AM3270/TR3271 Reference Manual

Contents
086705 Tandem Computers Incorporated vii
Details of the PRT Protocol 4-17
Message Format 4-18
Applicable File-System Procedures 4-18
CONTROL 1 Operation 4-19
WRITE Request 4-19
Error Handling 4-19
Details of the QUO Protocol 4-20
Communication With Quotron Devices 4-20
File-System Procedures 4-21
Section 5 A Closer Look at TR3271
Overview 5-1
Three TR3271 Modes 5-1
Examples 5-2
Subdevices 5-3
Configuration and Control of Emulated Subdevices 5-3
Level 4 Protocols 5-3
TR3271-Specific Operations 5-3
Implementation Caveats 5-4
Multiple-Address Versus Single-Address Lines 5-5
Priming Read 5-5
Read-Modified 5-7
Multiple-Block Transmissions 5-7
Obsolete Caveats 5-9
Summary of Applicable File-System Procedures 5-10
Read and Write Operations 5-10
TR3271 Product Environment 5-11
Using Multiple-Level Access Methods 5-11
I/O Interface Procedure (IOP) 5-12
Level 1 Protocol 5-12
Level 2 Protocol 5-13
Level 3 Protocol 5-13
Level 4 Protocol 5-14
Error Handling 5-15