Maxtor 10K III manual Feature Descriptions

Feature Descriptions

If the block's data is unrecoverable, the block may or may not be replaced according to the state of the RUEE bit in the Maxtor Vendor Unique Page. If the RUEE bit is set, the bad data is relocated with a Bad Data Mark appended to it. If the PER bit is set in the Read-Write Recovery Page, operations resulting in bad block replacement activate Check

￿￿￿￿5%5+SCAM￿%10(+)74'&is a process of￿#761/#6+%#automatic ID assignment..;￿￿5%#/that eliminates￿the need for user involvement in the setting of unique SCSI IDs. The drives support and conform to the SCAM-2 automatic ID assignment protocol contained in the SCSI-3 draft standards for SCAM. The drives are also fully compatible with SCSI devices that do not comply with SCAM requirements.

￿￿￿￿5%5+6*'SCSI￿7￿+06'4(#%'.-34#provides￿￿￿￿CPFincreased￿￿7.64#performance￿￿￿￿.19and￿81versatility.6#)'to SCSI￿&+(('4'06+#disks. LVD uses.￿￿.lower8&￿￿ level voltage swings, differential signaling, and double transition (DT) clocking to allow a maximum bus speed of 160 or 320 MB/second in wide SCSI configurations.

The Maxtor Atlas 10K III disk drive supports the LVD/MSE (Multi-Mode LVD and Single-Ended) interface standard. When installed on a bus with only LVD devices the Maxtor Atlas 10K III disk drive operates in LVD mode at transfer rates up to 160 or 320 MB/second. It is fully compatible with Ultra2 LVD devices operating at slower transfer rates. If an Maxtor Atlas 10K III disk drive is installed on a bus with one or more single-ended (SE) devices, it automatically switches modes to operate in SE mode at the slower, legacy data rates.

Differential SCSI operation has the advantage of higher reliability of data transfer through increased immunity to electrical noise. Differential signaling uses a two-wire active system in which current from each wire flows in opposite directions and reverses direction for a signal transition. The direction of current flow determines whether the voltage levels on the two wires have a high/low or low/high relationship to each other. The common mode, or reference, level for the two LVD signals is +1.25 volts. High and low is defined relative to this level. LVD permits a wide range of signal amplitudes. The Maxtor Atlas 10K III interface drivers are designed to provide a high to low range on each signal of approximately 400 millivolts in a nominal configuration, resulting in a differential signal of approximately 800 millivolts.

Single-ended SCSI, in contrast, uses one-wire active signaling with the signal return wire connected to ground. The active signal range is switched between a high in the range of +2.4 - 3.0 volts and a low in the range of 0 - +.5 volts. LVD/MSE SCSI devices in single-ended mode do not have the signal return wires connected directly to ground, as these same pins must be driven to LVD levels when the device is operating in LVD mode. Instead, when in single-ended mode, the device turns on a driver transistor for each return line that acts as a switch to connect the signal return to ground.

Maxtor Atlas 10K III 6-9