CPS104			Exam 1			Oct 12, 2000

1. Write a sequence of 4 SPIM conditional branch instructions which 
tests the ASCII code C in register $t0, and branches to NL if C 
represents a non-letter, to LC if C represents a lower case letter, 
and "falls through" if C represents an upper-case letter.  Your 
program can use SPIM pseudo-instructions, like "beq $t0, 33, NL", 
which branches to NL if R[$t0]==33.  For convenience, 'a'==97, 
'z'==122, 'A'==65, and 'Z'==90.

2. Write code equivalent to the SPIM instruction "lbu $t0, CHAR($t1)", 
where "CHAR" is a label for location 0x18003:
	a. in MYMIPS assembly language
	b. in basic MIPS (no pseudo-instructions) assembly language

3. Convert each of the following numbers to single precision floating 
point representation, showing the steps of your work, and ending 
with hexadecimal representations for each of them: 
	a. 0.75
	b. -2.25

4. Write an RMI program which, given integers in variables A and B, 
sets variable C to 1 if bits 29 of both A and B are 1, and sets C to 
0 otherwise.  Do not use any constants larger than 100 in magnitude 
in this program.  Of course, it should run quickly, as well (less 
than 30 basic RMI instructions).

5. Write a SPIM program to solve the same problem as in question 4, 
allocating space for variables A, B and C in memory properly.  Your 
program should be a complete SPIM program, including the proper 
directives.  The program should include a "main" procedure which returns 
properly.  The program should execute as quickly as possible.