[Coco] Optimizing 6809 Assembly Code: Part 2 – Speedup Storing Data – Unrolling Loops

[Glen Hewlett]

Cool Dave,

I’ll probably use both examples just to make it clearer.  The more examples the better.  Of course I will give credit to you for the tricks.

Thanks,
Glen

> On Sep 15, 2017, at 11:11 PM, Dave Philipsen <dave at davebiz.com> wrote:
> 
> Another example of this might be calling a subroutine which positions the cursor on the screen.
> 
> Instead of:
> 
> ldd   #$0101      A=1 (x coord), B=1 (y coord)
> jsr   curXY       position the cursor
> lda   #$??        continue with program
> 
> do this:
> 
> jsr   curXY       position the cursor, X and Y are pointed to by the program counter
> fdb   #$0101 A=1 (x coord), B=1 (y coord)
> lda   #$??        continue with the program
> 
> 
> 
> Dave
> 
> 
> On 9/15/2017 9:44 PM, Glen Hewlett wrote:
>> Hi Again,
>> 
>> I just posted Part 2 of my series of blogs about optimizing 6809 assembly language programs.
>> 
>> https://nowhereman999.wordpress.com/2017/09/15/optimizing-6809-assembly-code-part-2-speedup-storing-data-unrolling-loops/ <https://nowhereman999.wordpress.com/2017/09/15/optimizing-6809-assembly-code-part-2-speedup-storing-data-unrolling-loops/>
>> 
>> Cheers,
>> Glen
>> 
> 
> 
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