FIC a440 Servicehandbuch
Pin Assignments
FIC A440 Series Service Manual
B-9
43 FDD_WDATA#
88
ACIN
44 FDD_WGATE#
89
IDA#
45 FDD_TRK0#
90
TERR
92,94 +3VS
91 LID_SW#
B.1
B.1
B.1
B.12
22
2 Internal FDD Connector
Internal FDD Connector
Internal FDD Connector
Internal FDD Connector
The pin assignment for the FDD connector is as follows:
NO. Signal
Description
Type
3
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.
low active. Each falling edge represents a flux transition
of the encoded data.
I
9
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.
current to flow through the write head.
It becomes active just prior to writing to the diskette.
O
11
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.
the encoded data to the disk drive.
Each falling edge causes a flux transition on the media.
O
1
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.
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
15
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.
determines the direction of the head movement. A logic
“1” on this pin means outward motion, while a logic “0”
means inward motion.
O
13
STEP#
Step pulse. The active low high current driver issues a
low pulse for each track-to-track movement of the head.
low pulse for each track-to-track movement of the head.
O
21
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.
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
23
DS0#
Drive select 0. Active low outputs select drives 0.
O
17
MOTR0
Motor on. These active low output motor on.
O
14
3MODE
3 Mode FDD select.
O
5
WRTPRT#
Write protected. This active low Schmitt trigger input
senses from the disk drive that a disk is write protected.
senses from the disk drive that a disk is write protected.
I
7
TRK0#
Track 00. This active low Schmitt trigger input senses
from the disk drive that the head is positioned over the
outermost track.
from the disk drive that the head is positioned over the
outermost track.
I
25
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.
disk drive that head is positioned over the beginning of a
track , as marked by an index hole.
I
16 READY
FDD
ready
I
20 FDDIN#
FDD
insert
I
2,4,6,8,10,12 Gnd Ground
I
22,24,26
+5Vs
+5V power supply
O
18,19 NC
No
connection