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# Program #2: Check Book 
# Programmer: Bob Britton
# Last Modified: Sep 30, 2008 Bob Farnham to format pseudocode as a 
# 	while loop.
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# Functional Description:
# This program can be used to balance your check book.
# <DESCRIBE YOUR OVERFLOW FEATURE HERE (IN ENGLISH) >
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# Pseudocode:
# 1. Print Header;
# 2. balance <- 0;
# 3. done <- false;
# 4. while( not done ), do the following steps:
#    4.1. Prompt user for transaction value;
#    4.2. Receive value from user;
#    5.4. if( value == 0 )
#    5.4.1  done <- true;
#    5.4.2  otherwise do the following steps:
#    5.4.2.1. balance <- balance + value;
#  <INSERT PSEUDOCODE FOR OVERFLOW DETECTION ALGORITHM HERE>
#	print the value of balance on the screen
# 5. print "Adios Amigo" on the screen
# 
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# Register Usage:
# $v0: Transaction Amount
# $s0: Current Bank Balance
#	<HERE YOU DECLARE ANY ADDITIONAL REGISTERS USED>
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	.data			# Data declaration section
Head: 	.ascii	"\n\tThis program, written by <YOUR NAME>,"
	.ascii	" can be used to balance your check book."
	.asciiz	"\n\n\t\t\t\t\t\t\t\t\t  Balance"
tabs:	.asciiz	"\t\t\t\t\t\t\t\t\t"
tran:	.asciiz	"\nTransaction:"
bye:	.asciiz	"\n  ****  Adios Amigo  **** "

	.text			# Executable code follows
main:
	li	$v0, 4		# system call code for print_string
	la	$a0, Head		# load address of Header message into $a0
	syscall			# print the Header

	move	$s0, $zero		# Set Bank Balance to zero
loop:
	li	$v0, 4		# system call code for print_string
	la	$a0, tran		# load address of prompt into $a0
	syscall			# print the prompt message

	li	$v0, 5		# system call code for read_integer
	syscall			# reads the amount of  Transaction into $v0

	beqz	$v0, done		# If $v0 equals zero, branch to done
	addu 	$s0, $s0, $v0	# add transaction amount to the Balance

	li	$v0, 4		# system call code for print_string
	la	$a0, tabs		# load address of tabs into $a0
	syscall			# used to space over to the Balance column
	
	li	$v0, 1		# system call code for print_integer
	move	$a0, $s0		# move Bank Balance value to $a0 
	syscall			# print Bank Balance
	b 	loop		# branch to loop

done:	li	$v0, 4		# system call code for print_string
	la	$a0, bye		# load address of msg. into $a0
	syscall			# print the string

	li	$v0, 10		# terminate program run and
	syscall			# return control to system

				# END OF PROGRAM