FIC A360 Reference and, Справочное и сервисное руководство, Страница: 180 / 187

Pin Assignments
B.9 FDD Connector
The pin assignment for the FDD connector is as follows:
NO. Signal Description Type
24 RDATA#
Read disk data. Raw serial bit stream form the disk drive, low active.
Each falling edge represents a flux transition of the encoded data.
I
18 WGATE#
Write gate. This active low high current driver allows current to flow
through the write head .
It becomes active just prior to writing to the diskette.
O
16 WDATA#
Write data. This active low high current driver provides the encoded
data to the disk drive.
Each falling edge causes a flux transition on the media.
O
26 HDSEL#
Head select. The high current select the floppy disk side for reading or
writing. A logic “1” on the pin means side 0 will be accessed, while a
logic “0” means side 1 will be accessed.
O
12 DIR#
Direction control. This high current low active output determines the
direction of the head movement. A logic “1” on this pin means outward
motion , while a logic “0” means inward motion.
O
14 STEP#
Step pulse. The active low high current driver issues a low pules for
each track-to-track movement of the head.
O
6 DSKCHG#
Disk change. This input senses that the drive door is open or that the
diskette has possibly been changed since the last drive selection.
This input is inverted and read via bit 7 of I/O address 3F7H. The
DSKCHG# bit also depends upon the state of the Force Disk Change
bits in the Force FDD Status Change configuration register.
I
4 DS0# Drive select 0. Active low outputs select drives 0. O
10 MOTR0 Motor on. These active low output motor on. O
13 3MODE 3 Mode FDD select. O
22 WRTPRT#
Write protected. This active low Schmitt trigger input senses from the
disk drive that a disk is write protected.
I
20 TRK0#
Track 00. This active low Schmitt trigger input senses from the disk
drive that the head is positioned over the outermost track.
I
2 INDEX#
This active low Schmitt Trigger input senses from the disk drive that
head is positioned over the beginning of a track , as marked by an
index hole.
I
7,8,9 NC
25,23,21,
19,17,15
Gnd
Ground
I
11,5,3,1 +5Vs +5V power supply O
B.10 HDD Pin Assignment
The pin assignment of the internal HDD is as follows:
NO. Signal Description Type
1 HDDRESET# Reset primary disk O
35 RPDA0 Primary disk address 0 O
33 RPDA1 Primary disk address 1 O
36 RPDA2 Primary disk address 2 O
17 RPDD0 Primary disk data 0 I/O
15 RPDD1 Primary disk data 1 I/O
13 RPDD2 Primary disk data 2 I/O
11 RPDD3 Primary disk data 3 I/O
9 RPDD4 Primary disk data 4 I/O
7 RPDD5 Primary disk data 5 I/O
5 RPDD6 Primary disk data 6 I/O
3 RPDD7 Primary disk data 7 I/O
B-6 FIC A550 Service Manual