Track 00 (Tko); Dual-Sided (Tsd); Ready (Roy); File Unsafe (Fus) - NEC FD1165 Maintenance Manual

3.4.2 Track 00 (TKO)
When the read/write heads are on the zero (0) track on side
o
of the flexible disk, this signal goes Low.
3.4.3 Dual-Sided (TSD)
The TSD signal goes High if the flexible disk is
singl~­
sided: the signal goes Low if the flexible disk is dual-
sided. If there is no flexible disk inserted, TSD stays
High.
3.4.4 Ready (ROY)
The Ready signal goes Low 'when the Model FDl165 is ready for
use. The signal indicates that the following conditions
exist.
• Dc power is supplied.
• A flexible disk is inserted and the door is closed.
• The flexible disk has reached 70% of its prescribed
rotational speed and four lDX pulses have been gen-
erated.
• The flexible disk is single-sided and side 0 is de-
tected.
3.4.5 File Unsafe (FUS)
The File Unsafe signal goes Low when an alarm condi tion
occurs. The low FUS disables write operations and is reset
to High by a E'ile Unsafe Reset signal. The line goes Low
for any of the following conditions.
• The Write Data signal does not appear within 18
]J
s
after the Write Gate signal becomes active.
• The Wr i te Gate signal is acti ve but the Head Load
signal is not.
• The Write Gate signal is active but the Ready signal
is not.
• The Step signal is active at the same time that the
Write gate signal is active.
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