[A83] Re: allocating uninitialized memory? + _insertmem
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[A83] Re: allocating uninitialized memory? + _insertmem
Actually.. with appvars you get the exact same result as with programs...
appvars and programs are exactly the same except that they have a different
identifier ... so that appvars don't appear in the programs list (and can't
be executed) and vice versa...
so if you were to port to 83, you would just change the name of the appvar
to something that is invisible to the programs list menu....and change the
object type to program.
Anyways ... I think this method of creating a variable big enought to hold
all the data is useful only in few circunstances... in most cases the
memory, going to be scratch memory will be used only in a contiguous part of
the program in which you will unlikely do stuff that will require the TIOS
allocating dea llocating memory and messing everything about ...
The only advantage of creating a var and storing the stuff there to operate
on is that you could allow to interrupt the process and continue later, or
at the smae time you process the data contained within you ABSOLUTELY HAVE
to do memory messing operations..(I think this is highly unlikely)... In
anyother case this method just created unwated overhead...
-Nicolas Gilles
----- Original Message -----
From: "Gavin Olson" <gtolson@comcast.net>
To: <assembly-83@lists.ticalc.org>
Sent: Saturday, May 31, 2003 14:37
Subject: [A83] Re: allocating uninitialized memory? + _insertmem
> At 09:10 AM 5/31/03 -0400, you wrote:
> >what about appvars??
>
>
> They make porting to 83 very difficult - with using the scratch space, you
> just have a #ifdef structure; with appvars you simply can't do it on the
83.
>
>
>
>
> >At 03:35 AM 5/31/03, you wrote:
> >
> >> > >It's still sloppy, though. You can't absolutely guarantee that
another
> >> > >program won't already exist with the same name - although you could
> >> > >manually
> >> > >check that, I suppose.
> >> >
> >> > That seems like a silly arguement. If your program is named Bingo,
say,
> >> > create a program named BINGODATA or whatever. Talking about
garantees
> >>isn't
> >> > going to get you anywhere, and you can't absolutely garantee that
there
> >>will
> >> > be free RAM space no matter what method you use. At least this way
you
> >>can
> >> > garantee that the system isn't going to scribble all over your data
> >>because
> >> > you put it into what is essentially scratch space.
> >> >
> >> >
> >> >
> >> >
> >>Well, who's to say that there isn't already a program on the calculator
> >>called "BINGODATA" (if programs could have 9 character names, that is)?
And
> >>besides, the only reason you would use this method that I can think of
would
> >>be to save data for future use. But then you run into troubles with
keeping
> >>data in sync - making sure that the user didn't delete the save program,
or
> >>whether it's archived or not etc. IMHO, it is generally better to use a
> >>shell that supports writeback or write the data back yourself when you
need
> >>to store vital data.
> >>
> >>Using the free RAM space for temporary buffers/lookup tables or whatever
is
> >>a cleaner method with a hell of a lot less overhead.
> >
>
>
>
>
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