IBM 4300 Manual page 186

Chapter 12. Input/Output Operations
Contents
Attachment of Input/Output Devices
12-2
Input/Output Devices 12-2
Control Units 12-2
Channels 12-3
Modes of Operation 12-3
Types of Channels 12-4
I/O-System Oper;;1,tion 12-5
Compatibility of Operation 12-6
Control of Input/Output Devices
Input/Output Device Addressing
States of the Input/Output System
12-7
12-7
12-8
Resetting of the Input/Output System 12-10
1/
O-System Reset 12-10
I/O Selective Reset 12-10
Effect of Reset on a Working Device 12-10
Reset Upon Malfunction 12-10
Condition Code 12-11
Instruction Formats 12-13
Instructions 12-14
CLEAR I/O 12-14
HALT DEVICE 12-16
HALT I/O 12-19
START I/O 12-21
START I/O FAST RELEASE 12-21
STORE CHANNEL ID 12-23
TEST CHANNEL 12-24
TEST I/O 12-25
Input/ Output-Instruction -Exception Handling
Execution of Input/Output Operations 12-27
Blocking of Data 12-28
Channel-Address Word 12-28
Channel-Command Word 12-28
Command'Code 12-29
Designation of Storage Area
Chaining 12-31
Data Chaining 12-32
Command Chaining 12-33
Skipping 12-34
Program-Controlled Interruption
Commands 12-35
Write 12-36
Read 12-36
Read Backward 12-36
Control
Sense
12-37
12-37
12-30
12-34
12-27
Transfer in Channel 12-39
Command Retry 12-39
Conclusion of Input/Output Operations 12-40
Types of Conclusion 12-40
Conclusion at Operation Initiation 12-40
Immediate Operations 12-41
Conclusion of Data Transfer 12-41
Termination by HALT I/O or HALT
DEVICE 12-42
Termination by CLEAR I/O 12-44
Termination Due to Equipment
Malfunction 12-44
Input/Output Interruptions 12-44
Interruption Conditions 12-44
Channel-Available Interruption
Priority of Interruptions 12-46
Interruption Action
Channel-Status Word
12-46
12-47
U nit Status 12-48
Attention 12-48
Status Modifier
Control-Unit End
12-48
12-48
Busy 12-49
Channel End 12-50
Device End 12-51
Unit Check 12-51
Unit Exception 12-52
Channel Status 12-52
Program-Controlled Interruption
Incorrect Length 12-53
Program Check 12-53
Protection Check 12-54
Channel-Data Check 12-54
Channel-Control Check
Interface-Control Check
Chaining Check 12-55
12-54
12-54
12-45
12-52
Contents
of
Channel-Status Word 12-55
Information Provided by Channel-Status
Word 12-55
Subchannel Key 12-56
CCW Address 12-56
Count 12-57
Status 12-57
Channel Logout 12-60
1/
O-Communication Area
12-60
Chapter 12. Input/OutputOperations 12-1