[Coco] assembly language question.

[Gene Heskett]

On Thursday 04 February 2010, Bob Devries wrote:
>ok,... another quote:
>
>The assembler automatically selects direct addressing mode if the
> high-order byte of the address matches its internal "direct page." This
> direct page is not the same as the run-time direct pager register; it is
> an assemble-time value. You ordinarily set it to zero, but you can change
> it with the SETDP directive.
>
>/quote
>From the OS-9 Level 1 assembler manual.
>
>Regards, Bob Devries

And this particular code enters its driver routines with a routine that 
transfers the high byte of U to the DP, hence the ability to use the faster 
DP accesses for all of its housekeeping needs.  Something I didn't make clear 
at first.

-- 
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)

Maybe we could paint GOLDIE HAWN a rich PRUSSIAN BLUE --