Read Data Signal Timing; Disk Change Signal Timing - NEC FDl165 Product Description

RDT
(FM)
ROT
(MFM)
~+
-+- +-
~ w...-.-..
w
=
200
±
50 ns
T
=
2
IJS
T 1.5T 1.5T 2T
Figure 3-8 Read Data Signal Timing
3.4.7 Write Protect (PRT)
This line is high when the flexible disk does not have a
WRITE PROTECT notch and low if the disk has a notch. A
notch prevents writing.
3.4.8 Disk Change (DCG)
This signal goes low to signal the controller that the
flexible disk has been changed since the disk drive was last
selected. The time relationships are shown in Figure 3-9.
DOOR
I
DISK CHANGE
CLOSE
1~-O-PE-N--I_c_L_OS_E
_
DRIVE
SELECT <P
DISK
CHANGE <P
u
Figure 3-9 Disk Change Signal Timing
3-8