Re: A82: ASH Routine

Re: A82: ASH Routine

• To: assembly-82@lists.ticalc.org
• Subject: Re: A82: ASH Routine
• From: "Thomas J. Hruska" <thruska@tir.com>
• Date: Fri, 10 Apr 1998 21:30:53 -0400
• Delivered-To: assembly-82-outgoing@towerguard.unix.edu.sollentuna.se
• In-Reply-To: <199804102313.TAA30800@camel8.mindspring.com>
• Reply-To: assembly-82@lists.ticalc.org

At 04:17 PM 4/10/98 -0700, you wrote:
>>    I need an ASH routine that will exit to ASH no matter how deep in
>>subroutines I am.  I know I can inc the sp register that many times and
>>then ret but this routine may be called from many different points in my
>>program and I won't know how many subroutines I will be in when it is
>>called.
>
>This works in CrASH too BTW.  This uses self-modifying code - if you
>don't understand it, don't worry about it.
>
>At very beginning of program:
>
>ld hl,0
>add hl,sp
>ld (SAVED_SP+1),hl
>
>...
>
>Then later:
>
>EXIT_2_CRASH:
>SAVED_SP:
>ld sp,0
>ret
>
>
>To return to CrASH, do jp EXIT_2_CRASH

This won't work for OShell-82/OS-82 unless you use PROGRAM_ADDR.  Here is a
modified routine using PROGRAM_ADDR:

At very beginning of program:

ld hl,0
add hl,sp
ld ix,SAVED_SP+1
ld de,(PROGRAM_ADDR)
add ix,de
ld (ix),l
ld (ix+1),h

...

Then later:

EXIT_2_OSHELL:
SAVED_SP:
ld sp,0
ret


To return to OShell-82/OS-82, do JUMP_(EXIT_2_OSHELL)

This is VERY unoptimized, but it does the same job if you want to port,
using this method, to OS-82.


                 Thomas J. Hruska -- thruska@tir.com
Shining Light Productions -- "Meeting the needs of fellow programmers"
         http://www.geocities.com/SiliconValley/Heights/8504
                    http://shinelight.home.ml.org

• Re: A82: ASH Routine
• From: mgp4007@omega.uta.edu (Michael Pearce)

• Re: A82: ASH Routine
• From: Barubary <darkstar_usa@pipeline.com>

• Prev: Re: A82: TI doesn't suck all batteries
• Next: Re: A82: Sound? & Assembly....
• Index(es):
  • Main
  • Thread