CS 353 -- Fall 06 -- Lab 5: Writing PC-231 Programs
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Write up programs in PC-231 assembly language to solve the following problems.
Try to use comments, if for no other reason to show that you understand how the
assembler handles them (remember, you'll be writing an assembler of your own soon).

You should be able to access the assembler (asm231) and simulator (sim231) using
your hydra unix account (run "telnet hydra" from the Windows Start menu, use "un"
to get out of the menu system if necessary, then issue the asm231 or sim231 commands
as shown in class). You can keep your program in an editor window and just paste 
it in after changes (remember to use "Control-D" to signal end of input).

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1. Read in 5 numbers (in decimal) and print out the minimum (first) and
   maximum (second) values, again in decimal. You may assume all the numbers
   are non-negative, if that helps. (You might start off with two numbers, 
   then three, before you generalize to five.)

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2. Read in 15 letters (in ASCII) and print them out in reverse order. You will
   need to save and retrieve them in RAM, using the LOAD and STORE operations.
   Look at the sample programs (e.g., the one which writes out a string from RAM)
   for ideas on how to do this. Note that you will *not* need to store the 
   characters as part of the "program" using CONST pseudo-instructions, since 
   you will be reading them in from input.

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3. Read in a decimal integer n representing the order of a polynomial (e.g., 2 
   for a quadratic), then read in n+1 coefficents (some of these might be 0). 
   Finally, repeatedly read in numbers to be used for the value of the "unknown" 
   (x) in the polynomial, and print out the value of the polynomial as a whole. 
   Stop the program when a 0 value is given for the unknown.
   
   For example, if you read in 2, then 3 4 5, your polynomial is:
   
   	3x^2 + 4x + 5
   	
   and its value at various x's is:
   
   		1	=>	12
   		2	=>	25
   		3	=>	44
   		4	=>	69
   		0	=>	stop the program

   NOTE: you should use as efficient a method as possible for evaluation of your
   polynomial: work from left to right, multiplying by x and adding the next
   coefficient as you go.
   
   NOTE: this is partly a test of your ability to sketch out a program with several
   loops and "function calls" (for the multiplication), so draw flowcharts or
   write pseudo-code first.

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4. Read in a string of ASCII letters (you don't have to check that they *are*
   letters), terminated by a period ('.') and use bubble sort to sort them
   in increasing order. (If you use mixed cases in your input, the ASCII values
   of all the uppercase letters are lower than the lowercase ones, so you'll 
   see the capitals first.) 

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