[Coco] Memory Map

[John W. Linville]

On Wed, May 08, 2013 at 09:18:02AM -0400, Louis Ciotti wrote:
> Actually I want to be able to use lwasm, or even as09 rather than on the
> CoCo.
> 
> So using lwasm the listing below does not work in XRoar with DECB 1.1 rom:
> 
>          org    $2000
> begin    jmp    start
>          fdb    done-begin
> start    lda    #$f9
>          ldx    #$400
> screen   sta    ,x+
>          cmpx   #$600
>          bne    screen
> wait     jsr    [$a000]
>          beq    wait
>          swi
> done     equ    *
>          end
> 
> This listing works, but when I press a key nothing happens (I figured it
> would return to DECB when a key is pressed)
> 
> begin    jmp    start
>          fdb    done-begin
> start    lda     #$f9
>          ldx    #$400
> screen   sta    ,x+
>          cmpx    #$600
>          bne    screen
> wait     jsr    [$a000]
>          beq    wait
>          swi
> done     equ    *
>          end
> 
> Again this is with lwasm

What do you think the swi does?  I'm not aware of any use of it for
DECB, but I don't go "way back" as a CoCo assembly programmer...

I would have thought that you would use an rts there instead?

John
-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.