Table Of Contents - Xerox 7240 Reference Manual

CONTENTS
~--,
1.
GENERAL DESCRIPTION
1 . 4. OPERATIONS
30
Introduction Controls and Indicators
30
System Components Operating Instructi'ons
30
System Power Turn-On Procedure
30
2. FUNCTIONAL DESCRIPTION
3
Deck or Spindle Power Turn-On
-Procedure
32
Data Presenta
~ion
3
Power Turn-Off Procedure
34
System States 3
Disk Pack Installation
34
Operational States 3
Disk Pack
Remo~al
35
Unavailable Condition
3
Disk Drive/Pac* Inspection for Damage _ _ _ 35
0
Disk Pack
Clea~ing
36
Ready Condition 3
Disk Pack
Filte~
Replacement
Busy Condition 3
37
Mode 3
Disk Pack Usag$ Log
38
Transitions Between States
3
Recommended Do'sj and Don'ts for Disk Packs _ _ 38
I
Data Transfer
3
3.
PROGRAM INTERFACE
4
FIGURES
Disk Pack Organization 4
Model 7242 Disk Storage Unit v
Data Organization
4
1. Disk Pack Organization
5
Data Access
4
Error Detection 4
2.
Controlling/Disk Storage System Actions 14
Headers 4 3. Data In/Data Out Operations
15
Device Orders 4
Seek 6
4. Release Order 15
Sense 6 5. Restore Carriage Order
15
Write 7
Header Write 7
6.
Select Test Mode }>rder
15
Check-Write 7
7. Seek Order
16
Read 1 8
Read 2 8
8. Sense Order
17
Header Read 8
9. Header Write Order 18
Restore Carriage 8
Release 8
10. Header Read Order
19
Select Test Mode
9
11. Position Verification 20
Key Events
9
Start Input/Output
12. Write Order 21
9
Unusual End Conditions
9
13. Check-Write Order
22
Channel End Conditions 9
14. Read Orders 23
Transmission Error Conditions
10
Incorrect Length Conditions
10
15. Location of Disk Storage Unit Controls
Status Response
10
and
Indicator~
30
1/0
Instruction Status Bi ts
10
16. Operator Panel Ct:rntrols and Indicators 31
Device Status Byte
10
Programming Considerations
10
17. Filter Box Panel 33
Command Chaining
10
Controller Power Distribution Panel
18.
33
Interrupts
10
Sequence of Activity
10
19. Controller Power
~upply
Panel 33
1/0
Faults and Recovery Procedures
24
20. Logic Chassis Mai!ntenance Panel 33
I/O Interrupt Environment
24
Software Timeout Values
24 21. Power Supply
Pan~I
34
IOCD Flags
24
i
22. Disk Pack Installqtion/Removal 34
Additional Programming Considerations
24
1/0
Operation Evaluation
25
23. Disk Pack Load/Unload Mechanism 35
1/0
Fault Evaluation and
24. Disk Pack Filter 37
Recovery Procedures
25
Irrecoverable Errors
29
25. Disk Pack Filter Location 38
iii