[Coco] assembly language question.

Gene Heskett gene.heskett at verizon.net
Thu Feb 4 00:00:39 EST 2010


On Wednesday 03 February 2010, Bob Devries wrote:
>Gene,
>
>the orientation of the < is importnat of course, and will determine the 8
> or 16 bit operation.
>
>To compare the X register with memory, it would need to read:
>
>cmpx >LblName
>
>Regards, Bob Devries

I don't believe so Bob.  If you are looking at page 2-2, section 2.2.4 
DIRECT, that book I have assumed for the 24 years that I've owned it, is 
erroneous.  Note that they used the same right arrow to note EXTENDED 
addressing in 2.2.3 immediately above, and since I know the right arrow > 
means extended, the left < arrow must then mean DIRECT.  And it assembles to 
$9C, offsetbyte.  I believe the notation in the level one assembler manual is 
correct.  Lack of an arrow generally means to load or cmp the immediately 
following byte or int, depending on the size of the register.

Simply put, they cannot use the exact same nemonic syntax for 2 completely 
different operations.  It doesn't grok.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

Book: "It's not your way."

Mal: "I have a way?  Is that better than a plan?"
				--"Serenity"



More information about the Coco mailing list