CS225,  Fall 2006, Wednesday, Dec.6, Day 42  rev. 8pm 12/7

TicTacToe Presentation to the world, Friday, Dec. 8, (in Study Week.) Time 1 to 2   We will NOT be reworking any more code in class.
Post on the Wiki ASAP,  what you have working (however simple); or if not, something whose bugs you can't solve.
Have ready to hand in, Last class or at Presentation, printed out:
your code
, cover pages (Sub documentation. Algorithm if not obvious), Self-evaluation (modified 11/27)

Take home exam available no  later than Friday morning at 11:00, due by noon Thursday Dec. 14
  --to me or to a Shilepsky personally
, or all the way under my door.
It will have quite a lot of choice in the problems you need to do; summing  to a desired amount.  It may be available electronically before Friday morning: I'll email you and link from here if it is!  The exam    Exam's  Problem 1 source
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HW answers for ch. 9
p. 482,  #3a)  Figure each file can end anywhere in its last page, and equally likely anywhere (a reasonable assumption if it's already gone on for some time).  Then the average endplace is at the middle, at 256K, leaving 256K unused per file.
3b) "Much smaller"--who knows?  Could be more than 256K unused per file  Or not..
3c) Percentages:  Bigger files would clearly have a smaller percentage unused--a 4+ page file would "waste" 1/2 of 1 of its 5 pages or about 10%.  Small files would waste 40 or 50 or 60% or more, each one wasting at least part of its page...
#4a) Each byte is addressible, 12-bit addresses = 212 = 4096 addresses.  b) If Physical memory (max.) of 16 frames uses all the memory, then frame size=page size = 4096/16 = 212/ 24 = 28 = 256 addresses = 256 bytes.  c) 8 bits are used to address the offset.  (So 4 bits are used to address the frames/pages).  d) For d assume the job can fill all of virtual memory.  So the job's page table needs as many entries as it has pages, max 16.  The non-empty entries can only be the max of the number of frames, here also 16.
After answering a,b,c,d do this:  Assume that Main memory has only 6 of the possible 16 frames.  (So the frames are the same size as in part b.)  What (if any) answers to a,b,c,d will be different (and how)? d) changes only if you want to know how many non-empty entries there can be.  Answer, 6.  What is the smallest and what is the largest Physical address in Main memory? 0000 0000 0000 to (the biggest value in the 6th frame) 0110 1111 1111 = 6FFH.
#6  The Not-dirty ones.
#10 (Assume 3 frames are available.  OPTimal algorithm)
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Amnesty extended farther:  Any  old "Programs" handed in  by Thursday noon, Dec. 14 will be only 1 day late.
 
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Notes:
Please fill out an evaluation,
return it to the ENVELOPE
circulating.  The envelope will be with Erna in the Dean of the Faculty's office, if you miss doing it today. (Will someone please deliver it there? Under the door is ok)
Look at the Debugger in C++:  In the lab.  Handout.
 
"Stepping" through a program, watching the variables.
Examining the "disassembled" assembly language and CPU.


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