Canon A-200 series Service Manual page 79

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Pin Name
110
Desciption
¢
I
Input for 4MHz clock.
RESET
I
Makes the FDC idle and makes drive interface output
other than PSO, PS1 and WDATA LOW.
And makes INT and DRO outputs LOW.
CS
I
Makes RD, WR signals effective.
DB? -
-
WR
DBO
I/O
I
Bi-directional, 3-state data bus
Control signal for writing data to the FDC through the data
bus.
-
RD
I
Control signal for reading data from the FDC through the
data bus.
INT
0
This signal indicates that the FDC requires accessing and
is output at everyone byte in NON DMA mode, and at
the end of command in DMA mode.
AO
I
Selects status register or data register in the FDC ac­
cessed through the data bus.
DRO
0
Requests data transfer between the FDC and memory in
DMA mode.
DACK
I
This signal indicates that the DMA cycle is given. This acts
similar to the CS signal in the DMA cycle.
MFM
0
Determines an operation mode of the VFO circuit. MFM
mode when HIGH, FM mode, LOW.
SYNC
0
Determines an operation mode of the VFO circuit. Permits
reading when HIGH, inhibits, LOW.
RW/SEEK
0
Selects the functions of a signal used as both read/write
and seek. RW when LOW, SEEK when HIGH.
SIDE
0
Select head 0 or head 1 when dual-sided drive is used.
LOW for head 0, HIGH for head 1.
LCT/DIR
0
When RW/SEEK signal is in RW mode, this becomes LCT
and indicates that the W/R head of the drive is
selecti~g
more than 43 cylinders. When RW/SEEK is in SEEK, this
becomes DIR and determines a direction for seek.
LOW for inner direction, HIGH for outer.
FLTR/STEP
0
When RW/SEEK is in RW, this becomes FLTR and resets
FAULT status in the drive. When RW/SEEK is SEEK, be­
comes STEP and send a step signal for seek.
READY
I
Indicates that the drive is ready.
WPRT/2 SIDE
I
When RW/SEEK is in RW, this becomes WPRT and indi­
cates that the drive or media cannot be written data.
When RW/SEEK is SEEK, becomes 2 SIDE and indicates
that a double-sided media is inserted into the drive.
INDEX
I
Indicates a physical starting point on the track of the
media.
76

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