FDD Sensors
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1. DISK XHANGE SENSORS: - This sensors gives a signal to the tell the floppy controller, when a disk is ejected and a new one is inserted. 2. TRACK 00 SEBSOR: - It is also called home position sensor. A track 00 sensor provides a logical signal when the heads are positioned over track 00. Each time a read or write is ordered the head assembly is stepped to track 00. Although a drive remembers how many steps should be needed to position the heads over track 00, a carriage assembly position. If the drive steps to track 00 and there is no sensor signal to confirm the position. The drive assumes that a head positioning error has occurred. 3. INDEX HOLE SENSOR: - Spindle speed is critically important drive parameter. Once the disk has reached its current running velocity (300 or 360 Rpm.) the drive must maintain the velocity for duration of the disk access process. Unfortunately tilling that the spindle motor to move is no grantee that the motor is turning --- a sensor is required to masure the motor the motor speed. This is the index spindle speed in order to maintain a constant rotation. 4. WRITE PROJECT SENSOR: - Write protect sensor are used to detect the position of disk write protect tab.For 3.5” disk the write protect notch must be covered to allow both read and write operation. If the notch is open the disk can only read. Opt isolators are commonly used as write protect sensor’s since an open notch will easily allow light through, while a closed notch will cut off the light path. 5. DISK IN PLACE SEBSOR: - It detects the presence or absence or of a disk. Like the write protect sensor disk sensor are often mechanical switches that are activated by disk contact. If drive access is attempted without a disk in place the sensors causes the drive logic to induce a DOS ‘Disk Not Ready”- error code. 6. HIGH DENSITY SENSOR: - 3.5” drive must be able to differentiate whether the disk contains normal (Double) density for high-density media. A high- density sensor looks for the hole that is found near the top of all high density disks. A mechanical switch is typically used to detect the high-density hole, but a separate LED detect for pair may also be used. When the hole is absent (A dual-density disk) the switch is activated upon disk insertion. If the hole is present (A High-Density disk) the switch is not activated.
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Transcript of FDD Sensors
1. DISK XHANGE SENSORS: - This sensors gives a signal to the tell the floppy controller, when a disk is ejected and a new one is inserted. 2. TRACK 00 SEBSOR: - It is also called home position sensor. A track 00 sensor provides a logical signal when the heads are positioned over track 00. Each time a read or write is ordered the head assembly is stepped to track 00. Although a drive remembers how many steps should be needed to position the heads over track 00, a carriage assembly position. If the drive steps to track 00 and there is no sensor signal to confirm the position. The drive assumes that a head positioning error has occurred. 3. INDEX HOLE SENSOR: - Spindle speed is critically important drive parameter. Once the disk has reached its current running velocity (300 or 360 Rpm.) the drive must maintain the velocity for duration of the disk access process. Unfortunately tilling that the spindle motor to move is no grantee that the motor is turning --a sensor is required to masure the motor the motor speed. This is the index spindle speed in order to maintain a constant rotation. 4. WRITE PROJECT SENSOR: - Write protect sensor are used to detect the position of disk write protect tab.For 3.5 disk the write protect notch must be covered to allow both read and write operation. If the notch is open the disk can only read. Opt isolators are commonly used as write protect sensors since an open notch will easily allow light through, while a closed notch will cut off the light path. 5. DISK IN PLACE SEBSOR: - It detects the presence or absence or of a disk. Like the write protect sensor disk sensor are often mechanical switches that are activated by disk contact. If drive access is attempted without a disk in place the sensors causes the drive logic to induce a DOS Disk Not Ready- error code. 6. HIGH DENSITY SENSOR: - 3.5 drive must be able to differentiate whether the disk contains normal (Double) density for high-density media. A high- density sensor looks for the hole that is found near the top of all high density disks. A mechanical switch is typically used to detect the high-density hole, but a separate LED detect for pair may also be used. When the hole is absent (A dual-density disk) the switch is activated upon disk insertion. If the hole is present (A High-Density disk) the switch is not activated.
