GC30-3004-4 IBM 3704 and 3705 Communications Controllers Principles of Operation
File No S360/S370-09

The complete text of the 3705 programming manual can be found here.  Some problems were encountered in creating a PDF so it is offered here in MS Word form with one file per chapter.

Zip file with all of the following chapters in MS word form

Download individual chapters

Chapter Zero: 
Includes Preface, Table of Contents, Abbreviations, Summary of Amendments

Chapter 1: Introduction
Provides a general description of the 3704/3705 and their functional units

Chapter 2: System Structure
Describes the registers, interrupt scheme, and levels
of the control program.

Chapter 3: Storage and Line Addressing
Describes the basic storage addressing procedure
and the format for addressing the individual communication lines.

Chapter 4: Instruction Set
Describes each of the 3704/3705 machine instructions with their format and condition codes

Chapter 5: Central Control Unit
    Describes the external registers which provide CCU functions such as console interface, error handling, CRC calculation, interrupt functions, diagnostics.

Chapter 6: Type 1 Communication Scanner
Describes entry level (interrupt on every bit) scanner

Chapter 7: Type 2 Communication Scanner
Describes medium performance (interrupt on every character) scanner.
Chapter 8: Type 3 Communication Scanner
Describes high performance DMA-based scanner for BSC and SDLC lines.
Chapter 9: Type 1 and Type 4 Channel Adapters
Describes simple channel attachment. 
Chapter 10: Type 2 and Type 3 Channel Adapters
Describes DMA-based channel attachment.
Chapter 11: Remote Communications Controller
Describes the hardware and programming required to support a communications controller at a remote location.

Appendix A-External Register Addresses 
Two page summary 
Appendix B-Input/Output Instruction Bit Definitions
Detailed description of bits in all input and output registers.
Appendix C - Input/Output Instruction Summary Charts

Glossary

