Restricted Distribution
Field Engineering Theory Of Operation
Th is manual is intended for internal use only and may not be
used by other than IBM personnel without IBM's written permissioh.
2260 Display Station, Models 1 and 2 2B4B Display Control, Models I, 2, and 3
(Serial No. SO,OOO Series)
Y27-2046-3
tion of the IBM 2260 Display station Models 1 and 2, and IBM 2848 Display Control Unit, Models I, 2, and 3. However, the description of the 2848 Dis- play Control pertains only to those units whose serial numbers are 60,000 or above.
The following publications can be used to sup- plement the information provided in this manual:
IBM 2260 Display Station, IBM 2848 Display Control Maintenance Manual (Form
Y27 -2047 -2)
IBM 2260 Display Station, IBM 2848 Display Control FE Diagram Manual (Form
Y27 -2048-2)
1052 Printer Keyboard and 1053 Printer Main- tenance Manual (Form 225-3179-2)
Medium Power Standard Power Supplies (Form 223-2799-0)
IBM 1052, 1053 CEMI (Form 225-3179) IBM System/360 I/O Interface - Channel to
Control Unit - Original Equipment Manu- facturers Information (Form A22-6843-3)
ABBREVIA TIONS LIST
The abbreviations used in this manual, together with their definitions, are as follows:
Abbreviation ACK
ASCII CAN CRT DAU DC DS EBCDIC EOM EOT
Definition Acknowledge
American Standard Code for Information Interchange Cancel
Cathode-Ray Tube Data Adapter Unit Display Control Display Station
Expanded Binary Coded Deci- mal Interchange Code
End of Message End of Transmission
changes released in the following F. E. Supple- ments:
Form Number Y27-2165-0
Y27-2171-0
Abbreviation EPO
ETX FC LF LRC MI NAK NDC NL OLSA SMS SOH STX VRC XA
Pages Affected 4-10, 4-11 and 4-18
v through vii, 1-3 through 1-6, 1-21,1-22,2-97, 2-98,2-123, 2-124,2-125, 2-126, 6-1 through 6-4, B-1 through B-3, X-I through X-8 add pages 2-124A and 2-124B
Date
Sept. 11, 1967
Dec. 1, 1967
Definition Emergency Power Off End of Text
Feature Code Line Feed
Longitudinal Redundancy Check Manual Input
Not Acknowledge Nondestructive Cursor New Line
Off Line Selectric Analyzer Standard Modular System Start of Heading
Start of Text
Vertical Redundancy Check Transmit Adapter
This manual has been prepared by the IBM Systems Development Division Product Publications, Dept. S20, CPO Box 120, Kingston, N. Y., 12401.
Address comments concerning the manual to this address.
@
International Business Machines Corporation 1967(4/67)
CHAPTER 1 INTRODUCTION.
Scope of Manual •
IBM 2848 Display Control, General Description IBM 2848 Display Control, Model 1 IBM 2848 Display Control, Model 2 IBM 2848 Display Control, Model 3 IBM 2848 Model Summary • Special 2848 Features
Operator Controls and Indicators CE Panel
IBM 2260 Display Station, General Description Special Features •
Feature 4766 Alphanumeric Keyboard Feature 4767 Numeric Keyboard Control Key Functions
Functional Description •
IBM 2848-2260 Display Complex IBM 2848 Display Control
Channel Adapter • IBM 2848 Common 1053 Printer Adapter Control and Timing IBM 2260 Display Station
System/360 - Channel Adapter Interface General •
Line Description Bus Out • Bus In
Operational Out Request In • Address Out Select Out Hold Out Select In Operational In Address In • Command Out Status In.
Service Out Service In • Suppress Out Clock Out • Metering In • Metering Out Addressing •
Commands and Command Operation.
Write DS Buffer Storage Command Write 1053 Buffer Storage Command Write DS Line Address Command. • Read DS MI (Manual Input) Command Short Read DS MI Command • Read Full DS Buffer Command No Op (No Operation) Command Erase DS Buffer Storage Command Sense Command •
1-1 1-1 1-1 1-2 1-2 1-3 1-3 1-3 1-3 1-3 1-3 1-6 1-6 1-6 1-6 1-6 1-6 1-8 1-8 1-11 1-12 1-13 1-13 1-14 1-14 1-14 1-14 1-17 1-17 1-18 1-18 1-18 1-18 1-19 1-19 1-19 1-19 1-19 1-20 1-20 1-20 1-20 1-21 1-21 1-21 1-21 1-22 1-22 1-23 1-23 1-24 1-25 1-25 1-25 1-25
I
Form Y27-2046-2, -3 FES Y27-2190
Test I/O Command • Interleave Read
Channel-Display Complex - Sequence and Responses Stop Sequence •
Interface Disconnect Sequence Selective Reset Sequence
Read Operation Write Operation System Reset Sequence
Short Control Unit Busy Sequence.
Sense and Status Bytes Sense Byte • Status Byte
Character Codes and Displayable Symbols Displayable Symbols
EBCDIC Code • Keyboard Code
Internal 2848 Six-Bit BCD Code 1053 Printer Code.
Terms and Definitions
CHAPTER 2 FUNCTIONAL UNITS Introduction
IBM 2260 Display Station Cathode-Ray Tube
Eelctron Gun Beam Focusing
Deflection Yoke Assembly Raster
Correction Magnets • Centering Rings Tilting Aquadag Coating Screen Phosphors CRT Electrode Potentials
CONTENTS
1-25 1-25 1-26 1-26 1-26 1-26 1-26 1-26 1-26 1-27 1-27 1-27 1-27 1-28 1-28 1-29 1-30 1-30 1-31 1-31 2-1 2-1 2-1 2-3 2-4 2-4 2-5 2-5 2-5 2-5 2-5 2-6 2-6 2-7 Display Station Electronics for DS Using Older Level Circuit Boards
Video Amplifier Sync Clipper
Horizontal Multivibrator Vertical Phase Detector Vertical Multivibrator Vertical Output Circuit High-Voltage Rectifier Damper Circuit
Display Station Electronics for DS U sing Tube Adapters
Display Station Electronics for DS Using Newer Level Circuit Boards
Display Station Power Supply
B+ Supply for DS U sing Older Level Circuit Boards
B+ Supply for DS Using Newer Level Circuit Boards
-84VDC Supply +48VDC Supply
2-7 2-7 2-8 2-8 2-11 2-11 2-12 2-12 2-12 2-13 2-13 2-13 2-14 2-14 2-14 2-14
2260/2848 - 60,OOOS FETOM (3/68)
Display Station Timing
Organization of Basic Delay Line Slot Vertical Sweep Timing •
Horizontal Sweep Timing Manual Input Keyboard
D escri pti on • Keyboard Mechanics
Bail Contacts • Keystem Contacts
Keyboard Restoring Components Keyboard Interlocks
Keyboard Electronics.
IBM 2848 Display Control Display Adapter
Delay Line Theory Description • Operation
Delay Line Bit Organization.
Buffer Slot Layout Delay Line Controls BCD Data Gating • Video Data Gating Keyboard Operation
Keyboard Priority Keyboard Controls
Keyboard Data Bit Conversion and Gating Timing and Clock Circuits •
Oscillator
A and B Delay Pulse Circuit Bit Ring Counter •
Even-Odd Display and Late Triggers Buffer Parity Control Circuit Row Counter
Segment Counter
Character Display Colunm Ring Counter Line Counter
Sync Generator
Vertical Sync Generation Horizontal Sync Generation Horizontal Blanking Sync Pulse Delay Circuit Reset Controls • TIC Sample Decoder
General • Circuit Operation BCD Gating Outputs
Character Generator Read Gate Generation.
Display Addressing General •
Address Encoder and Address Register Display Group Decoder •
Display Address Decoder TIC Found Latch • Write A and Write B Latches
Keyboard Write Operation Erase Operation
Interface Write Operation TIC Write and Erase Operation
ii (3/68)
"
2-14E 2-14 2-17 2-17 2-17 2-18 2-18 2-18 2-24 2-24 2-25 2-25 2-27 2-29 2-29 2-29 2-29 2-30 2-31 2-35 2-35 2-35 2-36 2-36 2-36 2-40 2-40 2-43 2-45 2-45 2-47 2-47 2-50 2-50 2-52 2-52 2-54 2-54 2-56 2-56 2-56 2-57 2-57 2-57 2-60 2-62 2-62 2-62 2-62 2-63 2-63 2-65 2-65 2-65 2-66 2-66 2-69 2-69
Write EOM (NDC Only) • Other Write Latch Control Signals.
Serializer.
Write Data Operation Write TIC Operation Other Write Operations Deserializer •
Common Buffer Register Common Buffer Register Inputs
Sense Amplifier Inputs End of Message Inputs.
Keyboard Inputs Interface Inputs Delay Line Inputs Reset Inputs
Common Buffer Register Outputs Register Control
Set EOM
SOM, New Line, and EOM Decode Character Generator
Core Plane • Cell Selection
Read Winding Connection and Operation Sense Winding Connection and Operation Binary Data Outputs
Decoders.
W rite Control Read Control
Position Storage and Compare Logic General •
Counter Storage Control • Row Counter Storage and Compare Segment Storage and Compare Column Storage and Compare • Line Counter Storage and Compare Display Compare •
Left/Right Storage Buffer Selection Circuits Video Buffer Selection
Nondestructive Cursor Generation.
W rite Line Address Command Decode Decoder Operation Keyboard Command Decode Parity Control •
Parity Assignment • Parity Update • Parity Check Parity Write Control Parity Read Gate Control Printer Adapter Controls • Control Latches and Triggers Channel Adapter •
Block Diagram Analysis Out Tag Delays
Command Out Delayed Service Out Delayed Control Latches
2-69 2-69 2-69 2-70 2-73 2-73 2-73 2-74 2-74 2-76 2-76 2-76 2-76 2-76 2-76 2-76 2-76 2-79 2-79 2-80 2-81 2-81 2-82 2-82 2-84 2-84 2-84 2-84 2-86 2-86 2-86 2-92 2-92 2-92 2-94 2-97 2-97 2-97 2-98 2-101 2-102 2-102 2-102 2-103 2-106 2-106 2-108 2-108 2-108 2-111 2-111 2-112 2-112 2-112 2-115 2-115 2-116 2-116
Cha1ll1el Request • • Control Unit Request • Status Request Service Request Operational In Latch Busy Latches. •
Interface Busy Device Busy.
Address In Status In Service In • Stack Status Latch Stop Latch • •
Remember End and Local- Remote Latches Command Chaining and Inhibit Attention Latches.
Command Chaining • Inhibit Attention • Disc01ll1ect and Reset Circuits Hold Select Circuits •
Control Unit and Device Addressing Channel-Originated Address Control Unit-Originated Address Printer Address.
Manual Address Command Decode Sense and Status Registers
I/O Request and Character Register Control I/O Request
Character Register Control • Character Register and Code Converter •
Character Formats Start Symbol New Line Symbol Check Character • Circuit Description
Cha1ll1el Adapter Operational Sequences Cha1ll1el-Initiated Sequences •
Sense.
Erase.
No Operation Test I/O. •
Command-to-Busy Device • Control U nit Busy
Control-Unit-Initiated ~equences. • Data Transfer •
Sense Transfer • Status Transfer Special Sequences
Stack Status Stop • • Printer Adapter
Printer Adapter Circuit Description Ring Counter •
Print In Buffers Print In Buffer 1 Print In Buffer 2 Case Change Check Parity Assignment • Delay Line. •
2-117 2-117 2-117 2-117 2-117 2-118 2-118 2-118 2-118 2-118 2-119 2-119 2-119 2-119 2-121 2-121 2-122 2-122 2-122 2-125 2-125 2-126 2-126 2-126 2-126 2-129 2-131 2-131 2-131 2-132 2-132 2-133 2-133 2-133 2-133 2-133 2-133 2-137 2-138 2-138 2-138 2-139 2-140 2-141 2-141 2-143 2-145 2-146 2-146 2-146 2-147 2-148 2-148 2-149 2-149 2-149 2-150 2-150 2-150
Form Y27-2046-2, -3 FES Y27-2190 Parity Check Circuit •
Print Out Buffer.
FWlction Decoder Keyboard Print Operation
Printer Adapter Input Operation
Printer Operation, Case Change Not Required.
Printer Operation, Case Change Required EOM and Display Adapter Parity Check • Print Cycle Operations •
Print Cycle and No Parity Check Print Cycle with Parity Check
Print Cycle with EOM and Chk Chac Latch On.
Print Cycle with EOM Set and Chk Chac Latch Off
Write 1053 Buffer Storage
CHAPTER 3 PRINCIPLES OF OPERATION General
Channel Adapter Operational Sequences Cha1ll1el-Initiated Sequences
Read or Write Selection Sense
Erase No Operation Test I/O
Command to Busy Device Control Unit Busy •
Control-Unit-Initiated Sequences.
Data Transfer • Sense Transfer. • Status Transfer • Special Sequences
Stack Status Stop • • • Keyboard Operations
Alphanumeric Key New Line Key • Up and Down Keys
Advance Key (NDC Feature)
Advance Key (Destructive Cursor Feature) Start Key
Enter Key Backspace Key Erase Key Print Key
CHAPTER 4 FEATURES Introduction •
Remote Interface Adapter General. •
ASCII Code Set
IBM 2701 Data Adapter Unit Data Sets
ASCII Communications Control Characters 2848 Display Control Modes of Operation
Control Mode • Text Mode • • • • 2848 Display Control Status
2-150 2-151 2-151 2-151 2-151 2-152 2-152 2-152 2-159 2-159 2-159 2-159 2-159 2-159 3-1 3-1 3-1 3-1 3-1 3-1 3-2 3-2 3-2 3-2 3-3 3-3 3-3 3-4 3-4 3-5 3-5 3-5 3-6 3-6 3-7 3-7 3-8 3-8 3-8 3-10 3-10 3-11 3-11
4-1 4-1 4-1 4-2 4-2 4-2 4-2 4-4 4-4 4-4 4-4 4-5
2260/2848 - 60,000S FETOM (3/68) iii
Transmit Status Selected Status Nonselected Status Receive Status Addressing Sequence
Commands and Command Operation Specific Poll to a 2260 Display Station Specific Poll to the 1053 Printer General Poll
Read Addressed Full DS Buffer.
Write Addressed DS Erase/Write Addressed DS Write Printer
Printer Request Condition Write DS Line Address
Summary of Sequences and Responses 2848 Display Control Sequences and Responses Channel Sequences and Responses
Functional Units Adapter Data Flow
Write Operation Read Operation Ring Counter
1.2-kc Clock and Serdes Control S erializer- D eserializer Register.
Serdes Data Inputs Serdes Data Outputs Special Serdes Outputs Register Operation Character Register
Control Mode Operation.
Write Operation Read Operation Address Register
Write/Channel Initiated Read Operation Read Manual Input Operation
Command Decoder ASCII Command Decoder ASCII Command Coder • LRC Register
LRC Operation During Write LRC Operation During Read Parity Check and Assignment •
Parity Assignment Parity Check
Serializer and 7-to-6-Bit Code Converter Character Register Inputs
Common Buffer Register Inputs Special Character Inputs Read and Write Mark Inputs Delay Line.
Deserializer and Output Register Deserializer
Address Transfers to Output Register Output Register Empty Latch Write and Write Command Controls Read and Read Command Controls 1053 Printer Controls
iv (3/68)
4-5 4-5 4-5 4-5 4-5 4-6 4-6 4-8 4-10 4-10 4-12 4-13 4-13 4-14 4-15 4-16 4-17 4-18 4-19 4-19 4-19 4-21 4-21 4-21 4-21 4-22 4-22 4-22 4-22 4-22 4-23 4-23 4-23 4-23 4-23 4-23 4-24 4-24 4-24 4-25 4-25 4-25 4-26 4-26 4-26 4-26 4-26 4-27 4-27 4-28 4-28 4-28 4-28 4-29 4-29 4-29 4-29 4-29
Theory of Operation • General •
Addressing Sequence - Write Operation Channel Response - SOH, EOT Character Channel Response - DC AAddress
Channel Response - 2260 DS Address Command - Write Addressed DS • Remote Interface Response - ACK Character Channel Response - STX Character • Channel Response - Text Character • Delay Line Readout - Write Operation
Deserializer and OutPllt Register Transfer - Write Operation
Channel Response - ETX Character Channel Response - LRC Character Channel Response - EOT Character Command - Write Printer
Address Sequence Initial Adapter Response
Printer Ready and Not Busy • Printer Busy
Data Transfer
Address Sequence - Read Operation Command - Specific Poll to 2260 DS 2848 DC Response - STX Character • 2848 DC Response - 2260 DS Address 2848 DC Response - Text Character.
Delay Line Readout - Read Operation
Deserializer and Output Register Transfer - Read Operation
Output Register to Character Register Transfer 2848 DC Response - ETX Character • Buffer Parity Check - Read Operation 2848 DC Response - LRC Character •
Channel Response - 5TX to Read End Sequence Write DS Line Address
Write/Erase Command
Write Erase Command - Channel Response (STX).
General Poll
CHAPTER 5 POWER SUPPLIES AND CONTROL I ntroducti on
60-Cyc1e Power System Initial Power Distribution Power Control Sequences
Power On - Remote Power On - Local • Power Off - Remote Power Off - Local • Emergency Power Off Fault Condition Operation
Circuit Breaker Open During Local Operation Circuit Breaker Open During Remote Operation
Overtemperature Conditions DC Power Supply •
SO-Cycle Power System Initial Power Distribution Power Control Sequences
4-29 4-29 4-30 4-30 4-30 4-30 4-34 4-34 4-35 4-38 4-41 4-41 4-41 4-43 4-43 4-45 4-45 4-45 4-45 4-46 4-46 4-46 4-46 4-46 4-48 4-51 4-51 4-51 4-51 4-53 4-53 4-53 4-57 4-57 4-57 4-59 4-59 5-1 5-1 5-1 5-1 5-1 5-1 5-1 5-1 5-4 5-4 5-4 5-4 5-4 5-4 5-4 5-4 5-4 5-8
Power On - Remote Power On - Local • Power Off - Remote • Power Off - Local • Emergency Power Off Fault Condition Operation
Circuit Breaker Open During Local Operation Circuit Breaker Open Dur,ing Remote Operation
Contactor PK1 Overload Contacts Open in Local
Contactor PK1 Overload Contacts Open in Remote.
Reset of PK1 Overload Contacts Overtemperature Conditions Thermal Circuit Reset • DC Power Supplies
CHAPTER 6 CONSOLE AND MAINTENANCE FEATURES
Introduction
Controls and Indicator Functions
2848 Display Control, Operator's Panel 2848 Display Control, CE Panel • 2260 Display Station
Operating Control Alphanumeric Keyboard
Frontispiece IBM 2260 Display Station - 2848 Display Control •
1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 1-12 1-13
SummarY of IBM 2848 Display Control Models • •
IBM 2848 Display Control Features (2 Sheets)
Optional Alphanumeric Keyboard for
2260 DS • • • • •
Optional Numeric Keyboard for 2260 DS
IBM 2848 - IBM 2260 Display Complex, Block Diagram •
IBM 2848 - IBM 2260 Block Diagram. • Timing and Clock Circuits, Simplified Block Diagram •
CRT Display Organization • 2260 Display Station, Block Diagram.
Typical Address Assignments, Model 1 2848 DC.
Commands and Their Code Structure. • Displayable Symbols • • • • • • EBCDIC Code Used for 2848-System/360 Channel Transfers •
5-8 5-8 5-8 5-8 5-8 5-8 5-8 5-8 5-8 5-9 5-9 5-9 5-9 5-9
6-1 6-1 6-1 6-1 6-1 6-1 6-1 6-2
viii 1-3 1-4 1-7 1-7 1-8 1-9 1-11 1-15 1-17 1-21 1-22 1-28 1-29 1-14
1-15 1-16
Keyboard Code. 1-30
1-17 2-1
Internal 2848 Six-Bit BCD Code 1-31 1053 Printer Tilt-Rotate Codes and Their 2848 Six-Bit BCD Code Equivalents. 1-32 Terms and Definitions (2 Sheets) 1-33 Display Station Block Diagram 2-2
Form Y27-2046-2, -3 FES Y27-2190 Numeric Keyboard
Control Key Functions
APPENDIX A MACHINE CHARACTERISTICS. • APPENDIX B SPECIAL CIRCUITS
Introduction
Integrator Card A, Type FYM Integrator Card B, Type FYN
Four Diode-Coupled 3-Way AND Circuit, Type FZK.
Video Mixer, Type EFY. •
Sense Gate and Output Sense Level, Type FYZ Reed Relay, Type FYF •
Reed Relay, Type YPM •
APPENDIX C LANGUAGE FEATURES Feature Description • •
Identification and Instruction Label Changes Character Codes • •
Character Generator Modification 1053 Printer Print Element Keyboard Changes
French Keyboard • • German Keyboard United Kingdom Keyboard INDEX
6-2 6-2 A-1 B-1 B-1 B-1 B-1 B-1 B-1 B-2 B-3 B-3 C-1 C-1 C-1 C-1 C-1 C-1 C-1 C-1 C-1 C-2 X-1
ll..LUSTRATIONS
2-2 Composite Video Signal (One Vertical
Scan) 2-3
2-3 Cathode-Ray Tube 2-3
2-4 CRT Electron Gun 2-4
2-5 Deflection Coil Currents and Raster
Relationship 2-6
2-6 Persistence Characteristics of P4 and P39
Phosphors 2-7
2-7 Display Station, Electrical Schematic Diagram for DS Using Older Level
Circuit Boards 2-9
2-7A Display Station Electrical Schematic
Diagram for DS Using Tube Adapters 2-14A 2-7B Display Station Electrical Schematic
Diagram for DS Using Newer Level
Circuit Boards 2-14C
2-8 Display Station, Power Supply For 50-
Cycle Operation 2-14E
2-9 Display Station Timing •
. .
2-152-10 AlphanumeriC Keyboard, Bottom and
Rear Views •
.
2-192-11 Key Position 2-20
2-12 Permutation Bar and Keyboard Latch
(Normal) 2-20
2-13 Permutation Bar and Keyboard Latch
(Tripped) 2-20
2-14 Keystem Numbering Chart • 2-21
2-15 Keystem Number and Bail Selection For
Alphanumeric Keyboard 2-22
2260/2848 - 60,000S FETOM (3/68) v
2-16 2-17 2-18 2-19 2-20 2-21 2-22 2-23 2-24 2-25 2-26 2-27 2-28 2-29 2-30 2-31 2-32 2-33 2-34 2-35 2-36 2-37 2-38 2-39 2-40 2-41 2-42 2-43 2-44 2-45 2-46 2-47 2-48 2-49 2-50 2-51 2-52 2-53 2-54 2-55 2-56 2-57 2-58
vi (3/68)
Keystem Number and Bail Selection for Numeric Keyboard
Key Position (Latched and Tripped) • Interlock Disks
Interlock Disks (Partial) • Keyboard Electronics
Keyboard Data Transfer Timing Display Control, Simplified Block Diagram
Delay Line Module
Delay Line Module, Simplified Block Diagram
Delay Line Timing Buffer Slot Layout
Delay Line Controls and BCD-Video Gating
Delay Line Control Timing Delay Line Timing, One Slot Keyboard Assignments for Model 3 Machines
Keyboard Priority
Keyboard Controls and Keyboard Data Bit Conversion and Gating •
Timing and Clock Circuits, Simplified Block Diagram •
Oscillator and A-B Delay Pulse Circuit Bit Ring Counter •
Even-Odd Display Trigger Circuit Buffer Parity Control Circuit Row Counter
Segment Counter
Character Display Column Ring Counter.
Line Counter Sync Generator Sync Generator Timing Sync Pulse Widths.
Reset Controls •
TIC Sample Time Decoding
TIC Sample Decoding, Buffer 1 and 2 • Function of TIC Sample Decoder Circuit Groups
Use of .Character Column Outputs as Character Generator Read Gates • Display Addressing
Address Encoder Outputs. • Write A and Write B Latches, Timing Chart
Write A and Write B Latches
Even and Odd Display Signals, Timing Chart
Serializer, A Delay Serializer, B Delay
Serializer Data and Inputs and Even-Odd Bit Sequences. • • •
Deserialization of Delay Line Data at CBR Inputs. • • • •
2-23 2-24 2-25 2-25 2-26 2-27 2-28 2-30 2-31 2-32 2-33 2-37 2-39 2-41 2-43 2-43 2-44 2-45 2-46 2-48 2-49 2-49 2-50 2-51 2-52 2-53 2-55 2-56 2-56 2-58 2-59 2-61 2-62 2-63 2-64 2-65 2-66 2-67 2-70 2-71 2-72 2-73 2-74
2-59 2-60 2-61 2-62 2-63 2-64 2-65 2-66 2-67 2-68 2-69 2-70 2-71 2-72 2-73 2-74 2-75 2-76 2-77 2-78 2-79 2-80 2-81 2-82 2-83 2-84 2-85 2-86 2-87 2-88 2-89 2-90 2-91 2-92 2-93 2-94 2-95 2-96 2-96A 2-97 2-98 2-99 2-100 2-101 2-102 2-103
Common Buffer Register
Common Buffer Register Input Signals Common Buffer Register Controls • SOM, New Line, and EOM Decode Circuit
Common Buffer Register Control Codes Character Generator, Block Diagram.
Character Generator Timing Core Plane Layout and Cell Selection Selection, Read, and Sense Winding Connections
Generation of Binary Data from Memory Cell • • • •
Low Order Decoder and Driver • Character Generator Write Control Character Generator Read Control Circuits •
Function of Position Storage Circuits • Counter Storage Control. • Counter Storage Control Outputs • Row Counter Storage
Vertical Segment and Column Storage on Compare
Generation and Purpose of Save Line Counter Signals
Buffer Selection and Display Compare Video Buffer Selection, A delay • Video Buffer Selections for A Delays.
Nondestructive Cursor Generation.
Display of NDC Cursor - Even and Odd Write DS Line Address Decode and Gating
Write Line Address Decoder Operation • Keyboard Command Decoder and Command Latches
Parity Circuits. • Printer Adapter Controls •
Control Latches and Trigger Functions (3 Sheets)
Channel Interface Controls • Out Tag Delays
Address In Latch • • Status In Latch •
Remote End, Local-Remote
Command Chaining, Inhibit Attention Disconnect and Reset
Hold-Select Circuit for Units not Equipped with Isolation Feature
Hold-Select Circuit for Units Eqnipped with Isolation Feature.
Control Unit and Device Addressing • • Command Byte Format
Command Decode I/O Request.
Character Register Control • Character Register Bits 0-3. • Character Register Bits 4-7 •
2-75 2-76 2-77 2-79 2-80 2-80 2-81 2-82 2-83 2-83 2-84 2-85 2-87 2-89 2-90 2-91 2-93 2-95 2-97 2-99 2-101 2-102 2-103 2-104 2-105 2-106 2-107 2-109 2-111 2-113 2-116 2-117 2-119 2-120 2-121 2-122 2-123 2-124 2-124A 2-127 2-129 2-130 2-131 2-132 2-134 2-135
2-104 2-105 2-106 2-107 2-108 2-109 2-110 2-111 2-112 2-113 2-114 2-115 2-116 2-117 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 4-14 4-15 4-16 4-17 4-18 4-19 4-20 4-21 4-22 4-23 4-24
Channel-Initiated Selection (Read or Write)
Sense Operation Erase Operation No Op Operation Test I/O Operation Test I/O To Busy Device Control U nit Busy Sequence.
Control Unit Initiated Data Transfer (Read or Write)
Sense Transfer • Status Transfer Stack Status Sequence Stop Sequence •
Printer Adapter, Simplified Block Diagram
Printer Adapter, Logic Diagram (3 Sheets)
Remote Display Complex Configuration.
ASCII-8 Code Set.
Ten-Bit Format of Transmitted ASCII Characters •
Typical Remote Device Address Assign- ments
2848-2260 Commands (Remote) • Sequence/Response Diagram - Specific Poll to 2260 DS
Sequence/Response Diagram - Specific Poll to Printer •
Sequence/Response Diagram - General Poll
Sequence/Response Diagram - Read Addressed Full DS Buffer
Sequence/Response Diagram - Write Addressed DS • • •
Sequence/Response Diagram - Erase/
Write
Sequence/Response Diagram - Write Printer • • • • Sequence/Response Diagram - Line Address Write
Display Line Addresses (Remote) • Remote Interface Adapter, Data Flow Diagram
Command Decoder Function Codes • Character Register Control. • • Channel Response - SOH-EOT and DC Address Characters
Channel Response - Device Address Character
Channel Response - Command Character 2-136 2-137 2-138 2-139 2-140 2-141 2-142 2-143 2-144 2-145 2-147 2-148 2-149 2-153 4-1 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-11 4-12 4-14 4-15 4-16 4-17 4-20 4-24 4-31 4-32 4-33
Decode • 4-35
Remote Interface Response - ACK
Character 4-36
Channel Response - STX Character 4-37 Channel Response - Text Character 4-39 Delay Line Readout Control (2 Sheets) 4-40
4-25
&-26 4-27 4-28 4-29 4-30 4-31 4-32 4-33 4-34 4-35 4-36 5-1 5-2 6-1 6-2 6-3 6-4 6-5 6-6 6-7 B-1 B-2 B-3 B-4 B-5 B-6 C-1 C-2 C-3 C-4 C-5 C-6 C-7 C-8 C-9 C-lO C-ll C-12
Channel Response - ETX and LRC Character
Write Printer Control. • Specific Poll Command Decode • I/O Request Control •
2848 DC Response - STX Character 2848 DS Response - Device Address Read Operation - Common Buffer to Serializer Transfer
2848 DC Response - ETX Character • Read Operation - Buffe!: Parity Check Control
2848 DC Response - LRC Character Write/Erase Command •
General Poll Operation (2 Sheets) • 60-Cycle Power Distribution and Control (2 Sheets)
50-Cycle Power Distribution and Control (3 Sheets)
Operator's Panel - IBM 2848 CE Panel - IBM 2848
2848 Display Control Operator's Panel Controls and Indicators •
2848 Display Control CE Panel Controls and Indicators. •
2260 Display Station Alphanumeric
4-42 4-44 4-47 4-48 4-49 4-50 4-52 4-54 4-55 4-56 4-58 4-60 5-2 5-5 6-1 6-2 6-3 6-4
Keyboard 6-5
2260 Display Station Numeric Keyboard. 6-5 Function of 2260 DS Control Keys (2
Sheets) • • 6-6
Integrator Card A, Type FYM • B-1 Four Diode Coupled 3-Way AND Circuit,
Type FZK B-2
Video Mixer, Type EFY • B-2
Output Sense Level and Sense Gate,
Type FYZ B-3
Reed Relay, Type FYF • B-3
Reed Relay, Type YFM. B-3
Identification and Instruction Label
Summary C-2
Language Feature Character Codes C-3 1053 Printer Typehead, Language Symbol and Character Variations
Graphic Character and Function Key Change Summary. •
French Alphanumeric Keyboard French Numeric Keyboard • Keystem Number and Bail Selection, French Alphanumeric Keyboard German Alphanumeric Keyboard • • German Numeric Keyboard
Keystem Number and Bail Selection, German Alphanumeric Keyboard • United Kingdom Alphanumeric Keyboard
United Kingdom Numeric Keyboard •
C-3 C-3 C-4 C-4 C-5 C-5 C-6 C-6 C-7 C-7
2260/2848 - 60,000S FETOM (11/67) vii
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viii (4/67)
SCOPE OF MANUAL
This manual describes the capabilities and the theory of operation of the IBM 2260 Display Station and the IBM 2848 Display Control (see Frontispiece).
The manual is divided into six chapters and three appendices:
1. Chapter 1, Introduction, provides a func- tional description of the equipment, including the major data flow and control signal paths.
It also includes a description of the interface of the 2848 with System/360, a description of the feature structures of the 2848 and 2260, and reference data (code sets, command structure, etc.) required for an overall con- cept of equipment operation.
2. Chapter 2, Functional Units, gives a detailed description of the operation of the logic areas of both the 2260 and 2848, with simplified logic diagrams and timing charts.
3. Chapter 3, PrinCiple s of Operation, pre sents the theory of operation for the IBM 2848 Dis- play Control through the use of a compre- hensive set of flow charts.
4. Chapter 4, Features, presents the theory of operation of the remote interface adapter used in remote applications.
5. Chapter 5, Power Supplies and Control, ex- plains the operation of the IBM 2848 Display Control power supply, control, and distri- bution network. (Because of its integral relation with other display station circuitry, the IBM 2260 power network is discussed in Chapter 2.)
6. Chapter 6, Console and Maintenance Features, describes the function of the controls and in- dicators located on the operator and CE panels of the IBM 2848 Display Control.
7. Appendix A, Machine Characteristics, sum- marizes equipment capabilities and charac- teristics.
8. Appendix B, Special Circuits, describes the special circuits found in the 2848 Display Control.
9. Appendix C, Language Features, describes the language features available with the 2260 Display station.
There are three models of the IBM 2848 Display Control: Models 1, 2, and 3. This manual describes the operation of Model 3, which is the largest (in terms of the number of characters displayed) and the most complex. Once Model 3 operation is un-
CHAPTER 1. INTRODUCTION
derstood, the operation of Models 1 and 2 will be apparent. When the manual is used as reference material by those interested in Model 1 or 2 only, information unique to the Model 3 can be disre- garded.
Similarly, the IBM 2260 Display Station can be used as an output-only device when it does not include either of the two input keyboards (numeric and alphanumeric) that are available as special features. Throughout this manual it is assumed that the 2260 includes an input keyboard, so that the 2260' s full I/O capabilities can be described. When the manual is used as reference for output-only display stations (no keyboard), all data pertaining to keyboard input operations can be disregarded.
The output capability (video display) is functionally separate from keyboard input operation.
Other features such as the printer adapter, channel adapter, and destructive and nondestructive cursor have been incorporated within the frame- work of the Functional Units chapter to permit a thorough analysis of the more comprehensive Model 3 tied to an IBM System/360 via the channel adapter.
Although some of the features could have been placed in Chapter 4, certain advantages do accrue with the method selected. The interrelationships between the features and the adapters become more apparent when viewed and discussed on an overall systems basis rather than separated individually.
As other features or optional equipment become available, they will appear in Chapter 4, Features.
IBM 2848 DISPLAY CONTROL, GENERAL DESCRIPTION
The IBM 2848 Display Control contains the storage and control logic required to interface the 2848 with either a System/360 selector or multiplexor channel or a communications data set. (The latter configuration permits remote operation of the dis- play group.) The IBM 2848 Display Control can also control up to 24 IBM 2260 Display Stations.
The 2848 Display Control is available in three basic models; each can be supplemented by certain features to expand its basic display capabilities and to provide the display control with special functional abilities. The 2848 Display Control is described in the following paragraphs by first considering the capabilities of the three basic models and the feature combinations that can be selected to supplement each model. Then each feature is described in respect
2260/2848 - 6O,000S FETOM (4/67) 1-1
All three 2848 models offer a choice of operating voltages (primary input of 208vac or 230vac) and exterior cabinet colors (red, yellow, blue, or gray, to permit aesthetic compatibility with the host System/360). These options are not discussed in respect to each model, however.
IBM 2848 Display Control, Modell
The basic IBM 2848 Model 1 is capable of operating two 3355 Display Adapters; each 3355 can service two IBM Model 2 2260 Display Stations. The Modell can generate a display that consists of six rows, each containing 40 characters (240 characters total), on the CRT of all 2260 Display Stations associated with the display control. The basic Model 1 also includes a choice of the 9011 Channel Adapter, the 9012 Data Set Adapter (1200 bps), or the 9013 Data Set Adapt- er (2400 bps) for interfacing with the host System/
360.
Through incorporation of additional optional features, 2848 Model 1 capabilities can be extended to include the following:
1. The ability to drive six additional 3355 Dis- play Adapters (via 3857 Expansion Panel), four additional 3355's (via 3858 Expansion Panel, or ten additional 3355's (via 3857 and 3858). A maximum of 24 IBM 2260 Dis- play Stations (Model 2), each displaying a 240-character (maximum) message, can thus be accommodated.
2. The ability to drive the 7927 Printer Adapter, which controls an IBM 1053 Model 4 Printer, to provide a permanent record of display group data under either program or operator control.
3. A nondestructive cursor (character-entry and display-position indicator and locator) that can be moved within the display area without disturbing or destroying the data displayed on the CRT of the 2260 Display Station.
4. A line-addressing feature which enables the processor, during write operations, to select anyone of the six lines within the 2260 Dis,""
play Station CRT display under program con- trol. '
5. A Foreign Language feature that equips the 2848 Display Control with the character set and operator control designations in the languages of France, Germany, and United Kingdom.
1-2 (4/67)
Display Adapter which services two IBM Model 2 2260 Display stations. The Model 2 can generate a display consisting of 12 rows, each containing 40 characters (480 characters total), on the CRT of all 2260 Display Stations associated with the dis- play control.
The basic Model 2 also includes a choice of the 9011 Channel Adapter, the 9012 Data Set Adapter (1200 bps), or the 9013 Data Set Adapter (2400 bps) for interfacing with the host System/360.
other optional features can be selected to extend the capabilities of the basic Model 2. These ex- tended capabilities include:
1. The ability to drive three additional 3356 Display Adapters (via 3858 Expansion Panel), four additional 3356 Display Adapters (via 3857 Expansion Panel), or a maximum of seven additional 3356 Display Adapters (via 3357 and 3858 Expansion Panels). Since each additional 3356 Display Adapter enables the 2848 Display Control Model 2 to service two Model 2 2260 Display Stations, the display station complement associated with the Model 2 can vary from 1 to a maximum of 16, with each associated display station capable of dis- playing a 480-character message.
2. The 1053 Printer control, nondestructive cursor, line-addressing capabilities, and language features already described in con- junction with the 2848 Display Control Model 1.
IBM 2848 Display Control, Model 3
The basic IBM 2848 Model 3 can operate one 3357 Display Adapter which services two IBM Model 1 2260 Display Stations. The Model 3 can generate a display conSisting of 12 rows, each containing 80 characters (960 characters total), on the CRT of all 2260 Display stations associated with the dis- play control.
The basic Model 3 also includes a choice of the 9011 Channel Adapter, the 9012 Data Set Adapter (1200 bps), or the 9013 Data Set Adapter (2400 bps) for interfacing with the host System/360.
other optional features can be selected to extend the capabilities of the basic Model 3. These ex- tended capabilities include:
1. The ability to drive up to three additional 3357 Display Adapters and, consequently, a maximum of eight Model 1 2260 Display stations, with each display station displaying a 960-character (maximum) message.
ruM 2848 Model Summary
Figure 1-1 summarizes the three 2848 models with· respect to the standard customer options, the applicable feature adapters, the models and num- ber of 2260 Display stations that can be serviced, and the maximum displayable message length.
Special 2848 Features
Each of the customer-selection and special features that can be chosen to complement the three basic 2848 models is described in Figure 1-2. The in- formation provided on each feature consists of the feature code, the feature function, the 2848 models to which the feature can be attached, and any pre- requisite features. Language features are described separately in Appendix C.
The Isolation-Feature defined at the end of Figure 1-2 provides improved equipment performance by eliminating undesired logic signals that occur while power is removed from the unit. This feature enables the CE to perform maintenance tests on an "isolated"
unit without affecting overall system operations. The feature is implemented by providing DSBL REQUEST/
INTF DSBLD switch (and indicator) on the 2848 op- erator's panel and a special selection Circuit modi- fication (explained in Chapter 2 under "Hold Select Circuits").
Operator Controls and Indicators
The 2848 controls and indicators available to the operator are limited to the control of unit power.
Maximum Associated
The controls (or indicator) and their functions are as follows:
1. Power On switch: provides ac power to dc power supplies.
2. Power Off switch: removes ac power from dc supplies.
3. Power On-Off indicator: lights when unit ac and dc power is on.
4. DSBL REQUEST/INTF DSBLD pushbutton/
indicator: permits a unit equipped with the Isolation Feature to be logically disconnected from the system.
5. REMOTE-LOCAL: in LOCAL, permits op- erator to control unit power; in REMOTE, transfers power control to system.
CE Panel
The 2848 Display Control is provided with aCE (maintenance) panel to permit local operation of the unit during checks and/or maintenance.
ruM 2260 DISPLAY STATION, GENERAL DESCRIPTION
The basic ruM 2260 Display Station contains the CRT display used to present data transferred from the associated System/360 and processed in the 2848 Display Control. There are two models of the ruM 2260 Display station: Modell, which is used with the Model 3 2848 Display Control only, and
2260 Display
Model Optional Feature Stations Maximum Display
Number Customer Opt ions Adapters Available Possible Length
1 9011 Channel Adapter, or 3355 Display Adopter. 24 Six rows of 40 char- 9012 Data Set Adapter 7929 Pri nter Adapter. (Model 2) acters each (240 (1200 bps), or 3857 Expansion Panel. characters total).
9013 Data Set Adapter 3858 Expansion Panel.
(2400 bps). 4787 Line Addressing.
5340 Nondestructive Exterior colors of red, Cursor.
yellow, bl ue, or gray. 5341 Nondestructive Cursor Adopter.
Operates on primary power of 208voc or 230vac.
Language Features
2 Some as Modell. Same as for Model 1 16 Twelve rows of 40 except that 3356 Dis- (Model 2) characters each (480 play Adapter replaces characters total).
3355 used with Modell.
3 Same as Modell'. 3357 Di spl ay Adapter. 8 Twel ve rows of 80 3857 Expansion Panel. (Modell) characters (960 4787 Line Addressing. characters total).
5340 Nondestructive Cursor.
5341 Nondestructive Cursor Adapter.
7928 Printer Adapter.
Figure 1-1. Summary of IBM 2848 Display Control Models
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