VT82C686B
Floppy Disk Interface
Signal Name
Pin # I/O Signal Description
D9
D6
E9
C8
B8
A8
D8
E8
D7
C7
E7
B6
A7
B7
C6
O
O
O
O
O
O
O
O
I
O
I
I
O
O
I
DRVDEN0
DRVDEN1
MTR0#
MTR1#
DS0#
DS1#
DIR#
STEP#
INDEX#
HDSEL#
TRK00#
RDATA#
WDATA#
WGATE#
DSKCHG#
Drive Density Select 0.
Drive Density Select 1.
Select motor on drive 0.
Select motor on drive 1
Motor Control 0.
Motor Control 1.
Select drive 0.
Select drive 1
Drive Select 0.
Drive Select 1.
Direction of head movement (0 = inward motion, 1 = outward motion)
Direction.
Low pulse for each track-to-track movement of the head.
Step.
Sense to detect that the head is positioned over the beginning of a track
Index.
Selects the side for R/W operations (0 = side 1, 1 = side 0)
Head Select.
Sense to detect that the head is positioned over track 0.
Track 0.
Raw serial bit stream from the drive for read operatrions.
Encoded data to the drive for write operations.
Signal to the drive to enable current flow in the write head.
Read Data.
Write Data.
Write Gate.
Disk Change.
Sense that the drive door is open or the diskette has been changed
since the last drive selection.
A6
G5
H3
I
I
I
Sense for detection that the diskette is write protected (causes write
Write Protect.
commands to be ignored)
WRTPRT#
/ DACK2#
Rx75[2] = 0.
FDCIRQ
/ USBOC0# / GPO25
/ DRQ2
FDC Interrupt Request.
Rx75[3] = 1.
FDC DMA Request.
FDCDRQ
/ USBOC1# / GPO24
/ SERIRQ
Revision 1.71 June 9, 2000
-15-
Pinouts
ETC [ ETC ]
