Write an ASSEMBLY program to generate 30 random integers bet

Write an ASSEMBLY program to generate 30 random integers between 0 an 990. Print the random numbers diagonally on a light-green screen.

Solution

# it will generate 30 random numbers between 0 and 990

.data
# Create a string to separate the numbers with a space
spacestr:    .asciiz \" \"

.text
##############################################################################
# seed the random number generator
##############################################################################

# get the time
li   $v0, 30       # get time in milliseconds (as a 64-bit value)
syscall

move   $t0, $a0   # save the lower 32-bits of time

# seed the random generator (just once)
li   $a0, 1       # random generator id (will be used later)
move    $a1, $t0   # seed from time
li   $v0, 40       # seed random number generator syscall
syscall

##############################################################################
# seeding done
##############################################################################

# generate 30 random integers in the range [0-990] from the
# seeded generator (whose id is 1)
li   $t2, 29   # max number of iterations + 1
li   $t3, 0       # current iteration number

#   #   #   #   Start Loop   #   #   #   #   #
LOOP:

li   $a0, 0       # as said, this id is the same as random generator id
li   $a1, 990       # upper bound of the range range is [0-990]
li   $v0, 42       # random int in range, service
syscall

# $a0 now holds the random number
# lets add one to make the range [0-990]
addi   $a0, $a0, 1

# loop terminating condition
addi   $t3, $t3, 1   # increment the number of iterations
beq   $t3, $t2, EXIT   # branch to EXIT if iterations is 10

# $a0 still has the random number
# print it
li   $v0, 1       # print integer syscall
syscall

# print a space
la   $a0, spacestr   # load the address of the string (pseudo-op)  
li   $v0, 4       # print string syscall
syscall

# Do another iteration
j   LOOP

##############################################################################
# Tell MARS to exit the program
##############################################################################
EXIT:
li   $v0, 10       # exit syscall
syscall