void vic_store(WORD addr, BYTE value)
{
addr &= 0xf;
vic.regs[addr] = value;
VIC_DEBUG_REGISTER (("VIC: write $90%02X, value = $%02X.", addr, value));
switch (addr) {
#if 0
/* handled in vic_cycle.c */
case 0: /* $9000 Screen X Location. */
/*
VIC checks in cycle n for peek($9000)=n
and in this case opens the horizontal flipflop
*/
case 1: /* $9001 Screen Y Location. */
/*
VIC checks from cycle 1 of line r*2 to cycle 0 of line r*2+2
if peek($9001)=r is true and in this case it opens the vertical
flipflop
*/
case 2: /* $9002 Columns Displayed. */
case 5: /* $9005 Video and char matrix base
address. */
/* read-only registers */
case 4: /* $9004 Raster line count -- read only. */
case 6: /* $9006. */
case 7: /* $9007 Light Pen X,Y. */
case 8: /* $9008. */
case 9: /* $9009 Paddle X,Y. */
#endif
default:
return;
case 3: /* $9003 Rows Displayed, Character size . */
{
int new_char_height = (value & 0x1) ? 16 : 8;
vic.row_increase_line = new_char_height;
vic.char_height = new_char_height;
}
return;
case 10: /* $900A Bass Enable and Frequency. */
case 11: /* $900B Alto Enable and Frequency. */
case 12: /* $900C Soprano Enable and Frequency. */
case 13: /* $900D Noise Enable and Frequency. */
vic_sound_store(addr, value);
return;
case 14: /* $900E Auxiliary Colour, Master Volume. */
/*
changes of auxiliary color in cycle n is visible at pixel 4*(n-7)+1
*/
{
static int old_aux_color = -1;
int new_aux_color = value>>4;
if (new_aux_color != old_aux_color) {
/* integer part */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR_INT(vic.raster_cycle+1),
&vic.auxiliary_color,
new_aux_color);
/* fractional part (half chars) */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR_INT(vic.raster_cycle+1),
&vic.half_char_flag,
VIC_RASTER_CHAR_FRAC(vic.raster_cycle+1));
/* old_mc_auxilary_color is used by vic-draw.c to handle the
one hires vic pixel lateness of change */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR(vic.raster_cycle+2),
&vic.old_auxiliary_color,
new_aux_color);
old_aux_color = new_aux_color;
}
}
vic_sound_store(addr, value);
return;
case 15: /* $900F Screen and Border Colors,
Reverse Video. */
/*
changes of border/background in cycle n are visible at pixel
4*(n-7)+1, changes of reverse mode at pixel 4*(n-7)+3.
*/
{
static int old_background_color = -1;
static int old_border_color = -1;
static int old_reverse = -1;
int new_background_color, new_border_color, new_reverse;
new_background_color = value>>4;
new_border_color = value & 0x7;
new_reverse = ((value & 0x8) ? 0 : 1);
if (new_background_color != old_background_color) {
raster_changes_background_add_int(&vic.raster,
VIC_RASTER_X(vic.raster_cycle+1) + VIC_PIXEL_WIDTH,
(int*)&vic.raster.background_color,
new_background_color);
old_background_color = new_background_color;
}
if (new_border_color != old_border_color) {
raster_changes_border_add_int(&vic.raster,
VIC_RASTER_X(vic.raster_cycle+1) + VIC_PIXEL_WIDTH,
(int*)&vic.raster.border_color,
new_border_color);
/* we also need the border color in multicolor mode,
so we duplicate it */
/* integer part */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR_INT(vic.raster_cycle+1),
&vic.mc_border_color,
new_border_color);
/* fractional part (half chars) */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR_INT(vic.raster_cycle+1),
&vic.half_char_flag,
VIC_RASTER_CHAR_FRAC(vic.raster_cycle+1));
}
if (new_reverse != old_reverse) {
/* integer part */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR_INT(vic.raster_cycle+1),
&vic.reverse,
new_reverse);
/* fractional part (half chars) */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR_INT(vic.raster_cycle+1),
&vic.half_char_flag,
VIC_RASTER_CHAR_FRAC(vic.raster_cycle+1));
}
if (new_border_color != old_border_color) {
/* old_mc_border_color is used by vic-draw.c to handle the
one hires vic pixel lateness of change */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR(vic.raster_cycle+2),
&vic.old_mc_border_color,
new_border_color);
old_border_color = new_border_color;
}
if (new_reverse != old_reverse) {
/* old_reverse is used by vic-draw.c to handle the
3 hires vic pixels lateness of change */
raster_changes_foreground_add_int(&vic.raster,
VIC_RASTER_CHAR(vic.raster_cycle+2),
&vic.old_reverse,
new_reverse);
old_reverse = new_reverse;
}
return;
}
}
}
/* Set the memory pointers according to the values stored in the VIC
registers. */
void vic_update_memory_ptrs(void)
{
static BYTE *old_chargen_ptr = NULL;
static BYTE *old_color_ptr = NULL;
static BYTE *old_screen_ptr = NULL;
WORD char_addr;
int tmp;
BYTE *new_chargen_ptr;
BYTE *new_color_ptr;
BYTE *new_screen_ptr;
tmp = vic.regs[0x5] & 0xf;
char_addr = (tmp & 0x8) ? 0x0000 : 0x8000;
char_addr += (tmp & 0x7) * 0x400;
if (char_addr >= 0x8000 && char_addr < 0x9000) {
new_chargen_ptr = vic20memrom_chargen_rom + 0x400 + (char_addr & 0xfff);
VIC_DEBUG_REGISTER(("Character memory at $%04X "
"(character ROM + $%04X).",
char_addr,
char_addr & 0xfff));
} else {
if (char_addr == 0x1c00)
new_chargen_ptr = vic20memrom_chargen_rom; /* handle wraparound */
else
new_chargen_ptr = mem_ram + char_addr;
VIC_DEBUG_REGISTER (("Character memory at $%04X.", char_addr));
}
new_color_ptr = mem_ram + 0x9400 + (vic.regs[0x2] & 0x80 ? 0x200 : 0x0);
new_screen_ptr = mem_ram + (((vic.regs[0x2] & 0x80) << 2)
| ((vic.regs[0x5] & 0x70) << 6));
VIC_DEBUG_REGISTER(("Color memory at $%04X.", vic.color_ptr - ram));
VIC_DEBUG_REGISTER(("Screen memory at $%04X.", vic.screen_ptr - ram));
if (new_chargen_ptr != old_chargen_ptr) {
raster_changes_foreground_add_ptr(&vic.raster,
VIC_RASTER_CHAR(VIC_RASTER_CYCLE(maincpu_clk)
+ 2),
(void*)&vic.chargen_ptr,
new_chargen_ptr);
old_chargen_ptr = new_chargen_ptr;
}
if (new_color_ptr != old_color_ptr) {
raster_changes_foreground_add_ptr(&vic.raster,
VIC_RASTER_CHAR(VIC_RASTER_CYCLE(maincpu_clk)
+ 3),
(void*)&vic.color_ptr,
new_color_ptr);
old_color_ptr = new_color_ptr;
}
if (new_screen_ptr != old_screen_ptr) {
raster_changes_foreground_add_ptr(&vic.raster,
VIC_RASTER_CHAR(VIC_RASTER_CYCLE(maincpu_clk)
+ 3),
(void*)&vic.screen_ptr,
new_screen_ptr);
old_screen_ptr = new_screen_ptr;
}
}