Fujitsu M2361A Customer Engineering Manual page 129

(5) System RTZ/Manual RTZ
In the System RTZ (SYSRZ) and Manual RTZ (MRTZL) modes, the head is moved
to cylinder 00 regardless of the position at which the head is currently
located. The System RTZ operation (SYSRZ) is started upon receipt of
Tag 3/Bit 6 (RTZ) from the controller when the drive is selected and is
not performing a seek or RTZ operation or when a seek error occurs. The
Manual RTZ operation (MRTZL) is started by the MRTZ swi tch on the display
panel when the drive is not performing the seek, RTZ, offset, or read/wri te
operation.
Figures 4.6.5 and 4.6.6 show how SYSRZ and MRTZL are started,
respectively. Figure 4.6.7 shows the sequence that is performed after
RZML is set high.
a.
State08(WaitState)
When the SYSRZ or the MRTZL operation is performed, ANYRZ is set
high.
Then, WAITL is set high, and the access mode latches (RZML, SRVL,
LNML, CNTL) and Seek Error (Access Check: ACCCK) are set low.
b. State 00 (Start RTZ)
When the SYSRZ operation is performed, the access mode latches are
set low and, then, WAITL is set low.
When the MRTZL operation is performed, WAITL is set high while SW2 is
high. When SW2 goes low, WAITL is set low.
c.
State 80 (Move In)
When WAITL is set low, STRZ and RZMJ, are set high.
Before the head detects Guard Band Patterns 1 and 2 (GBPl and GBP2) ,
the carriage is moved in the inner direction at the RTZ High Speed.
When the carriage passes cylinder 00 and GBPl is detected, Guard Band
Latch 1 is set high and the speed is reduced to the low speed.
If the head is on GBPl at the start of this state, the carriage is
moved at the low speed from the beginning.
d.
State 84 (Turn Around)
When the head passes GBPl and detects
CBP2,
CNTL is set high and, at
the same time, HVLST and
MVOTC
are set high. In this case, the head
is moved at the high speed in the outer direction.
e.
State86 (MoveOut)
Same as that of sequence RTZ.
f. State 06 (Rezero Linear Mode)
Same as that of sequence RTZ.
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