[Coco] A way to recompile HDB-DOS with more fixed-address variable space

[Juan Castro]

That was only an experience, I'm going to steal much less. Probably no more
than 48 bytes.


On Mon, Feb 3, 2014 at 3:28 AM, Arthur Flexser <flexser at fiu.edu> wrote:

> There may be a few programs that are really shoehorned into memory that
> will give an 'out of memory' error if you steal 256 bytes from free memory,
> though I doubt there'd be very many of them.
>
> Art
>
>
> On Mon, Feb 3, 2014 at 12:18 AM, Juan Castro <jccyc1965 at gmail.com> wrote:
>
> > But that too is relocated automatically in the DECB init code. Its
> address
> > is in a variable (at $00BA). I compiled a ROM with a 256-byte higher
> DFLBUF
> > and it seems to run. See screenshot:
> >
> >
> >
> https://lh3.googleusercontent.com/-zUr0rqC3Q-Y/Uu8lg9w0sjI/AAAAAAAAFYM/ivDtf725M9M/s800/GraphicsRelocated.png
> >
> > Now, I can imagine some software COULD presume the address is "$600 if
> ECB
> > and $E00 if DECB". Which is bad, Bad, BAD. (Does any do?) Hey, even a
> > "FILES 10" will relocate the graphics area!
> >
> > By the way, yes, I'm using the cassette buffer as a variables area for
> now
> > but that will change.
> >
> >
> > On Mon, Feb 3, 2014 at 2:32 AM, Arthur Flexser <flexser at fiu.edu> wrote:
> >
> > > Long before you hit $2600, you'll run into the PMODE graphics area,
> which
> > > starts at $E00.
> > >
> > > Art
> > >
> > >
> > > On Sun, Feb 2, 2014 at 10:56 PM, Juan Castro <jccyc1965 at gmail.com>
> > wrote:
> > >
> > > > Redefine the DFLBUF constant, from the current $0989 to, say, $09B9
> if
> > I
> > > > need 48 bytes for my stuff. I realize I can't do that forever or I'll
> > > start
> > > > messing with the DOS command who needs addess $2600 to load the
> > > bootstrap.
> > > >
> > > > Could I expect some nasty side-effect from some software if I do
> that?
> > > >
> > > > (In other news, I'm going to listen to the sage advice recently
> > > dispensed,
> > > > abandon that "detect signature" scheme and just use conditional
> > assembly
> > > > for 16K ROMs.)
> > > >
> > > > Juan
> > > >
> > > > --
> > > > Coco mailing list
> > > > Coco at maltedmedia.com
> > > > http://five.pairlist.net/mailman/listinfo/coco
> > > >
> > >
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> > >
> >
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> >
>
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