void ramtek_videoram_w (int offset,int data)
{
data = data & ~mask;
if (videoram[offset] != data)
{
int i,x,y;
videoram[offset] = data;
y = offset / 32;
x = 8 * (offset % 32);
for (i = 0; i < 8; i++)
{
plot_pixel2(Machine->scrbitmap, tmpbitmap, x, y, Machine->pens[(data & 0x80) ? WHITE : BLACK]);
x++;
data <<= 1;
}
}
}
/***************************************************************************
Draw the game screen in the given osd_bitmap.
Do NOT call osd_update_display() from this function, it will be called by
the main emulation engine.
***************************************************************************/
void spiders_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int loop,data0,data1,data2,col;
size_t crtc6845_mem_size;
int video_addr,increment;
unsigned char *RAM = memory_region(REGION_CPU1);
crtc6845_mem_size=crtc6845_horiz_disp*crtc6845_vert_disp*8;
if(spiders_video_flip)
{
video_addr=crtc6845_start_addr+(crtc6845_mem_size-1);
if((video_addr&0xff)==0x80) video_addr-=0x80; /* Fudge factor!!! */
increment=-1;
}
else
{
video_addr=crtc6845_start_addr;
increment=1;
}
video_addr&=0xfbff; /* Fudge factor: sometimes this bit gets set and */
/* I've no idea how it maps to the hardware but */
/* everything works OK if we do this */
if(crtc6845_page_flip) video_addr+=0x2000;
for(loop=0;loop<crtc6845_mem_size;loop++)
{
int i,x,y,combo;
if(spiders_video_flip)
{
data0=bitflip[RAM[0x0000+video_addr]];
data1=bitflip[RAM[0x4000+video_addr]];
data2=bitflip[RAM[0x8000+video_addr]];
}
else
{
data0=RAM[0x0000+video_addr];
data1=RAM[0x4000+video_addr];
data2=RAM[0x8000+video_addr];
}
combo=data0|(data1<<8)|(data2<<16);
if(screenbuffer[video_addr&SCREENBUFFER_MASK]!=combo)
{
y=loop/0x20;
for(i=0;i<8;i++)
{
x=((loop%0x20)<<3)+i;
col=((data2&0x01)<<2)+((data1&0x01)<<1)+(data0&0x01);
plot_pixel2(bitmap, tmpbitmap, x, y, Machine->pens[col]);
data0 >>= 1;
data1 >>= 1;
data2 >>= 1;
}
screenbuffer[video_addr&SCREENBUFFER_MASK]=combo;
}
video_addr+=increment;
video_addr&=0x3fff;
}
