[Coco] assembly language question.

[Arthur Flexser]

The example seems a bit unusual in that you're comparing a 16-bit quantity
(the X register) with an 8-bit one (due to the use of the 'less than'
sign).  I'm guessing that that would cause only the LSB of X ($FA) to be
compared to <$000A (=$0A) with the outcome that the BLO no branch since $FA
is greater than $0A by an unsigned comparison.

Art
On Wed, Feb 3, 2010 at 9:10 PM, Gene Heskett <gene.heskett at verizon.net>wrote:

> Greets all;
>
> I've read through the moto programmers manual for the 6809 for the cmp
> functions, and am still confused.  The cmp function is a subtract function
> where the answer is thrown away, only affecting the CC flags so that a
> following beq or blo will take the correct jump.  But somehow, it isn't
> clear
> which is subtracted from what.
>
> Given that regs.x contains $02FA, and that the integer memory location
> referenced by LblName contains $000A, will the blo take, or be ignored
> here?
>
>        cmpx  <LblName memory address in DP that holds the $000A above
>        blo     somewhere else
>
> Thanks.
>
> --
> 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)
>
> <cesarb> Damn, every time I spawn, qf-client-x11 locks hard
> <Zoid> Don't die?
> <Knghtbrd> good incentive.
>
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