F81866A
the modem or data set has detected a data carrier.
GPIO54
DIR#
I/OOD14st, 5v
General Purpose IO.
Direction of the head step motor. An open drain
output.
OD14
,5v
Logic 1 = outward motion
13
14
3VCC
3VCC
Logic 0 = inward motion
Ring Indicator. An active low signal indicates that a
ring signal is being received from the modem or data
set.
RI6#
INst,5v
GPIO55
STEP#
I/OOD14st, 5v
General Purpose IO.
Step output pulses. This active low open drain output
produces a pulse to move the head to another track.
OD14
,5v
CTS6#
INst,5v
Clear To Send is the modem control input.
General Purpose IO.
GPIO56
I/OOD14st, 5v
Head select. This open drain output determines
which disk drive head is active.
HDSEL#
DTR6#
OD14
,5v
Logic 1 = side 0
15
3VCC
Logic 0 = side 1
UART Data Terminal Ready. An active low signal
informs the modem or data set that controller is
ready to communicate.
O14
GPIO57
I/OOD14st, 5v
General Purpose IO.
WGATE#
OD14
Write enable. An open drain output.
,5v
16
17
3VCC
3VCC
Data Set Ready. An active low signal indicates the
modem or data set is ready to establish a
communication link and transfer data to the UART.
General Purpose IO.
DSR6#
INst,5v
GPIO60
RDATA#
I/OOD12st, 5v
INst,5v
The read data input signal from the FDD.
Data Carrier Detect. An active low signal indicates
the modem or data set has detected a data carrier.
DCD5#
INst,5v
GPIO61
I/OOD12st, 5v
General Purpose IO.
Track 0. This Schmitt-triggered input from the disk
drive is active low when the head is positioned over
the outermost track.
TRK0#
INst,5v
18
3VCC
Ring Indicator. An active low signal indicates that a
ring signal is being received from the modem or data
set.
RI5#
INst,5v
I/OOD12st, 5v
INst,5v
GPIO62
INDEX#
General Purpose IO.
This Schmitt-triggered input from the disk drive is
active low when the head is positioned over the
beginning of a track marked by an index hole.
Clear To Send is the modem control input.
General Purpose IO.
19
20
3VCC
3VCC
CTS5#
INst,5v
GPIO63
I/OOD12st, 5v
Write protected. This active low Schmitt input from
the disk drive indicates that the diskette is
write-protected.
WPT#
INst,5v
19
Jan, 2012
V0. 12P