DAT2330 - Harold Smith Class - Thu Jan 13, 2000

Harold Smith Web Site walk through
- for information on certification - see Harold
- consulting instructions
- manage your own learning; come to me, I don't go looking for you
- use up lab hours before asking me for time outside lab
- I reject email that isn't recognized as a student (spam)
- I use reply button; I don't use special instructions
  - set your own reply address before you email me
- you can book times even on weekends
- don't ask me about network problems, e.g. N drive
  - go to College help page
- learning management guide
  - do read it - help you get the best mark
  - your mark is on my laptop at all times; check with me
  - not all assignments are marked; but all are important
  - marked assignments are spot checks
  - keep up with all the homework, not just the marked assignments
  - follow my directions regarding submission format
  - you are in a picky profession - make sure you can follow instructions
  - help from other students: two heads are better than one
    - limit help to looking for answers
    - help them find answers; do not hand them your homework
    - we want to maintain the high standards; serious about plagiarism
    - look in your instaguide for the directive on plagiarism
    - zero for both people
    - may be more serious penalties - F, expulsion
    - one assignment is a team assignment
    - common solutions are not acceptable
    - we watch the mark spread between labs and exams
      - if you have high lab marks and low exam marks, we will check
    - if you're a top student who doesn't have time to help, send them to me
  - to prepare for exams, do the homework
  - MVS book is a reference book, not a good textbook
  - homework is best learning tool, esp. in MVS section
  - exam questions drawn from homework
- buy the texts ASAP
- homework is posted here
- discussion group available on FreeNet
- post questions so that everyone can see the answer
  - email personal questions
- general student news group; linux news group
- show news group reader, show meaning of "Reply"
- show Unread, threads
- you learn MVS and Linux here; but, there are many out there
- Research Project
  - due Feb 4, 5pm
  - to encourage you to examine other O/S, project is to pick and survey an O/S
  - not AIX or Linux or Win95, Win98 or MVS
  - when you choose an O/S, post a follow-up article about your group
  - post first, research second
  - 3-5 people
  - follow given format *exactly*
  - all projects will be posted
  - must be in HTML (I can help)
  - short, quick coverage; not 25 pages
- please don't chat in class; please step out

Topic 1 - Introduction to Operating Systems
- primary focus is detailed technical knowledge of MVS and Unix
- you must know, in general, what an O/S is
  - your clients may ask you for O/S advice
  - switching O/S requires re-purchasing applications, or rewriting them
- What is an O/S?
  - a program
  - launches other programs (applications)
  - develop applications, debug
  - software intended to aid in the preparation and execution of
    applications progrms
- Win95 has many things that should be applications built-in to O/S
  - too many things built into the O/S
  - MS forgot the purpose of an O/S
  - can't get rid of built-in things
- those who do not learn from the mistakes of the past are doomed to repeat them
  - e.g. antitrust (IBM)
  - early hardware had no O/S - punch cards directly into memory
    - had to have your own I/O package to read disk
    - each hardware change caused programs to be rewritten
  - O/S took over management of hardware
    - changing hardware means changing O/S (drivers)
    - changing O/S means changing applications
    - O/S was intended to insulate application from hardware
    - system programmers handled the O/S; but, now, everyone has to handle
      the O/S - the O/S is no longer invisible
    - everyone has to become a Win95 system programmer!
    - Unix philosophy is better-suited, can hide complexity
- O/S Components
  - Boot Facility (IPL)
    - some method to get loaded into memory from disk/CD/tape/cards
    - "Bootstrap" process, boot deck of cards
    - BIOS chip separate from Processor - it finds first block of next boot
  - Shell (Command Line Processor, GUI, JCL)
    - to tell the O/S what we want it to do 
  (you don't have to know what acronyms stand for, only what they do)
  - Task Management - allocate processor time
  - Memory Management - allocate memory (virtual memory - all modern O/S)
    - very different between O/S!
    - Win95 task manager crashes a lot - BSOD!
      - bells and whistles matter more than stability
    - program size not limited to RAM (virtual memory; swap file)
    - I/O control system (DOS); Data managment (MVS); device drivers
  - security system (not Windows)
  - networking facilities
  - utilities (system tools, text editor, etc.)
    - O/S should not include media players or applications
  - College introduces Windows first, so you may think it's the best
  - don't be blinded by popularity - look at the requirements
  - help facilities (strong in Windows, harder to use in Unix)
    - win help is user level only
    - unix help is deeper
- O/S Terms
  - Kernel (nucleus) - that portion of the OS that is resident
    (running at all times)  - huge for windows due to large O/S
    - can tailor kernel to include only relevant services
  - Batch vs. Interactive processing: periodic vs. real-time
    - win users never experience batch
    - MVS is a superb batch processing O/S - mainframes
    - Win has no batch; Unix has some
    - JCL is hard to learn because it has to support Batch processing
      - many things that you don't have to consider in interactivity
    - e.g. banking statements, tax forms
    - e.g. college services - schedule "right away"
      - transcripts at end of semester
      - paycheque every 2nd week
    - a lot of batch work; batch is really different
  - Spooling - print management - Simultaneous Peripheral Operations On Line
    - applications were able to share the printer
    - your application queues print jobs to disk
    - MVS has complex commands to control spooling
    - MVS can reprint any page from the spool queue, no need to re-run
  - Batch files (DOS); macros; WSH; shell scripts; "procs"
    - Windows Scripting Host (Win2000)
    - you must master this skill so that you can repeat tasks!
  - MultiTasking - more than one program loaded; only one is active
    - supports only one user of the machine
  - MultiProgramming - more than one loaded *and* more than one active
    - support many users of the same machine (keyboards, screens)
- O/S Selection Criteria
  - you cannot answer "which is the "best" O/S"; be more specific
  - Performance - throughput (batch) vs. Response Time (interactive)
  - RASSIM (reliability, availablity, servicablity,
    scalability, integrity, manageability)
    - reliability - how often does it crash?
    - availability - how long is it available?
    - servicability -
    - scalability - can you keep same O/S as needs increase?
    - integrity - security, protection
    - manageability - tools to support many users, many disks, etc.
  - User Friendly - new users vs. experts have different requirements
    - tailorable / customizable
    - fast, efficient, courteous, self-service
  - Costs - pay vendor, upgrading costs, training costs, maintenance costs
    - TCO: total cost of ownership
    - SW, HW, install, support
  - what Applications are available
    - what Software Development Kits?
    - vapourware - promises of nonexistent software
  - "off the shelf" vs. "in house" software (not outhouse software!)
  - hardware support (drivers)
  - technical support
  - Security

- Major O/S analyses