From: Ullrich von Bassewitz (uz_at_musoftware.de)
Date: 2001-08-12 20:07:35
Hi!
On Sun, Aug 12, 2001 at 04:12:04PM +0200, groepaz wrote:
> so what does that mean as a consequence then.... i guess the way it is
> then is that all ram under kernal and i/o ($d000-$ffff) is currently
> unused in a c64 setup ?
Yes. However, several library routines expect the kernal ROM and I/O to be
banked in, so you cannot change this without some effort.
> or do library calls that use the kernal bank
> the memory as needed?
No. The kernal is expected to be banked in. The kernal is not only called
directly by several library routines, the kernal interrupt handler, keyboard
handling, ..., is also used. One could use the memory below I/O and kernal for
some special purpose, but this is not portable and there is no library support
for this.
> (which leads to another question... IF that is
> the case, it would be more or less easy-peasy to port some simple
> gfx-functions i got and put them into a small library..... is there any
> interest for that ? (i dont really need that myself but got the routines
> laying around anyway))
I've thought about a graphics library for some time, but I would prefer one
with a consistent interface across all supported platforms (at least the one
that support graphics). The C64 and the C128 could be handled by the same
code, the Plus4/C16/C116 has an almost identical memory layout in hires mode,
so these machines should be able to share quite some code with the C64
implementation. With some effort, it should also be possible to design these
routines so that they can be used by the P500 (which does also have the VIC
but uses a strange, CPU supported banking scheme) without too much changes. As
usual, I don't have enough knowledge about the Atari and the Apple to say what
is possible here.
If you think that the interface of your code is worth looking at, I would be
glad if you could send me a copy via email.
Regards
Uz
--
Ullrich von Bassewitz uz_at_musoftware.de
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This archive was generated by hypermail 2.1.3 : 2001-12-14 22:05:41 CET