Question

Im having issues with this project, I keep geting errors and idk why.

here are the instructions for the project:

"Create  "simple integer calculator using the MARIE computer.
The program should execute as follows:
Using the INPUT instruction wait for the user to enter a decimal number.
Using the INPUT instruction wait for the user to enter a second decimal number.
Using the INPUT instruction wait for the user to enter the character +, - or *.
Perform the desired addition, subtraction or multiplication operation.
Store the result in a variable in memory.
Display the result via the OUTPUT instruction.
The multiply can be done by repeated additions. For example, 12 * 3 would be calculated as 12 + 12 + 12."


What I have so far:

INPUT
Store X
INPUT
Store Y
INPUT
Store c
Subt 43
/ Skipcond can be used here if c<0 then its Multiplication , if c=0 then its Addition , if c>0 then its substraction
loop,Load num
Add X
Store num
Load Y
Subt one
Store Y
Skipcond 400
Jump loop /no
Load num
Output
Halt/Declarelabelshere
X, DEC 0
Y, DEC 0
one, DEC 1
num, DEC 0
c, DEC 0
A, DEC 42
B, DEC 43
C, DEC 45


what I get when I run:

Assembly listing for: Calc project.mas
                Assembled: Tue Oct 13 17:14:46 CDT 2020

000 5000 |         INPUT             
001 2012 |         STORE X           
002 5000 |         INPUT             
003 2013 |         STORE Y           
004 5000 |         INPUT             
005 2016 |         STORE c           
006 4043 |         SUBT 043          
         |                          / Skipcond can be used here if c0 then its Multiplication , if c=0 then its Addition , if c>0 then its substraction
007 ???? |  loop   NUM               
   **** Instruction not recognized.
   **** Missing operand.
008 3012 |         ADD X             
009 2015 |         STORE num         
00A 1013 |         LOAD Y            
00B 4014 |         SUBT one          
00C 2013 |         STORE Y           
00D 8400 |         SKIPCOND 400      
00E 9007 |         JUMP loop        /no
00F 1015 |         LOAD num          
010 6000 |         OUTPUT            
011 7000 |         HALT             /Declarelabelshere
012 0000 |  X      DEC 0             
013 0000 |  Y      DEC 0             
014 0001 |  one    DEC 1             
015 0000 |  num    DEC 0             
016 0000 |  c      DEC 0             
017 002A |  A      DEC 42            
018 002B |  B      DEC 43            
019 002D |  C      DEC 45            

2 errors found.  Assembly unsuccessful.

         SYMBOL TABLE
         --------------------------------------------------
          Symbol | Defined | References 
         --------+---------+-------------------------------
          A      |   017   | 
          B      |   018   | 
          C      |   019   | 
          X      |   012   | 001, 008
          Y      |   013   | 003, 00A, 00C
          c      |   016   | 005
          loop   |   007   | 00E
          num    |   015   | 009, 00F
          one    |   014   | 00B

Answer 1

Greetings!!

Code:

            INPUT                         /READ X

            STORE X                    /STORE X

            INPUT                         /READ Y

            STORE Y                    /STORE Y

            INPUT                         /READ DECIMAL VALUE OF OPERATOR

            STORE C                    /STORE OPERATOR

            SUBT OP                    /SUBTRACT 43

            SKIPCOND 800         /CHECK AC>0, THEN MUL           

            JUMP ADSUB            /ELSE ADSUB

            JUMP MUL   

ADSUB,          SKIPCOND 000/AC<0, THEN SUB

            JUMP ADD                /ELSE ADD

            JUMP SUB

ADD,   LOAD X                     /ADDITION

            ADD Y

            STORE ANS               /STORE ANSWER

            JUMP OUT                 /DISPLAY

SUB, LOAD X                     /SUBTRACTION

            SUBT Y

            STORE ANS               /STORE ANSWER

            JUMP OUT                 /DISPLAY

MUL, LOAD Y                     /LOAD MULTIPLIER

            SUBT ONE                 /MULTIPLIER - 1

            STORE Y                    /SAVE

            LOAD ANS                /LOAD ANS

            ADD X                        /REPEATED ADDITION

            STORE ANS

            LOAD Y                     /LOAD MULTIPLIER

            SKIPCOND 400         /IF MULTIPLIER IS 0,THEN LOAD ANSWER

            JUMP MUL                /ELSE REPEAT ADDITION

            LOAD ANS                /LOAD ANS OR DISPLAY

OUT,   OUTPUT

            HALT

X,        DEC 0

Y,        DEC 0

C,        DEC 0

OP,      DEC 43

ONE,   DEC 1

ANS,   DEC 0

Output screenshots:

Addition:34+45=79

Subtraction: 78-67=11

Multiplication: 23 x 15 = 345

Hope this helps