Re: A86: Re: _exec_basic and _findAlphaUp


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Re: A86: Re: _exec_basic and _findAlphaUp




and what happens if the user tries to run the shell from the actual
assembly program instead of the loader?  Chaos?  Great.



Robin Kirkman wrote:
> 
> It's a basic program that is run instead of the actual assembly code to
> start the shell.
> 
> Example:
> 
> ------------
> Lbl 1
> ::::::::
> Asm(ShelName)
> If Ans==1:Goto 1
> Return
> ------------
> 
> The shell ShelName can run assembly programs by itself easily. However,
> to run a basic program, the shell must do some more complicated stuff:
> 1) Set Ans to 1. Use those funky op routines.
> 2) Modify the basic program in RAM, so that :::::::: is replaced with
> the BASIC program (Ex: :::::::: -> BProg:::)
> 3) Quit. Yes, the shell quits.
> 
> The shell quits, and since Ans = 1, it jumps to the ::::::::, which is
> now BProg:::
> The TIOS runs BProg and -doesn't- crash ;)
> The shell is started again.
> 
> For the shell to exit, it just sets Ans to zero and quits.
> --robin
> 
> Cassady Roop wrote:
> >
> > Hold on, just what exactly does that mean?  What is a BASIC loader?
> >
> > Kirk Meyer wrote:
> > >
> > > The problem with _exec_basic is one that has been known for quite some time,
> > > and this is why any good shell uses a BASIC loader and runs BASIC programs
> > > from BASIC - simply because they won't work otherwise.
> > >
> > > ----- Original Message -----
> > > From: Cassady Roop <croop@oregontrail.net>
> > > To: <assembly-86@lists.ticalc.org>
> > > Sent: Wednesday, December 08, 1999 7:56 PM
> > > Subject: A86: _exec_basic and _findAlphaUp
> > >
> > > > When I use _exec_basic to run a basic program, it runs perfectly but for
> > > > one problem:  if the basic program has a STOP command at the end,
> > > > instead of a RETURN or nothing at all, it crashes the calculator
> > > > totally.  Is this a bug in _exec_basic or am I not passing something to
> > > > the routine that I should be?  I am passing in the name to run in OP1;
> > > > I thought that was all it needed.  I have ROM 1.3.  Can anyone duplicate
> > > > this?


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