In the function PDC_query_adapter_type() in dos/pdcgetsc.c, the DOS port
of PDCurses attempts to compensate for the CGA snow effect, by setting
writes to BIOS mode if CGA is detected:
if ((retval == _NONE)
#ifndef CGA_DIRECT
|| (retval == _CGA)
#endif
)
{
SP->direct_video = FALSE;
}
However, this is thwarted, because PDC_query_adapter_type() is called only
from PDC_scr_open() in dos/pdcscrn.c:
internal->adapter = PDC_query_adapter_type();
where it's shortly followed by this code:
/*
* If the environment variable PDCURSES_BIOS is set, the DOS int10()
* BIOS calls are used in place of direct video memory access.
*/
internal->direct_video = TRUE;
if (getenv("PDCURSES_BIOS") != NULL)
internal->direct_video = FALSE;
which resets it. I suggest moving the "internal->direct_video = TRUE;"
statement above the call to PDC_query_adapter_type(); i.e.:
internal->direct_video = TRUE;
...
internal->adapter = PDC_query_adapter_type();
...
if (getenv("PDCURSES_BIOS") != NULL)
internal->direct_video = FALSE;
Alternately, the "internal->direct_video = TRUE;" statement could be
removed, and:
else
SP->direct_video = TRUE;
added to the lines from PDC_query_adapter_type(), above.
BTW, for my own use, I've made a no-snow direct video mode for CGA; but to
achieve it, I had to compile pdcdisp.c to assembly language and then hack
the asm. So I'm assuming that code is unsuitable for general PDCurses use.
--
William McBrine | http://www.clark.net/~wmcbrine/
[EMAIL PROTECTED] | Think.
