Re: A86: Memory Lock


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Re: A86: Memory Lock






Stephen Hicks wrote:

> i'm not sure if this applies to anything, but here it goes:
>
> earlier, you said that the demo program loads ($d625) into a.  this restores the a
> register from before [sqrt]key is called (using the asm modules routines, posted
> long long ago), which probably is how you can make sure that the a register holds
> the result from _getky.  if you want to trick the calc into thining a different
> key was pressed, you might need to load a back into ($d625)...?

Right.  It puts the keypress into a.  But you don't need put it back; when a module is
finished, the registers and flags are carried back to the calling program.  That's the
idea behind the memory lock:  check for a certain keypress and xor the a register if
it was pressed (so that the OS won't know it was pressed).  And similairly, to create
a "secret" key, put $09 (Enter) into the register so that calc will think Enter is
pressed.:-)

>
>
> Dux Gregis wrote:
>
> > It should be pretty simple.  Just put $09 into the register if that secret key
> > is pressed.  (Since the delete state uses _getkey, the "secret" key can use
> > alpha or 2nd.)
> >
> > Trey Jazz wrote:
> >
> > > o ok...btw have you tried to add a 'secret' key that when u press it should
> > > let you delete variables? i tried but the calc wouldnt let me still :)
>
> --
> Stephen Hicks
> mailto:shicks@mindspring.com
> UIN:5453914
> AIM:Kupopo1




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