Assembly language help

[mikeeginger]

For part of my college  course I have to do some assembly language programming
how ever I am finding it hard to under stand how the changes i make relate to the program
I am trying to write  which is to control a set of traffic lets in a virtual environment
 
are they any good guides or can some one help explain how to work out how
the numbers i put in relate to lights turning on or not
 
the program I have written pasted below in plain text

the assembler i am using is sms32V5

 

 

Start:

 

MOV AL,55 ; 01010101

OUT 01 ; Send the data in AL to Port 01 (the traffic lights)

MOV AL,AA ; 10101010

OUT 01 ; Send the data in AL to Port 01 (the traffic lights)

 

MOV AL,56

OUT     01

MOV AL,AA

OUT 01

 

MOV AL,57

OUT 01

MOV Al,AA

OUT 01

 

MOV  AL,58

OUT 01

MOV AL,AA

OUT 01

 

MOV AL,60

OUT 01

MOV AL,AA

OUT 01

 

MOV  AL,65

OUT 01

 

MOV AL,AC

OUT 01

MOV Al,AC

 

 

[prolemur]

I was watching a YouTube for c++ and he also had about 50 x64 assembly tutorials, I thought they were great.

http://www.youtube.com/user/WhatsACreel/videos

[Gronnie]

I don't see anything attached?

 

I just took an assembly class so I am no expert, but I did get an 'A' and can try to help.

[mikeeginger]

I don't see anything attached?

 

I just took an assembly class so I am no expert, but I did get an 'A' and can try to help.

Sorry i thought i attached the file the code is posted in plain text

[Flojer0]

The tricky skill that you will need programming in any language and is especially hard to have with assembly is the ability to think of your program in a much higher and more abstract level then your code. For example in this program you could simply think of it as what light you are trying to turn on or off at a given moment. When you understand the problem you are trying to solve then it becomes much easier to work with the code and if done well can make the code feel too easy.

[jam08060]

So with assembler you are directly manipulating memory, so with the code above you are worried about the data being stored in accumulator AL.  This is because your OUT function takes the value of AL and sends it to the traffic lights.

 

So, with that said... All your code above is doing is storing new decimal values (55, 56, 57, 58, 60, 65) into the accumulator AL and transmitting each of those values to the traffic light.

 

From your code and the hardware you would be working with I'm not entirely sure what AA is, but it doesn't really seem to matter as it is only ever resetting the value inside AL and then being transmitted to the traffic lights, so i'd assume its probably a memory location (accumulator / register) that stores a reset or value that represents an off state... just a guess...

 

So the main thing you need to worry about is what values you will be storing in accumulator AL to then send using the OUT instruction to the traffic lights.

 

This should get you started, although it is a bit tricky to really give you a definitive guide without more context...

 

Hope this helps!

[mikeeginger]

Thank you to all for the help

 

Manged to sort out the problem by finding a conversion table and using notes I had

 

ps how do i close the thread?

[rashdanml]

You don't, you let the thread sink into oblivion. 

 

(Could also select Best answer and leave it at that).