Seek Complete
This line will go from a logic zero to a one when the R/W
heads have settled on the final track at the end of a seek.
Reading or writing should not be attempted when Seek
Complete is a logic zero.
Seek Complete must go inactive for any of the following
cases:
1 . A recalibration sequence is initiated (by drive logic) at
power on or after power failure because R/W heads are not
over track zero.
2. 12/usec (typical) after the leading edge of a step pulse or
series of step pulses.
3. The dc voltage fault portion of the write fault circuit is
activated.
Track 0
This interface signal indicates a logic one only when the drive’s
R/W heads are positioned at track zero (the outermost data
track). When the Track zero signal goes ‘true,’ it shall always
be ‘true’ prior to Seek Complete ‘true.’
Write Fault
This signal indicates that a condition exists at the drive that
will cause improper writing on the disk. When this line is a
logic one, further writing shall be inhibited at the drive until
the condition is corrected. It cannot be reset via the interface.
There are four conditions which will cause Write Fault to
be activated:
• Write current malfunction:
Write current in a head without Write Gate active
or
Write Gate and Drive Select active with no write current
in a head.
• A drive malfunction causing more than, or less than, one
head to be selected, or a malfunction causing a head to be
selected for read during write or for write during read.
• dc voltages are grossly out of tolerance.
• Write Gate and an inactive condition on Seek Complete.
2-30
To Next Page
Loading...