Internal ATA Hard Drives

**unlearnthetruth** · January 3rd, 2002, 03:16 AM

What exactly does having a drive's jumpers set to "slave" and "master" change? What do they mean?

**themacko** · January 3rd, 2002, 09:50 AM

Simply speaking, master and slave are how you set the order of which hard drive boots first. The drive that is set as the master is your main drive, the one that should have the OS on it. The slave drive is the secondary that should have apps and files. Thats really about it.

**edX** · January 3rd, 2002, 12:54 PM

of course with today's mac os's, both drives can have systems and you can switch the master/slave relationship as you please. This can be very useful at times, especially when doing diagnostics and repairs.

**i & i** · January 13th, 2002, 10:44 AM

"Slave", "Master" & "Single" have ABSOLUTELY NOTHING to do with the contents of the HD or what types of files are on it. Jumpers configure the device on the ATA chain. If the device has another device "downstream" (attached as slave). The first device is "Master" the second device is the "Slave". If there is only one device on that ATA bus it may have to be configured as "Single" or "Master". Different manufacturers use different terms/settings. If the jumpers are configured incorreectly the device will be unavailable and the computer may not boot.

These jumper settings are analogous to how SCSI device numbers & termination funtion for SCSI devices on a SCSI bus.

**DeltaMac** · January 13th, 2002, 03:28 PM

Yeah, the Mac doesn't care which HD is set to master, but two drives on the same BUS (same IDE cable) have to be jumpered different (One master, one slave). Most would recommend that the end drive be set to master, second connector from end would be slave. But I've reversed that with no problems in use. A lot of PeeCees won't boot to a HD set as slave, but Macs don't seem to care.

**DeltaMac** · January 13th, 2002, 03:36 PM

Yeah, the Mac doesn't care which HD is set to master, but two drives on the same BUS (same IDE cable) have to be jumpered different (One master, one slave). Most would recommend that the end drive be set to master, second connector from end would be slave. But I've reversed that with no problems in use. A lot of PeeCees won't boot to a HD set as slave, but Macs don't seem to care.