Reminder of the first assignment, due in 21st September 2000.

The assignment is to write a program that simulates part of the virtual
memory system in order to count the number of page faults that would be
caused by a particular program running.

The input to your program should just be a list of numbers. The first
gives the number of entries available in the page translation hardware,
the others are the sequence of virtual page numbers that the program
accesses when it runs (so you don't have to deal with a real program in
any way) The output should be just two lines, one saying how many page
faults there would have been if the FIFO page replacement strategy had
been used, the other saying the number for the LRU page replacement
strategy. For extra credit you can also calculate the numbers for Random
and Optimal page replacements.

For example, suppose the following program is loaded into memory starting
at address 600, and is about to run:

                   LOAD  1030
                   ADD   2051
                   ADD   1040
                   STORE 2066

(LOAD  n    means read the contents of memory location n into the
            accumulator)
(ADD   n    means add the contents of memory location n to the
            value already in the accumuator)
(STORE n    means store the value that is in the accumulator into
            memory location n)

Each of the program's four instructions are in page 1 (512-1023)
loactions 1030 and 1040 are in page 2 (1024-1536), and locations
2051 and 2066 are in page 4 (2048-2560).

So, the sequence of virtual page accesses for the example program are:
    first page 0 (to read the first instruction)
     then page 2 (to read location 1030)
     then page 0 (to read the second instruction)
     then page 4 (to read location 2051)
     then page 0 (to read the third instruction)
     then page 2 (to read location 1040)
     then page 0 (to read the last instruction)
  finally page 4 (to write into location 2066)

If the hardware in use had only three entries in its page translator, the
input to your program would be presented as:

      3 0 2 0 4 0 2 0 4

(if you are not happy with reading an indeterminate number of numbers, it
is OK to insist that a special value, such as -1 or "end" appears at the
end of the list, but your program must warn users of this requirement when
it is run)

The output from your program, for this example input should be
something very much like:

      Number of page faults using FIFO = 3
      Number of page faults using LRU  = 3

Don't just test your program with this little example!