Specifications

PC/II+p Board Technical Reference Manual 45
MT002615 ©1999-2001, Megatel Computer Corporation
7.11.1 Floppy Disk Interface Pinout
Table 17 Signals – J904 – Floppy Disk Interface
PIN NAME PIN# SIGNAL NAME SIGNAL DESCRIPTION
F1-DENSL0#
e20 Density Select This signal Indicates whether a low (250/300 Kb/s) or
high (500/1000 Kb/s) data rate has been selected.
F1-DIR#
d21 Direction This active low output determines the direction of the
head movement (low = step-in, high = step-out).
During the write or read modes, this output is high.
F1-DKCHG#
a22 Disk Change This disk interface input indicates when the disk drive
door has been opened. This active-low signal is read
from bit D7 of address xx7h.
F1-DS0#
a20 Drive Select 0 Active low, output selects drive 0.
F1-DS1#
b20 Drive Select 1 Active low, output selects drive 1.
F1-HDSEL#
b22 Head Select This active low output determines which disk drive
head is active. Low = Head 0, high (open) = Head 1.
F1-INDEX#
d20 Index Status This active low Schmitt Trigger input signal senses
from the disk drive that the head is positioned over
the beginning of a track, as marked by an index hole.
F1-MTR0#
c20 Motor On 0 Active-low output selects motor drive 0.
F1-MTR1#
e21 Motor On 1 Active-low output selects motor drive 1.
F1-RDATA#
c22 Read Serial
Data
This active-low, raw data read signal from the disk is
connected here. Each falling edge represents a flux
transition of the encoded data.
F1-STEP#
c21 Step Head This active low output signal produces a pulse at a
software-programmable rate to move the head during
a seek operation.
F1-TRK0#
e22 Track 00 This active low Schmitt Trigger input signal senses
from the disk drive that the head is positioned over
the outermost track.
F1-WDATA#
b21 Write Serial
Data
This active low output is a write- precompensated
serial data to be written onto the selected disk drive.
Each falling edge causes a flux change on the
media.
F1-WGATE#
a21 Write Gate This active-low, high-drive output enables the write
circuitry of the selected disk drive. This signal
prevents glitches during power-up and power-down.
This prevents writing to the disk when power is
cycled.
F1-WP#
d22 Write Protected
Status
This active-low Schmitt Trigger input signal senses
from the disk drive that a disk is write-protected. Any
write command is ignored.