[Coco] Mod10 Suggestions

[William Astle]

You can replace CMPA #0 with TSTA to save one more byte.

Alternatively, you can start with A at 15 and not bother with the DECA 
at the start of the loop. Then replace your CMPA #0 with DECA and use 
BMI to branch if you've gone past 0 (negative). (DEC sets N (negative), 
Z (zero), and V (overflow) correctly. It just doesn't change C (carry))

On 2017-02-17 02:58 PM, William Mikrut wrote:
> Thank you for all of the great suggestion!
>
> I have implemented them and the byte count shrunk from 79 -> 65 ( Almost
> 20% reduction) and it actually runs faster without the excessive loop
> overhead.
>
> The only thing I didn't try was storing a variable in the DP ($0003)
> because I always want my code to be completely independent of there it's
> loaded.
>
> Here is the revised version 2!
>
> (A CoCo based CCD reader would be Awesome!
> I wonder if Ingenico would be on board!!)
>
>
>
> On Fri, Feb 17, 2017 at 4:34 AM, Mark McDougall <msmcdoug at iinet.net.au>
> wrote:
>
>> On 17/02/2017 5:57 PM, Dave Philipsen wrote:
>>
>> Here's a problem.  It's not the credit card digit itself that is being
>>> tested for odd/even.  It's the position of the digit.  So you need to do
>>> a  'bitb #1' instead of a 'bita #1'.
>>>
>>
>> Good catch - thanks!
>>
>> Regards,
>>
>> --
>> Mark McDougall
>> <http://retroports.blogspot.com.au>
>>
>> --
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>>
>>
>>
>>