1270 Terminal Control Unit o Product Description Manual

2970.001

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March 1973 Edition

Memorex Corporation Santa Clara, California 95052

The information in this publication is subject to periodic revisions, and to updates by Publications Bulletins.

Requests for copies of Memorex publications should be made to your Memorex representative or to the Memorex branch office serving your locality.

A readers' comments form is provided at the back of this publication. If the form has been removed, comments may be addressed to the Memorex Corporation, Publications Dept., Santa Clara, California 95052.

©1973, MEMOREX CORPORATION

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PREFACE

The Memorex 1270 Terminal Control Unit is a functional replacement for the IBM 2701 DataAdapter Unit*, the IBM 2702/2703 Terminal Control Units, and the IBM 3704/3705 Communications Controller* in emulation mode. The 1270 enables users of IBM System 360/370 to interface with a variety of local or remote communications devices.

Th is publication contai ns reference information on the features a nd capabilities of the 1270, a hardware component description, operating environment for the controller, and detailed programming material. Early sections of the manual are recommended reading for management, programming, operations, and maintenance personnel.

The manual is divided into five sections:

• The introduction to the 1270 Terminal Control Unit highlights its advantages in the teleprocessing environment, and provides a general discussion of prominent hardware features available to the Memorex customer.

• A systems description is included for clear understanding of the major components of the 1270 hardware and the elements of the communications network. Features, prerequisites, and interface requirements have been provided to aid in the planning of the most efficient and capable customer installation.

• Section 3 provides the reader with basic principles of operation from a programming viewpoint. The Central Processing Unit and Terminal Control Unit are described in terms of physical level input/output commands.

• Asynchronous, or Start/Stop, communications are defined and discussed in depth. Operating modes, commands, terminal controls, and other details are presented for programming and other technical personnel. 1270 features are addressed atthe command level.

• Section 5 presents a full discussion of Binary Synchronous and Synchronous concepts and operations to the level required for technical personnel. Features and prerequisites are reamplified.

Appendices contain procedures, tables and other relevant reference material for the reader requiring in depth information for installion and enhancement of the Memorex 1270TCU. Ag lossary and index have been included as reader aids.

*Trade name for International Business Machines Corp.

A summary of many of the communications charts a nd tables found in this manual are available to the 1270 Terminal Control Unit user in the MemorexCommunications Data Reference Card, form number 2575.001. For comprehensive discussions of modems and the communications network in general, the following publications are recommended:

2979.001 Modems General Descriptions 2579.001 Modems Technical Descriptions

This publication supersedes:

804021 System Reference Manual 1270 Terminal Control Unit - May 1971

No # General Description Manual 1270 Terminal Control Unit - November 1970

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SECTION 1. INTR OOUCTIO N---------------------------------------------------------------------------1-1

ADVANTAGES OF THE MEMOREX 1270 ----------------------------------------------------------------1-2 FAC:ILITIES ----------------------------------------------------------------------------------------------------1-2 FLEX IB ILITY --- ----- ----- --- --- -- --- ------------- --- --- -- -- ------ --- -- ------ -- --- --- --- ---- --- -- -- -- ----- ---- --1 -2 DES IG N TECH NO LO GY -------- ---------------- -------------------------------- --- ----- -- -------------- ------1 -2 N E1WORK D lAG NOSTIC:S ---- ------------------------------------- ---------------- --- -- --------------------1 -2 ER R OR C:H ECK IN G ----- --- ----- -- --- ----------- --- ---- ------ --- -- --- --- --- -- --- --- ----- -- --- -- --------- -- --- -1 -3 FEA TU RE H IG H LlG H TS-------- ------------------------------------- ----------- --- ---------------------------1 -3

SECTION 2. SYSTEM OESCR IPTION -----------------------------------------------------------------2-1

G EN ERAL--- -------- --- -- - -- --- -- ----- --- ----- --- ----- ----- -- --------- ------ -- ----- --- --- -- ------ --- -- -- ----- --2-1 1/0 INTER FAC: E- ---- ----- -- ----- --- ----- --- -- --- ----- -- --- --- --- --- -- --- --- -- --- --- -- --- -- --- --- ------ -- -- ----2-1

C:hanne I Attachm ent C:onsider ations --------------------------------------------- --- -- --- -------- ------2-1 Restrictions - -- --- --- -- --- -- -- ------- -- -- --- ------ ----- -- -- ---- -- --- ----- --- --- -- --- --- ----- --- -- --- --- -- -2-1 I nsta II ation - --- ------- --- --- -- -- --- ------ --- ----- -- --- --- --- ----- --------- -- ----- --- -- --- ---- -- --- -- --- ---2-2

TERM INAL CONTRO L UNIT DESC:R IPTION ---------------------------------------------------------------2- 2 Major Components and Features----------------------------- --------------------- --- -------------------2-2

110 C:ontrol Secti on -- ----- --- ---- ---- ----- ------- ------ --- -- --- -- ---- -- ------ -- --- -- -- -- -- ------ -- ------ 2- 2 Alternate C:han nel Switch Feature ------------- -------- -------------------------------------- ------2-2

Term i na I C:ontrol Section ---------------- ----------- ----------------------------- ---------------- ------2-4 Au toca II Feature --- ----- -- - ----- --- -- --- ----------- -- --- ------ ----- ----- --- -- --- ----- -- ---- -- --- ------2-4 Au tospeed Feat ure - ---- -- ------ --- -- --- -- -------- ------- ----- ------- --- ----- -------- --- --- -- --- -- ----2-4 Autopad Feat ure -- ---- ----- -- --- --- -- --- -------- -- --- --- --- --- -- ------ -- ----------- --- -- --- -- --- ----- -2 -6 Station Select Feat ure - -------- --- -- --- ---------- ------- ----- ----- --- -- --- ----- ----- --- --- -- --- --- --- 2 -6

Assemb Ie ID isassem bl e Section - ---- --- -- ------ ---------- ---- ------- -------- --- ----- -------- ----- --- -2-8 Line I nte rface S ecti on - ------ ----- --- -- ----- --- ----- --- ----- - -- -- --- ------ ----- --- ------- - --- ---- --- --- -2 -8

Asynchronous Li ne Adapter -------------------------------- ----------------------------- -----------2-8 S ynch rona us Li ne Ada pte r ---- ----- --- ------------------- --- -- ----- ---------- ------ --- --- ----- -- --- -2-8 Wideba nd Li ne Adapter --- ----- --- -- ------ ----- --- ----- --- --- ----- --- ---------- ----- ----- ------ --- ---2-9 Asynch ronou s Li ne I nterfa ces ----- --- -- ------ -- ------------ --------------- --- ----- -- ---- -- --- --- ---2-9 Synch ronous Li ne I nterface----------------------------------------------------------- ------------ 2 -12

C:om mun ication F aci I iti es ----------------------------------------- ------- ---------------- ------ --------- 2 -13 TERMINAL C:ONTROL UNIT PLUGGING OPTIONS ---------------------------------------------------- 2-17

SECTION 3. OESCR I PTION OF OPERATION -------------------------------------------------------3-1

MU LTIPLEXER C:HANNEL 0 PERATIONS ------------------------------------------------------------------3-1 InputlO utput 0 per ati on ---- ----- ------ ------- --- --- --- --- -- --- -------- --- -- --- -- --- ----- - -- ----- ------ ---3-1

1/0 Initiation --------- ---- -- --- ---------- --- ----- ------ --- --------------- -- ---- -------- -- --- --- ----- -- --- -3-1 I 10 Term i natio n --- --- --- -- --- ---------- ----- --- --- --- ------- ---- ----- -- --- ---- ----- -- -- --- ----- --- -- --- -3-2

110 Instruction s------- --- ----- --- ---------- --- --- -- --------- ----- --- ----- -- --- --- -- --- --- -- ------ ----- --- -- -3-3 Sta rt 110 ----------- --- -- --- --- -------- -- --- --- -- ----- ------ -- ------ -------- -- ---- -- --- -- -- -- -- -- --- --- ---3-3 Halt 1/0 --------------------------------------------------------------------------------------------------3-4 Test 110 ------- --- -- -- --- --'- -- ----------- --- ----- ------ ----- --- ---- ---- ----- --- ----- --- ----- --- ----- -- ----3-4

C:ha n ne I Com m a nds- --- ----- -- --- -------- -------- ---- -- --- ---- -------------- ----- --- - -- -- --- --- ------- --- -3-4 C:om mun ication Li ne Addressing ---------------- -------------------------- ------------- --- --------------3-5 Address Assignment Considerations ----------- ------------- --------------------- ----- -----------------3-6

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1270 OPERATION S ------------------------------------------------- ----------- ------------- ------ -- --- ------3-6 Tra nsm it a nd Receive 0 perations --------- --------------------- ----------------------------------- ------3-8 Ope ra ti ng Modes ---- --- ----- -- --- -------- --- ------ ------------- -- ------ -- --- ----- ------- ------- -- -- --- --- -3-8

Mode 0 (Control Mode) --- ---- -- ------- --- -- ---- ---------- ------- ---- -- --- -- --- -- ------ -- --- -------- --- -3-8 Mode 1 (Text-O ut Mode) ----------------------- ------------------------ -- ------------- ----------- --- ---3-9 Mode 2 (Text-I n Mode) -------------------------------------- ------------------------------ -------------3-9 Mode 3 (Poll i ng Answer Back Mode)--- -------------------------------- ----- -------- ------ -- --- ------3-9

PROGRAMM ING CONSI DERATIONS ----------------------------------------------------------------------3-9 Autowrap --- ---------- -------- ---- --------- --------- ------------- -- -- ---- -- --- ----- ------ -- -- ---- --- ---- -- 3 -1 0

SECTION 4. ASYNCHRONOUS COMMUN ICATIONS --------------------------------------------4-1

DESCRIPTION OF ASYNCHRONOUS OPERATIONS-----------------------------------------------------4-1 Tra nsm it 0 peration -- --- -- --- --- -- -------- --- --- -- ----------- --- -- --- --- ----- --- -- ---- ---- --- ----- -------- -4-1 Rece ive 0 pe r ati on ---- ---------------- ---- --- -- --- -- ------------ ---- ---- -- --- --- ---- ------ -- ---- -- ---------4-1

COM MAN OS ----------- ------ ----- ----------- --- ----- -- --------- -- --- -- ---- -- --- --- -- ------- ---- --- -- ----- ----4-1 Tra nsm it-Type Comm ands------------------------ --------------------------------------- ------ ----- --- ---4-3

WR ITE ------ ------------ ---- ----- ------ -- --- ------------------- -- -- ------ --- --- ----- ----- -- ---- -- ------ ---4-3 BREAK - ----- --------------------- ------ -- --- ------------------- -- ------ -- --------- -- ----- --- --- --- ---- --- -4-3 WR ITE BREAK -------- -- --- -------- ----- --- ------ ---- --------- -- ------ -- -- ------ --- ----- -- ---- -------- -- -4-3 D IA GN OSTIC WRI TE --- --- --- ---------- --- ------------------- -- ------ -- --- -- --- --- --- -- -- --- --- ----- --- -4-3 WRAP-----------------------------------------------------------------------------------------------------4-4 PO LL _____________________________________________________________________________________________________ -4-4

DIAL-------------------------------------------------------------------------------------------------------4-5 Rece ive-Type Com m a nds ------ -- -------- --- ------------------- -- -- ---- -------- -- --- ----- -- ---- -- --- -- --- -4-5

READ -----------------------------------------------------------------------------------------------------4-5 READ CLEAR ---- -------- -- --------- ------- ------------------- -- --- ------- ------ --- ----- --- -- ---- -- -- --- -4-5 DIAG NOSTIC READ :--- --------------- -- --- ------------------- ------- ---- ------- -------- -- ---- -- --- -- --- -4-5 PR E PAR E -------------- ---------------- -- --- ------------------- -- -- ------- -- ------- ------ -- ---- -- --- --- ---4-6 INHIBIT ---------------------------------------------------------------------------------------------------4-6

Control Com m ands ---------- ----- ---- ---- --- ------------- -------- ------ --- ----- -- --- --- -- --- -- ------ -- ----4- 6 SET MOD E ---- -- ------ -- --- ----- ------ -- --- ------------------- ---- --- ---- ------- --- -- --- --- -- ----- ---- -- -4-6 ENAB LE ---------------- ---- --- ------ -- -- --- ---------------- --- -- -- --------- -------- ----- -- ---- -- --- --- -- -4-6 D ISAB LE- ------ --------- -- -- --- ------ -- ----- ------------- -------- ------ --- -- ----- --- --- -- ---- -- ----- -- ---- 4-7 S ENS E ---- -- ---------------- --------- -- -- -------------- --- ---- --- -------------- -- --- -- --- ------ ----- ----- -4-7 I/O NO -0 P ---- --------- -- -- --- -- ---- ---- --- ------------------ ---- ----- ----- --- ----- ----- -- --- --- ------ -- -4-7

Exception Comm ands ---------------- ---------------------------------------------------- -------------- ---4-7 SADZERO, SADONE, SADTWO, SADTHREE--------------------------------------------------------4-7

STATUS BYTE CO N DITION S ------------------------------------- ----------------------------- --------------4-7 In itia I Status Conditi ons ------------- ------- ------------ ---------------------------- ----- -----------------4-7 End ing Status Conditi ons--- -- ------ --- -- --- -- -------- --- --- -- ---- ------- --- -------- --- -- -- -- -- -- ------ -- -4-8

TERMINAL CONTROL STATUS BYTE CONDITIONS AND CAUSES -----------------------------------4-9 SENSE BYTE CONDITIONS ------------------------------------------------------------------------------- 4-13 TERM INAL CONTRO L FEATUR ES------------------------------------------------------------------------ 4-19

IBM Type I Term inal Control Feature ----------------------------------------------------------------- 4-19 Polli ng a nd Address ing--- --------- ---------------------------- ----------------------------------- ---- 4-1 9 Cha racter Recognition S u mm ary ------------------------------------------------------------------- 4-24

USASCII TERMINAL CONTROL FEATURE -------------------------------------------------------------- 4-25 Line Co ntrol- ---------- ----- -- ------- -- ----- ---------- ---- -- -- ------ ------ -- ----- --- ----- --- --- -- ------- 4-25

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Code Convert I Termi na I Control Feature ------------------- ------------- ---------------------------- 4-27 Code Convert I (READ Command) ------------------------------------------------------------------ 4-27 Code Convert I (PREPAR E Comm and) -------------------------------------------------------------- 4-27 Code Convert I (WRITE Command) ----------------------------------------------------------------- 4-27

Code Convert II Term i na I Contro I F eature---------------------- -------------------------------------. 4-32 PO II ing - ----- --- ----- --- ----- --- -- --- --- ---- --- --- -- --------- --- --- ------- ------ -- -- ---- ----- --- ----- ---. 4-3 2 Character-Recogniti on Sum mary -------------------------------------------------- ----------------. 4-32 Control Bits with Unique Functions ---------------------------------------------------------------- 4-36

USASCII CH ECKING TERM INAL CONTRO L FEATURE -----------------------------------------------. 4-36 IB M Type III Term i nal Control Feature --------- -------------- ----------------------------- -----------. 4-38

Line Control Characters -- ---------------------------------- ------------------------- ----------------- 4-38 Contro I Ch ar acter 0 escr iption ------ -- --- ---------- - ----- ----------- ----- -- --- --- ----- --- ----- -- - -- -- 4-3 9 Character Recogn iti on ---- -------------------------------- ---------------- --------- ---- -------- ------- 4-39

SECTION 5. BINARY SYNCHRONOUS COMMUNICATIONS-----------------------------------5-1

I NTROD U CTIO N --- ----- -- ---- -- -------- ----- --- -- --- ------ -- --- --- --- -- --- --- -- -- ------ --- -- ----- --- --- -- ----5-1 DESCRIPTION 0 F BSC 0 PERATIONS ---------------------------------------------------------------------5-1 DA TA- LIN K CON CEPT --------"--------------------------------------------------------- ----------------------5-2 DATA-LI NK CO NTRO L--------- ------------------------------------------------------------------- ----- --- ---5-2

Transmit Operations Using Data-Link Characters ----------------------------------------------------5-3 SYN Ch ar acters -- ----- ---- --- -------- ---------- --- -- ------ -- -------------- -- --- --- --- -- -- ---- -- --- -- -- --5-3 SOH and STX Char acters ------------------------------------------------ --------- --------------- ----- -5-3 ETB and ETX Characters ---- ------------- ---------------- ------------------------ ----- ----- ------ --- ---5-3 EOT, ACK, WACK, and NAK Characters -------------------------------------------------------------5-4 ITB Ch aracter ------ -------- -- --- ---- ---- --------- ---- --- --- --- ------- ---- -- ----- ------ ---- ---- -- ----- --- -5-4 OLE Ch a r acter ----- --- --- -- --- -- -------- --- ----- -------- ------ ---- ------ --- -- --- --- -------- ----- --- ----- -5-4 RV I Contro 1- --- ----- -------- ----- ------ ----- ------ ----- -- --- --- ---- ----- ---- --- -- -- ---- -- -- -- -- -- --- ------5-4 D LE -St ick Seq ue nce -- ---- --- ----- --- -- --- ----- - -- -- --- --- --- --- -- --- -- --- ---- ---- ------- --------- ---- --5-4 Pad Ch a racter -------- ----- -- ------ --- -- --- ----- ---- ----- -- --- -- - ---- --- ------ -- -- -- -- -- -- - -------- ------5-5 EN 0 Character ---- ------ -- --- -- ------ -- --- ----- ------ -- -- ---- -- -- ---- --- -- --- -- -- --- --- -- --------- -- - -- -5 -5

Receive Operations Usi ng Data -Li nk Ch aracters ----- ------ -------- -------- -------- -- --- --------------5-5 SYN Ch a racters - -- --- ----- --- -- ------ -- --- --- -- ---- ---- --- -- ---- -- --- --- -- --- -- ---- ---- -- ---- --.- -- -- --- -5- 5 SOH and STX Char acters - -- ------------- ------ ---------- ------------- --- ------------- -------- ---------5- 5 ETB and ETX Char acters - ----------- ----- ------------ --------------- ----- --- ---------- --- -------- ------5-5 ENO, ACK, and NAK Characters --------------------------------------------------------------------- 5-5 WACK ch ar acter -- --- ----- --- -- -- -- -- ---- ------ ---- ---- --- ----- ------ -- --- ----- --- ----- -------- --- ----- -5-6 RVI Cha racter ---- ---- ---- -- ----- -- -- -- -- --- ----- - ---- --- --- ----- ----- --- --- --- -- ----- --- ------ --- -- --- --- 5- 6 D LE Ch a racter --- -- -- ---- -- -- ------- -- -- --- -- --- - -- -- --- --- --- -- ----- --- --- -- --- --- --- -- ------ -- --- --- ---5-6 EOT Ch a racter --- -- -- -- ---- --- -- -- ---- -- --- -- ---- -- ----- --- -- --- -- --- ---- -- ----- --- ----- -------- --- --- --- 5-7 ITB Ch a racter - --- ---- --- --- --- --- --- -- -- -- --- ---- -- -- --- --- --- -- ----- --- - -- -- --- --- ----- ------ --- -- --- ---5-7 D LE -Sti ck Seq uence ---- -- -- ----- -- ---- -- --- -- -- -- -- --- --- ----- --- -- --- --- -- --- --- --- -- -- -- -- --- -- --- ---5-7

DESCRIPTION OF SYNCHRONOUS TERMINAL CONTROL OPERATIONS--------------------------- 5-8 Com mu n ication Code ------- ------------- ------------- ----------- ----------- ------------- ----------- ------5-8

Extended Binary Coded Decimal Interchange Code (EBCDIC) ------------------------------------5-8 United States of America Standard Code for Information Interchange (USASCII)----------- 5-10

Transpa rent Text Mode·- - - - ------------------------------------ ------------------- -- -------------- ---- 5 -10 Contro I Ch ar acters --- -- - -- ----- ---- -- -- --- ----- -- --- ------ -- - -- -- ---- --- ---- ------ -- --- -- -------- - -- -- 5 -10 Transpa rent- Read Operati on ---------------------- --------------------------- --- --- -- --------------- 5-1 2

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Transpa rent-Write Operation --------- --- ------------------- ---------- ---------------- ------ ----- --- - 5 -12 Transm ission -Code Checki ng - -- - - ---- ------------------------------ ----- --- ---------------- ---- ----- 5 -13

Vertical Redundancy Check (VRC) and Longitudinal Redundancy Check (LRC) -------------- 5-14 Cyclic Redundancy Check (CRC) -------------------------------------------------------------------- 5-14

BINARY SYNCHRONOUS COMMANDS----------------------------------------------------------------- 5-15 SET MOD E ---- --- --- -- --- --- -- -------- - -- -- --- ------- ------ --- -- --------- -- --- --- -- -- ---- -- --- --- -------- - 5 -1 5 ENAB LE - ---- -- --------- ---- --- -------- --- -- --- ----- -- ---- -- --- -- --- -- ---- -- --- --- -- -- ---- -- -- ---- -- --- ---- 5 -1 6 D ISAB LE - --- -- --- ----- ----- --- ----- ------ -- --- --- ------- ------ --- -- ------ -- --- -- --- -- ---- -- -- ---- -- -- - --- - 5 -1 6 PR EPAR E ----- -------- -------- ----- -------- --- ----- -- ------ --- -- --- ------ -- --- ----- --- -- --- --- ---- ---- --- - 5 -1 6 WR ITE -- -- -- -------- --- ---- -- -- --- -- ------ -- --- ~---------- -- --- -- --- ------ ----- ----- --- --- ----- ----- ------ - 5 -1 6 READ ------------------------------------------------------------------------------------------------------5-17 INH IB IT ---------------------------------------------------------------------------------------------------- 5-18 SEAR CH ----- ---------------- -- --- ------ -- -- --- ----- ----- --- --- -- --- ------ -- --- --- -- --- -- --- -- ---- -- --- -- -- 5 -1 8 ADDR ESS PREPAR E --------------------- ----------------- -- --- ------------------ --- -- --- ----------- ---- 5 ~ 18 POLL------------------------------------------------------------------------------------------------------- 5-1 9 DIAL - ----- --- -- ----------- --- -- --- ---------- --- ------------- --- -- --- -- ------ --- ---- -- -- --- -- ---- ------- -- -- 5 -20

EFFECT OF HALT 1/0 INSTRUCTION AND ZERO BYTE COUNT ------------------------------------- 5-20 SET MOD E-- --------------------- -------- ----- -------- -- ------ -- --------- ----- --- -- -- --- --- --- ----- --- --- - 5 -20 READ --------------------- --- -- ------------- --- -------- ---- -- ----- -- --- ----- --- --- -- --- --- -- --- -- --- --- ---- 5 -20 WR ITE ---- ---------------- ----- --- ------ ~------ -------- ----- --- --- ---------- --- ----- --- ----- -- -- -- -- --- --- - 5 -21 S EARC H -- --- ---------- --- ----- -- ----------- --- ----------- -- ------ ---------- --- ----- --- -- --- --- -- ------ -- -- 5 -21 PO LL- ----- -------- - -------- ---- --- ------ -- -- --- -------- -- ---- --- -- -- ----------- ----- ---- ---- --- -------- -- -- 5 -21 ENABLE, DISABLE, ADPREP, & PR EPARE ----------------------------------------------------------- 5-21 S ENS E -- -- ----- --- -------- ----- -- -- ----- ---- -------- ----- ------ -- --- --------- -- --- -- --- ----- ---- -- ----- --- - 5 -21 D IA L - --- ------- ----- --- --- -- --- ----- ---- ------------ ----- --- --- -- ----------- --- -- --- --- -- --- --- -------- -- -- 5 -21 WRAP ---- ----- --- ----- --- ----- --------- -- -- --- ---------- -- -- -- --- ------------- --- --- -- --- -- --- -------- -- -- 5 -22

HALT 1/0 INSTRU CTIO N ------------------------------------------------------ ------------------------ ---- 5- 22 SET MOD E------------ ------ -- --------- ------- -- ------ -- ------ ----- -------- --- --- -- --- --- -- ------ -- --- -- - - 5 -22 E NAB LE -- --- ----- --- -- ---- -- -- --- -- ---- -- -- --- -- --- --- -- ---- -- --- -- ----- ---- -- -- --- --- ----- --- ----- -- --- -- 5 -22 WR ITE - --- --- ------------ -- ---- ----- ---- -- -- --- -- --- --- ------ -- --- -- ----- ---- -- --- -- -- ------ -- ------ --- -- -- 5 -22 READ - ------- -- --- --- -- ------ -- --- -- ---- ---- -------- ----- --- --- -- --- -- ---- --- -'- --- -- --- --- -- ----- --- --- -- -- 5 -22 PH EPAR E -- --------- ------ ---- ----- ---- ---- --- -- --- --- ----- ---- -- -- ------ -- -- --- --- --- --- -- --- ----- --- -- -- 5 -22 AD PR EP - --- ------ --- -- ---- ---- --- ------ -- -- --- ----- --- -- ---- -- -- --- --- --- --- -- -- --- --- ----- -- --- --- -- - ---- 5 -23 SEAR C H ------ ---- --- -- -------- --- ------ ---- --- ----- -- ---- --- -- --- -- ------- ---- --- -- ----- -- ---- -- --- --- ---- 5 -23 PO LL- -------- -- --- ------------- ----- ---- ---- --- ----- --- --- -- --- ---- ---- ---- ---- -- --- ---- -- -- ---- -- -- --- -- - - 5 -23 o ISAB LE - --- -- --- ----- ------ -- --- -- ---- -- ----- -- ------ --- ----- --- -- -- --- ---- -- --- -- -- ------ -- ---- ----- -- - - 5 -23 S ENS E ---- -------- ----- -- ------ -- --- ---- -- -- -- --- --- --- -- ---- -- ----- --- --- ---- --- --- --- ----- -- -- ------- -- -- 5 -23 DIAL ----------- ----- --- ---- -- -- ----- ---- ---- --- ----- -------- - -- -- --- -- ---- -- --- -- --- --- -- --- ---- -- -- --- -- -- 5 -23

APPEN 0 IX A. ,1270 RO LLER IND ICATORS ------------------------------------------------------------- A-1

APPENDIX B. 1270 0 PERATOR CONTROLS ----------------------------------------------------------- B-1

APPENDIX C. 1270 PLUGG ING OPTIONS -------------------------------------------------------------- C-1 MODELS AT ELC 300 AND GREATER----------------------------------------------------------------- C-1 MODELS LESS THAN ELC 300 BUT GREATER THAN ELC 200 ----------------------------------- C-6 MO DELS LESS THAN E LC 200- ------ ---------- ---------------- ------ -- --- --- ------------------ --- --- -- C-8

APPEN DIX 0 . INSTALLATION REQU IREM ENTS ------------------------------------------------------- 0-1

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INSTALLATION R EOUI REM ENTS - DOM ESTIC------------------------------------------------------- D-1 INSTALLATION REOUI REM ENTS - 50 Hz COUNTRIES---------------------------------------------- D-3

APPENDIX E. HEXADECIMAL TO BINARY CONVERSION CHART ------------------------------------E-1

APPENDIX F. EIA INTER FACE CONN ECTO R PIN ASSIGNMENTS --"---------------------------------- F-1 r',. U APPENDIX G. G LOSSARY --------------------------------------------------------------------------------- G-1

INDEX---------------------------------------------------------------------------------------------------------- 1-1

TOTAL PAGES: 152

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SECTION 1.

INTRODUCTION

The Memorex 1270 Terminal Control Unit provides the IBM* System/3600r System/370 userwith a versatile interface to a wide range of communication terminals. The 1270 schedules and controls information flow between the relatively slow communication terminals and the relatively fast CPU (Central Processing Unit). Information flow between the 1270 and the terminals is directed and controlled over switched common-carrier, leased common-carrier, or equivalent privately-owned communications facilities. Figu re 1 -1 illustrates the types of devices that can be attached to the 1270.

The various models ofthe 1270 are identical in function, differing only in the features supported and in the number of communication lines available.

MULTIPLEXER CHANNEL

IBM SYSTEM/360 OR SYSTEM/370

MEMOREX 1270 TERMINAL CONTROL UNIT

Figure 1-1. Examples of Compatible Devices

*This is a tradename for International Business Machines Corp.

1 -1

ADVANTAGES OF THE MEMOREX 1270

The Memorex 1270 Terminal Control Unit offers substantial improvements in performance and capability in a single communications controller. Memorex offers its customers unique features and capability while maintaining functional compatibility with IBM programming systems.

FACILITIES

The Memorex 1270 controller is capable of operation in half- or full-duplex mode over two- or four-wire facilities for asynchronous and synchronous transmissions. Full duplex in the 1270 means that no delays occurfor I ine turnaround and thatdata will be transm itted or received in one direction at a time. Asynchronous transmission facilities may be voice grade and may be switched, leased, or privately owned. Synchronous transmission facilites a re supported via voice-grade andWideband line control.

In addition to the standard EIA interface (CCITT for European operations), as defined in RS -232C, Memorex offers a series of integral modems for use with the 1270. Modems may be either Memorex Integral Modems or external Western Electric Modems (or equivalent). Section 2 provides an in-depth discussion of customer modem requirements.

FLEXIBILITY

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A significant advantage of the 1270 Terminal Control U nit is the high degree of flexibility provided the (--", Memorex customer. Installation requ irements can be tailored from a vast number of configu ration "-._. possibilities and feature offerings.

The Memorex 1270 enables users of IBM System 360/370 to interfacewith a broad range of local and remote communications devices using synchronous mode for high-speed devices which follow established IBM Binary Synchronous Communication (BSC) conventions at speeds up to 50,000 bits per second, and asynchronous mode for low-speed transmissions at line speeds which range from 110 bps to 1,200 bps (Table 1-1). The 1270 Terminal Control Unit recognizes and translates a wide variety of transmission codes including USASCII, Correspondence, PTTC, and BCD in Asynchronous mode, and EBCDIC and USASCII in BSC mode. BSC code independence via Synchronous Transparency is available.

DESIGN TECHNOLOGY

Advanced circuit technology allows Memorex to offer the user a high degree of reliability. Functional packaging and modular design result in an extremely compact, versatile device that can be field reconfigured with a minimal impact on user operations.

NETWORK DIAGNOSTICS

Memorex has developed diagnostic programs to aid in the timely isolation a nd correction of potential problems. Troubleshooting and preventive maintenance can be performed through unitfunctional test programs. The user is provided with detailed on-line monitoring and diagnostic capability through extensive control and indicator test panel functions (see Appendix B). The standard a utomatic wraparound (Autowrap) feature can be used to further isolate comm unication problems. Autowrap is discussed in detail at the end of Section 3.

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TABLE 1-1. LINE SPEEDS AND CODES

Transmission Code Mode Bits Per Second (Baud)

USASCII Asynchronous 110 to

1,200

BCD/PTTC Asynchronous 134.5 or or

BCD/Correspondence 600

USASCII Asynchronous up to (2260/2265) 9,600

USASCllorUSASCIl Synchronous up to with Transparency 9,600

EBCDIC or EBCDIC Synchronous up to with Transparency (Wideband) 50,000

ERROR CHECKING

Error checking conventions are compatible with IBM conventions for asynchronous and Binary Synchronous Communication modes. Asynchronous USASCII LRC (Longitudinal Redundancy Checking) is available as a special option. Parity checking can be even, odd, or notchecked at all, at the user's option. Error status information is available to the user.

FEATURE HIGHLIGHTS

Memorex has developed a single communication controller that provides its customers with a number of desirable and unique features. Highlights described herein, are amplified in a more technical manner elsewhere in this manual.

Line Expansion

The 1270 Terminal Control Unit is capable of supporting from 1 to 96 communications lines th rough line expansion offerings.

Alternate Channel Switch

This feature permits the 1270 to be manually switched between the multiplexer channels of two separate IBM System 360/370 processors. The 1270can be attached toonlyone processor ata time.

Automatic Line Connections (Autocall)

On switched (dial) networks, calls can be answered or initiated automatically. Autoanswer allows the 1270 to answer incoming calls under user program control.

1-3

The Autocall Feature allows the 1270 to initiate calls under userprogram control. Autocall is available on a Touch-Tone* or rotary network via the use of:

1. a Western Electric 801 C with a Western Electric modem,

2. an Autocall adapter with a different modem (non-Western Electric),

3. an MRX Autocall modem.

The Autocall feature is only available with 60 Hz models (domestic and Canada).

Station Selection

The 1270 with BSC capabilities may be used on a multipoint network as a tributary (remote) station. The basic BSC-equipped 1270 is designed to operate as a Control Station on a point-to-point or multipoint basis. However, with the installation oftheStation Selection feature, a BSC-equipped 1270 can be used as the tributary station.

Automatic Speed Recognition (Autospeed)

The Autospeed feature allows a variety of asynchronous dial-up terminals of different speeds (11 0 - ~~ 1200 bps), using BCD or USASCII communication code, to share the same Line Interfaces and ~ modems on the 1270. Autospeed can be used effectively to optimize the usage of available line and --modem facilities, thus reducing the user's overall operation costs.

Dual Speed

Dual Speed is a unique 1270 feature designed for exclusive use with Memorex modems. When installed with a 1222-2A Integral Modem, the 1270 a IIows two-way a Iternate data transm ission by way of the reverse channel, thereby eliminating line turnaround.

Automatic Polling (Autopoll)

The 1270 reduces CPU interference (overhead) during POLL operations in a multipoint (multidrop) environ ment.

Autopad

The Autopad feature com pensates for unique timing characteristics in the Memorex 1240, 1250 and and 1280 terminals, so that the enhanced capability of these terminals can be utilized without programming changes. Lines can be dedicated to Autopad or selected under program control.

*This is a tradename of Western Electric Corporation.

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Line Adapters Line adapters serve as the interface between the communications lines and the 1270. These units o provide bit buffering.

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• Asynchronous Adapters each support up to four asynchronous lines at speeds which range to 1,200 bits per second. With the Autospeed feature, it is possible to mix various speeds and codes on the same adapter.

• Synchronous Adapters each support up to four binary synchronous lines at speeds which range to 9,600 bits per second. Lines of varying speeds on one line adapter are possible through modem speed differences.

• Wideband Synchronous Adapters permit the attachment of wideband lines to support synchronous transmission speeds of up to 50,000 bits per second. The IBM BSC-Synchronous Terminal Control feature is required for wideband adapter use.

Line Interfaces Line interfaces provide cabling and, in certain applications, modem functions required in attaching the 1270 to a communications network. There are several types of I ine interfaces, including both synchronous and asynchronous types .

• Autocall Adapters are used for interfacing to non-Bell System modems with the auto-dial capability on synchronous lines.

• 801 Autocall Adapters are used for interfacing to a Bell System 801 C2 or 801 C4 autocall unit via Touch-Tone facilities. Operating speeds are constrained to the normal dialing rate of the 1270 Autocall feature, which is required. Available with asynchronous, synchronous, and Wideband lines.

E IP. Interface

This feature allows the 1270 to attach to Western Electric external modems(or equ iva lent). The signal designators and pin assignments of the interface with common-carrier data sets (asynchronous or synchronous) conform to EIA Recommended Standards 232C (EIA RS232B).

Modems

Modems are an essential part of any data communications network. Memorex offers a variety of modem equipment which can replace many Western Electric and IBM modems. Memorex Integral modems include:

1220 models - 103 compatible with full-duplex capability

1221 models - IBM TYPE I compatible Limited Distance Adapters

1222 Dual Speed - a unique Memorex offering

. 1-5

Terminal Control Features

The terminal control features available on the 1270 Terminal Control Unit provide communications services including bit assembly and disassembly according to unique terminal code, mode of transmission, timing considerations, control character recognition and error checking.

Up to four Asynchronous plus one Synchronous Terminal Controls may be specified in any combination. To satisfy customer requirements, the 1270 is designed to accept more than one terminal control of the same type. Tables 1-2 and 1-3 should be referenced for specific terminal devices supported by the 1270 for the following control types:

• USASCII - an asynchronous terminal control feature that provides control and validation services for supported USASCII devices such as Memorex 1240, 1250, and 1280 Communications Terminals; and Models 33 and 35 Teletype.* Odd, even, and no parity checking are supported.

• Code Convert la, Ib - these two terminal control features allow the high performance Memorex 1240 and 1280. Communication Terminals to be software compatible with the IBM 2741 type of terminal. Code Convert la translates incoming USASCII generated code into the BCD/PTTC code set and the reverse for outgoing data. Code Convert Ib provides the same kind of conversion for IBM BCD/Correspondence code. The 1 270Autopad feature is requ ired with Code Convert I (see Autopad).

• Code Convert II - a Memorex Communication Terminal Control feature wh ich offers software compatibility between the Memo'rex 1280 and IBM 2740-1 terminals, as well as the r~ Memorex 1242 and IBM 2740-2 terminals. USASCII code is translated to the BCD code set ~/ and vice-versa. LRC checking is standard with Code Convert II.

• USASCII Checking - this feature provides all of the function and capability of the standard USASCII control described above,. plus LRC checking. The feature is designed to support Memorex 1240, 1242 and 1280 Communications Term inals equipped with USASCII Checking.

• IBM TYPE I - a feature that provides control services for supported IBM asynchronous devices. VRC and LRC checking, autopolling, 2471 break and TYPE I interrupt features are included with this terminal control. Three code groupings are supported: Correspondence, PTTC (Paper Tape Transmission Code)/EBCD, and PTTC/BCD.

• IBM TYPE 111- this featu re provides validation and control functions for remote IBM 2848 and 2845 Display Controllers. Asynchronous speeds of up to 9600 bps a re supported; however, for speeds of 1200 bps or more, data set clocking (in lieu of internal clocking) and synchronous line adapters are required.

• IBM BSC-Synchronous - provides line control services for synchronous terminals (or stations) which conform to the IBM Binary Synchronous Communications (BSC) Conventions. Autopolling and EBCDIC and USASCII codes are included in this support.

Synchronous Transparency is provided to allow for the unrestricted use of all bit patterns within each transmission code type using a special procedure for control character recog n ition.

*This is a tradename of the Teletype Corporation.

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TABLE 1-2.

ASYNCHRONOUS TERMINALS SUPPORTED (USASCII, PTTC/EBCD, PTTC/BCD, Correspondence)

o TERM INAL TYPE SPEED (bps)* TERMINAL TYPE SPEED (bps)*

MRX 1240 110,150,300,600 TTY 37 150

D MRX 1242 1200 IBM 1050 134.5

MRX 1250 110,150,300,600 IBM 1060 134.5

MRX 1252 1200 IBM 1070 134.5 or 600

MRX 1280 110,150,300, IBM 2740 134.5 or 600 600,1200

IBM 2741 134.5 TTY 33 110

IBM 2260/2848 up to 9600 TTY 35 110

IBM 2265/2845 up to 9600

c) TABLE 1-3.

BINARY SYNCHRONOUS TERMINALS SUPPORTED (USASCII, EBCDIC, and TRANSPARENCY)

TERMINAL TYPE SPEED (bps) ** TERM INAL TYPE SPEED (bps)**

MRX 1270 50,000 Maximum IBM 2770 7200 Maximum

MRX/40 and 50 9600 Maximum IBM 2780 4800 Maximum

c IBM 1130 4800 Maximum IBM 3270 ** 4800 Maximum

IBM 1800 4800 Maximum IBM 3704/05** 50,000 Maximum

IBM 2020 50,000 Maximum IBM 3735 ** 2400 Maximum

o IBM 2701 50,000 Maximum IBM 3780 ** 7200 Maximum

IBM 2703 4800 Maximum IBM SYSTE'M/3 50,000 Maximum

*Speeds are termina I lim itations.

o ** IBM speeds are current published maximums.

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