So far i have made a code that add 2 numbers but they are single digits.
.orig x3000
lea r0, string1
puts
getc
out
add r1, r0, 0
ld r0, minus48
add r1, r1, r0
lea r0, string1 ;input one
puts
LOOP
getc
out
add r2, r0, 0
ld r0, minus48
add r2, r2, r0
add r3, r1, r2
out
OUTSIDE
lea r0, string2 ;input two
puts
ld r0, plus48
add r0, r3, r0
out
HALT
plus48 .FILL 48
minus48 .FILL -48
string1 .stringz "\nPlease enter a number: "
string2 .stringz "\nSum is: "
.end
and this works fine however I've been trying to make the number input store more then 1 digit and this is what I've done:
.orig x3000
lea r0, string1 ;input one
puts
LOOP
getc
out
add r1, r0, 0
brz OUTSIDE
ld r0, minus48
add r1, r1, r0
out
brnzp LOOP
lea r0, string1
puts
getc
out
add r2, r0, 0
ld r0, minus48
add r2, r2, r0
add r3, r1, r2
out
OUTSIDE
lea r0, string2 ;input two
puts
ld r0, plus48
add r0, r3, r0
out
HALT
plus48 .FILL 48
minus48 .FILL -48
string1 .stringz "\nPlease enter a number: "
string2 .stringz "\nSum is: "
.end
I have tried to use a loop so I can input more then single digits and the sum can calculate up to 9999. But my loop outputs weird characters but it doesn't run like I want it, LC3 is pretty confusing like it took me forever to get the addition of single digits, so help will be very much appreciated.
I didn't look over all of your code in detail but I'm a little confused about this first loop.
LOOP
getc
out
add r1, r0, 0
brz OUTSIDE
You're taking the ASCII char and adding 0 to check if our ASCII char is null, but you can't get a null char from the user.
ld r0, minus48
add r1, r1, r0
out
brnzp LOOP
These next few lines will also need to be modified. Basically when these 9 lines are run you are taking a char from the keyboard converting that ASCII value to an integer, then adding that int to its ASCII value. That's why you're getting a never ending loop of random char.
I would recommend having several variables for each base 10 value.
Example:
; Stored values
NUM1_1 .FILL x0000 ; stores the last number entered by the user
NUM1_10 .FILL x0000 ; stores the 10's value
NUM1_100 .FILL x0000 ; stores the 100's value
NUM1_1000 .FILL x0000 ; stores the 1,000's
So if you where given the number 5,382 by the user you would store 5 into NUM1_1000, 3 into NUM1_100, ect... and then add digit of the two numbers separately.
Or it might be easier to have a look up table that helps you add the base 10 values as the user types them in.
Example:
LookUp10 .FILL #0
.FILL #10
.FILL #20
.FILL #30
.FILL #40
.FILL #50
.FILL #60
.FILL #70
.FILL #80
.FILL #90
LookUp100 .FILL #0
.FILL #100
.FILL #200
.FILL #300
.FILL #400
.FILL #500
.FILL #600
.FILL #700
.FILL #800
.FILL #900
Then you can just use the number given to you by the user as an index for the value in the array you want.
