IBM 6580 User Manual

FILE CONTROL CARD
The File Control Card, (Figure 7-15)
attached to the right side of each
diskette drive frame, contains cir-
cuits for the stepper motor, the head
load solenoid, and the read/write
functions. The card also contains the
amplifier circuits for the read/write
head and the LED/phototransistor
(PTX).
This card is controlled ~y signals
from the diskette adapter card,
located behind the diskette drive
unit. These signals and a description
of their functions are:
• Write Data. A signal on this line
causes current changes in the
read/write head, and data is writ-
ten on the diskette.
•
•
•
•
Inner Tracks. This signal
decreases write current on the
inner tracks because of the higher
bit density of these tracks. The
signal changes between track 42
and 43. On the type 2D drive, the
inner tracks signal is also used
to increase the read amplifier
gain from track 43 through track
76.
Write
Gate.
This signal activates
the write circuits.
Select Head
1. This signal
selects
head 1.
Erase Gate. This signal activates
the erase circuits to erase the
edges of the data track just writ-
ten and prevents reading across
tracks during read operations.
• Switch Filter. This line is
active at· tracks 62 and above and
is used during high density read
operations.
• Write/Erase Enable. This signal
is activated by the file control
card when the write or erase gate
signals' are sensed during a read
operation.
• File Data. This is a series of
clock and data pulses that repre-
sent the data read from the
diskette.
• Index. A signal on this line
indicates the beginning of a track
to the diskette adapter. It is a
1.5 to 3.0 milliseconds pulse that
occurs every revolution of the
diskette.
•
•
•
•
Diskette Sense. On the type 1
drive this signal is tied to
ground to always indicate a
diskette 1. On a type 2D drive,
this signal indicates a diskette
2D is being used. A diskette 1
does not activate this line.
Drive Present. This signal indi-
cates to the diskette adapter that
there is a drive unit present.
Access 0 and 1. The two acces
lines are activated in sequence to
cause the stepper motor to turn.
Head Engage. This signal operates
the head load solenoid and engages
the head load bail.
Chapter 7. Diskette Unit 7-15

IBM 6580 Specifications

General

Brand	IBM
Model	6580
Category	Desktop
Language	English