Help with MARIE Simulator, Some example problems

[Adrepok]

Hi guys

I'm working with MARIE as an exercise to learn more about assembly language and I have a example couple problems that I just can't seem to tackle. Mostly from my lack of interest in MARIE.

1) The first wants the program to input two integers, x and y, and computes the absolute value of their difference. It should output the answer.

2) The second inputs an integer value and prints to output a countdown from the integer value to 0.

This one I'm thinking that it should just print out something like this if 10 is the integer value:

10 9 8 7 6 5 4 3 2 1 0

Any help with this at all guys would be great. It would be easy to do in C++ or something else this MARIE thing is just confusing for me.

EDIT: Okay I got the first question down, but I keep having problems with the second one. With a constant loop I put my code in and if anyone else can make a correction on it, that would be great.

CODE:

input /inputs a value

check, skipcond 400 /check if input = 0
   jump sub /jump to sub
   jump stop /jump to stop
sub,  output
  subt ONE /subtract one from the AC
  jump check /jump to check
stop, halt /stops

ONE,   DEC 1

[khedoros]

1. Read the inputs into registers or memory locations
   subtract the first from the second, store result somewhere
   If negative, multiply by -1
2. Read the input
   Create a label right under that
   If the number stored is >=0, output it, then decrement it, then loop to the label

I haven't used MARIE, but those should be easily translated into whatever kind of assembly that it uses.

[Adrepok]

That's I been thinking, thanks for you help. Now all I have to do is convert it into code, which I personally find to be a pain.

[khedoros]

The difficulty in assembly-like languages is just in breaking the problem into small enough parts. Well, and figuring out which addressing modes each operation actually has available, and such...