PCC D3400 - Page 6

TABLE OF CONTENTS (Continued)
Page
3.16.5 Cylinder Demand Address
(9 Lines) .......................... 3-15
3.16.6 Restore Initial Cylinder .................................... 3-15
3.16.7 Write Enable ............................................. 3-15
3.16.8 Erase Enable
............................................. 3-15
3.16.9 Write Data
Signal ......................................... 3-16
3.16.10 Read Enable .............................................. 3-16
3.16.11 Track Offset .............................................. 3-16
3.16.12 Activate Emergency Unload ... " ........................... 3-17
3.16.13 Start/Stop Disk Drive ...................................... 3-18
3.17 Interface Outputs (Disk Drive to Controller). . . . . . . . . . . . . . . . . . . . . . . . . .. 3-18
3.17.1 Ready ................................................... 3-18
3.17.2 Busy Seeking
(4 Lines) ..................................... 3-19
3.17.3
Sector Pulse ............................................. 3-19
3.17.4 Sector Cou nt Li nes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-20
3.17.5 Index Pulse .............................................. 3-21
3.17.6 Read Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-21
3.17.7 Read Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-21
3.17.8 Illegal Cylinder Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-21
3.17.9 File Protected ............................................ 3-22
3.17.10
Malfunction Detected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-22
3.17.11 Dual Platter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-23
3.17.12 Double Track Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-23
3.17 .13 Special Interface Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-23
SECTION IV - THEORY OF OPERATION
4.1 Introduction ..................................................... 4-1
4.2 Organization of the Disk Drive ...................................... 4-1
4.2.1 Main Chassis Group. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-1
4.2.2 Positioner Assembly ...................................... 4-4
4.2.3 Power
Supply Assembly ................................... 4-4
4.2.4 Read/Write, Servo, and Logic PCBAs ........................ 4-4
4.2.5 Temperature Compensation PCBA (200 tpi Models) .. . . . . . . . . .. 4-5
4.3 Functional Subsystems ........................................... 4-5
4.4 Positioner and Positioner Electronics ............................... 4-5
4.4.1 Positioner Assembly ...................................... 4-5
4.4.2 Positioner Electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 4-7
4.5 Read/WriteOperations
............................................ 4-10
4.6 Read/Write Electronics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-11
4.6.1 Head Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-11
4.6.2 Write Electronics ......................................... 4-11
4.6.3 Read Electronics .......................................... 4-13
4.7 Logic Functions and Control ....................................... 4-16
4.7.1 Logie Arrangement ........................................ 4-16
4.7.2 Disk Drive Functional Control ............................... 4-17
4.7.3 Spindle Speed Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-22
4.7.4 Position Control Logic
..................................... 4-25
4.7.5 Sector Electronics ........................................ 4-27
4.8 Motor Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-30
4.9 Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-31
4.10 Temperature Compensation (200 tpi) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-33
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