Chapter 1

 Background of the AS/400

1. IBM Midrange Background
	* Began June 1969
	   * System 3/x
	   * Rochester, MN
	   * Punch card design
	   * Target low-end commercial & small-size batch

2. System 3/x Line
	* System 3/x Midrange line
	   * Small, efficient computer
	   * Single computer model - standard

3. System/34
	* System/34
	   * April 1977
	   * First multi-user minicomputer
	   * Low-cost computer

4. System/38
	* System/38
	   * 1975 research project
	   * 1978 announced
	   * Machine independence
	   * New processor
	   * User needed to upgrade
	   * First time contained a relational database
	   * Object-based architecture
	   * Ahead of times

5. System/36 Upgraded Models
	* System/36 upgraded
	   * Many customers preferred to stay with system/36                        
             rather-than System/38

6. AS/400 History
	* Project SilverLake
	   * 1985 started research
	   * New machine
	   * Successor to System/38
	   * New future machine

7. AS/400 History - Continue
	* Application System/400 (AS/400)
	   * June 1988 announced
	   * Improving at about 10% per year
	   * Hardware independent untested until 1995
	   * CISC (Complex Instruction Set Computer)
	      * Instruction length variable

8. AS/400 History - Continue
	* Upgrading
	   * RISC (Reduced Instruction Set Computer)
	      * Equal instruction length
	      * From 48-byte to 64-byte word size
	      * True hardware independence

9. AS/400 History - Continue
	* Enhanced Series or e-series
	   * 1994 development began
	   * Foresaw potential of Internet
	   * Announced August1997
	   * New n-way processors up to 12-way
	   * First package machine
	      * A server configured and preloaded with SAP software

10. Layered Design Concept
	* Layered Architecture
	* Distinguished from traditional computers
	* Key to machine independence

11. Table 1.1 AS/400 Layered Software Architecture

12. Data Storage and Objects
	* Object-based computers
	   * Everything stored on an AS/400 is an stored as an object
	* Objects stored in Libraries
	* Data stored as
	   * EDCDIC - Extended Binary Coded Decimal Interchange Code
	   * ASCII - American Standard Code for Information Interchange

13. Single-level Storage
	* No distinction between disk storage and main memory
	* One large storage area  (single address space)
	   * Memory
	   * DASD
	* Object must be in memory to use or operate on

14. Single-level Storage
	* Automatic divides object into blocks - pages
	* Virtual storage

15. Software
	* Operating System
	* Application Programs
	* Job/Program types
	   * Interactive
	   * Batch