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

[Dave Philipsen]

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
>