1. CICS-Int1 Introduction to On-Line BATCH – Transactions are accumulated into groups (batches) before processing. ON-LINE – Interactive Transactions entered one at a time via terminals and processed while you wait.

2. CICS-Int2 Introduction to On-Line The main Advantage of On-Line over batch is responsiveness. Batch response time is usually measured in days where On-Line response time is usually measured in seconds! Another advantage is immediate error correction. Disadvantage – COST!

3. CICS-Int3 Introduction to On-Line Four main TYPES of On-Line programs: Menu Inquiry Maintenance Data Entry

4. CICS-Int4 Introduction to On-Line Menu Program: Shows list of functions available and allows user to choose which one to perform. Sometimes other NAVAGATION options are presented also, like HELP or EXIT.

5. CICS-Int5 Introduction to On-Line Inquiry Program Shows a response to a user’s inquiry. For example: A customer number is entered and a list of Video Tapes currently rented is displayed.

6. CICS-Int6 Introduction to On-Line Maintenance Provides for updates by allowing changes, deletions, and additions of data. For example: Changing the address of a customer.

7. CICS-Int7 Introduction to On-Line Data Entry Provides for transaction entry. For example: Entry of an order for a customer. The Customer Number and the required details of an order can be entered and validated.

8. CICS-Int8 Online System Considerations Four Main Areas of Concern: Ease of Use Performance File Integrity Security

9. CICS-Int9 Online System Considerations Ease of Use Common User Access (CUA)  Entry Model (Dumb Terminals) Mainframe CICS, etc.  Graphical Model (Workstations, PC’s) Windows, Linux, etc.

10. CICS-Int10 Online System Considerations Performance Response Time (Measurement)  Time for screen update to occur  Factors affecting response time System load (Number of programs running) Communication traffic load Data traffic (Number of I/O operations required) File activity (Number of files accessed/updated)

11. CICS-Int11 Online System Considerations File Integrity Simultaneous file activity Shared files (Batch program ‘owns’ file) Multiple users with conflicting needs  File (Record/Block) locking

12. CICS-Int12 Online System Considerations Security Logon Procedure (Name/Password) Multi-level Security  RACF Security profile  Alternate Logon’s (Supervisor, etc) Call Back Security, etc.

13. CICS-Int13 Terminal Networks Network connects terminal to host Terminals can be ‘local’ or ‘remote’ Local Short distance (Usually same building) Remote Further distance (Different cities)

14. CICS-Int14 Terminal Networks Local Connection Terminal 3270 Family Controller Multiplexor (Optional) Channel attachment

15. CICS-Int15 Terminal Networks Remote Connection 3270 Family Terminal 3270 Family Controller Modem - SDLC (or BSC) Communication Link Modem - SDLC (or BSC) 3270 Family Controller Channel Attachment

16. CICS-Int16 Terminal Networks IBM’s 3270 family of terminals 3270 Information Display System  3270 Display Stations 3278 – Monochrome 3279 – Seven Color (w/intensity also)  3270 Printers Dot matrix Printers Line Printers Laser Printers

17. CICS-Int17 Terminal Networks IBM 3270 Family (Continued) 3270 Controllers  Connect up to 32 devices to controller  Coaxial cables  Multiplexors (8 units via single cable) Options  Light pens, extended keyboards (languages), extended attributes (highlighting, blinking, etc.)

18. CICS-Int18 Terminal Networks 3270 Emulators PC Programs emulate Mainframe Terminal Adds: upload and download of files Translation from/to EBCDIC/ASCII Also allows screen/file printing Changes PC to ‘FULL SCREEN’ device

19. CICS-Int19 Introduction to CICS Customer Information Control System IBM Product of the 70’s (Intro in 1969) 490 of Fortune 500 use CICS Over 1 billion lines of CICS (COBOL) code Nearly 15 million CICS terminals Nearly 1 million CICS programmers Allows BATCH O/S to handle ONLINE

20. CICS-Int20 Introduction to CICS CICS is interface between O/S & prog CICS acts like an Operating System Manages its own storage Provides its own file and D/B management Has its own TASK manager Runs in its own ADDRESS SPACE

21. CICS-Int21 Introduction to CICS Multitasking is basic feature of CICS CICS allows multiple tasks to operate Uses its own method (not regular O/S) Works same regardless of O/S Multithreading allows program sharing Program must be reentrant No code modification allowed!

22. CICS-Int22 Introduction to CICS Assembler can be used (carefully!) CICS/COBOL produces reentrant code. Users share same program code. Each user gets separate copy of W/S. Users invoke a TRANSACTION

23. CICS-Int23 Introduction to CICS TRANSACTION specifies prog to run TRANS-ID is 4 character unique code Once loaded into CICS storage, it stays. (Unless external request received) Each user is assigned a TASK Task active until RETURN is issued

24. CICS-Int24 Introduction to CICS Tables Each TRANS-ID is defined in PCT TRANS-ID is four chars (w/trailing spaces) PCT = Program Control Table PCT is list of valid TRANS-ID’s Paired with ‘Program Name’ to use Program names are eight characters (wts) IBM TRANS-ID’s start with ‘C’

25. CICS-Int25 Introduction to CICS Tables PPT = Processing Program Table List of all valid program names Used by CICS to determine if in storage. IF not in storage, CICS loads NEW COPY Tables created by programmer with CEDA RDO = Resource Definition OnLine - CEDA

26. CICS-Int26 Intro to CICS Services Three main categories of CICS Services: Data Communications Services Data Management Services CICS Management Services

27. CICS-Int27 Intro to CICS Services Data Communication Services Basic mapping Support (BMS)  Assembler program to handle screen formats. Terminal Control  Interface with VTAM  Send/Receive text to/from terminal

28. CICS-Int28 Intro to CICS Services Data Management No COBOL READ/WRITE Permitted! CICS handles all data requests VSAM, DL/1, and DB/2 Files defined in FCT FCT = File Control Table List of available files, status, type, security

29. CICS-Int29 Intro to CICS Services CICS Management Services Program Control  Allows TASK to call other programs  Some RETURN and some don’t Temporary Storage Control Transient Data, Interval, Storage Control Task, Dump, Trace and Journal Control

30. CICS-Int30 Intro to Program Development Develop complete program specs Design the program Create required CICS table entries Create the BMS Mapset Code the program Compile and Test program Document the program