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

Juan Castro jccyc1965 at gmail.com
Mon Feb 3 00:18:56 EST 2014


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
> >
> > --
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> > Coco at maltedmedia.com
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> >
>
> --
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