NEC FD1165 - Chapter 3 Interface Information; 3.1 Basic Operational Description

CHAPTER 3
INTERFACE INFORMATION
This chapter gives interface information for the Model
FDl165.
3.1 BASIC OPERATIONAL DESCRIPTION
When a
flexible disk is inserted into the Model FDl165 and
the door handle is closed, the collet presses into the
center hole of the flexible disk centering the disk and
clamping it in operating position on the spindle. At the
same time, this action switches the drive motor on. The
dr i ve motor moves the spindle tha t, in turn, rota tes the
flexible disk. Sensors in the disk drive detect the follow-
ing conditions.
• The flexible disk is inserted properly and the door
slot is closed.
• A single- or dual-sided flexible disk is loaded.
• The flexible disk has a write protect notch.
• The read/write head is located on the track 00 of the
flexible disk.
An index sensor provides a time reference by genera ting a
pulse for each rotation of the flexible disk. After the
flexible disk reaches 70% of its prescribed speed and the
Index pulse is detected four times, a Ready signal is sent
to the controller. The FDl165 is "ready" about 700 ms after
the door is closed.
After the disk drive receives a Step signal and a Direction
Select signal (see Sections 3.3.3 and 3.3.4), it energizes
the stepping motor, to move the read/wr i te heads to the
proper track. One of the two read/write heads is selected
by the Side Select signal. When the disk drive receives a
Head Load signal, the heads are loaded onto the flexible
disk by the head load cam. Once the head is loaded, the
disk drive reads from or writes to the disk when it receives
a Read Data or write Data signal from the controller.
3-1