Re: A86:ret

To: assembly-86@lists.ticalc.org
Subject: Re: A86:ret
From: "Andrew T" <ironman_294@hotmail.com>
Date: Wed, 20 Oct 1999 03:23:01 GMT
Reply-To: assembly-86@lists.ticalc.org





>From: "David Phillips" <david@acz.org>
>Reply-To: assembly-86@lists.ticalc.org
>To: <assembly-86@lists.ticalc.org>
>Subject: Re: A86:ret
>Date: Tue, 19 Oct 1999 00:34:50 -0600
>
>
>Just like writing a "perfect" dissassembler would be impossible without
>running the code or incredible AI (as smart as a human), there would be no
>way to tell.  Have to run it and see if it crashes.  A program doesn't have
>to end with a physical ret, either -- it just has to return to the OS.  
>Like
>a <jp _clrLCD> would be the same as <call _clrLCD \ ret> but be a byte
>shorter.  Run it in VTI and see if it crashes.
>
>What kind of people would do that, anyway?
>
> > I learned the hardway that things don't work if you don't put a "ret" at
>the
> > end of a program, but does anyone know if there are any programs that 
>can
> > tell me if an asm program doesn't have an ret? (I know a few people who 
>do
> > this to existing programs to turn them into viruses.)
>
>
>
Could also say <pop hl / call _clrLCD> but <jp _clrLCD> is still smaller.  
You could also test it on a EMU to see if its going to crash your CALC.

-Andrew

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

Follow-Ups:

Re: A86:ret

From: "David Phillips" <david@acz.org>