Atari ST Machine Language 68000

[ftovar]

Does anybody else have this book by Abacus Software? I think I need help on page 12 or is this just a typo on their part? The part where they add two binary numbers

0110

1011

10001 and then get the answer on parenthesis, they have 6 + 11 =17.

 

Should it not be 16 + 1? The end result is 17.

 

Also on the multiplication part I understand how they get 1000010 when they multiply 0100 * 1011 but again the parenthesis throws me off. They have 6 * 11 = 66. I thought you still had to just add the end result. I get 64 + 2 = 66. The end result is still 66. Is there something I am not doing right here to verify the end result?

 

Thanks

[Cybergoth]

Hi there!

 

The part where they add two binary numbers

 0110

 1011

10001  and then get the answer on parenthesis, they have 6 + 11 =17.  

 

Should it not be 16 + 1? The end result is 17.

 

The binary end result transfered to decimal is in fact 16+1=17, but the actual addition was 6 + 11 = 17.

 

Also on the multiplication part I understand how they get 1000010 when they multiply 0100 * 1011 but again the parenthesis throws me off. They have 6 * 11 = 66.

 

Same here. In the parenthesis you get the complete multiplying operation, and not a binary to decimal conversion.

 

Greetings,

Manuel

[ftovar]

That is what is throwing me off. How did they get 6 + 11 if we are trying to convert binary to decimal. The same with the multiplication. 6 * 11. I can't seem to understand how they get those numbers when we are using the 1 * 2 to the power or 0 * 2 the power then add the numbers to get the end result. What am I missing here? I know it's probably simple but it's got me confused. Geez and I'm barely on page 12.

 

Thanks

[Cybergoth]

Hi there!

 

That is what is throwing me off.  How did they get 6 + 11 if we are trying to convert binary to decimal.  The same with the multiplication. 6 * 11.  I can't seem to understand how they get those numbers when we are using the 1 * 2 to the power or 0 * 2 the power then add the numbers to get the end result.  What am I missing here? I know it's probably simple but it's got me confused.  Geez and I'm barely on page 12.  

 

To sum it up in one line:

 

0110 + 1011 = 10001 in binary equals 6 + 11 = 17 in decimal.

 

So what is your problem with that?

 

Greetings,

Manuel

[ftovar]

Ahh I see where I made my mistake. 1.) I did not read the book correctly. 2.) I did not read your post correctly either. You did clarify my question and explained that it's straight binary addition and multiplication with NO conversion to decimal. However, this is where I get confused. Where as converting to decimal you would 1 x 2^4 + 0 x 2^3 , etc. How do you read/add the end result 10001 to equal (6 + 11). This is where I do not see the answer. Example on Page 10, the Binary number 0101 is abbreviated, etc. This is what confuses me.

 

Thanks for answering and helping a newbie out.

[ftovar]

Tsk, Tsk, Tsk. Why didn't the book just tell me that they converted 0110 to decimal 6 and 1011 to decimal 11. The reason I was confused was because they had (6 + 11) next to the final answer of 10001 with no explanation that it was assumed.

 

I totally understand it now.

 

Thanks to all who helped out and on to the next chapter.