATAPI CD-ROM Drive
The Power Macintosh G3 computer has a 24X-speed internal ATAPI CD-ROM drive. The CD-ROM drive supports the worldwide standards and specifications for CD-ROM and CD-digital audio discs described in the Sony/Philips Yellow Book and Red Book. The drive can read CD-ROM, CD-ROM XA, CD-I, and PhotoCD discs as well as play standard audio discs.
The CD-ROM drive has a sliding tray to hold the disc. The drive features a mechanism that supports 4X, 8X, 12X, and 24X data transfer rates and a data buffer that further enhances performance. The CD is configured as device 0 in an ATA Device 0/1 configuration.
Optional ATAPI Zip Drive
The Zip drive is an ATAPI drive and is connected as device 1 in an ATA Device 0/1 configuration on the ATA-3 channel of the main logic board.
Optional DVD-ROM Drive
The optional DVD-ROM drive is fully compatible with existing CD-ROM media. The drive supports CD-ROM at 32x speed maximum and DVD at 5x constant linear velocity (CLV). The DVD-ROM drive supports the following disc formats:
* DVD-ROM (One- or two-layer, one- or two-sided)
* CD-ROM (Modes 1 and 2), CD-ROM XA (Mode 2, Forms 1 and 2), CD-Audio, Photo CD, CD-RW, CD-R, CD-Extra
* CD-I (Mode 2, Forms 1 and 2), CD-I Ready, CD-I Bridge
* Video CD
Optional Ultra2 SCSI (LVD) Drive
An Ultra2 SCSI low-voltage differential (LVD) drive and Ultra2 SCSI PCI controller card are available as a configuration option. The Ultra2 SCSI interface provides data transfer rates of up to 80 MB per second.