claunia/86Box
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Initial submission of the PCem-Experimental source code.

Browse Source
This commit is contained in:
OBattler
2016-06-26 00:34:39 +02:00
parent 09d7c4384f
commit fd2a5bc9f5
610 changed files with 184352 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

55
src/vid_ics2595.c Normal file
View File

@@ -0,0 +1,55 @@
/*ICS2595 clock chip emulation
Used by ATI Mach64*/
#include "ibm.h"
#include "vid_ics2595.h"
enum
{
ICS2595_IDLE = 0,
ICS2595_WRITE,
ICS2595_READ
};
static int ics2595_div[4] = {8, 4, 2, 1};
void ics2595_write(ics2595_t *ics2595, int strobe, int dat)
{
// pclog("ics2595_write : %i %i\n", strobe, dat);
if (strobe)
{
if ((dat & 8) && !ics2595->oldfs3) /*Data clock*/
{
// pclog(" - new dat %i\n", dat & 4);
switch (ics2595->state)
{
case ICS2595_IDLE:
ics2595->state = (dat & 4) ? ICS2595_WRITE : ICS2595_IDLE;
ics2595->pos = 0;
break;
case ICS2595_WRITE:
ics2595->dat = (ics2595->dat >> 1);
if (dat & 4)
ics2595->dat |= (1 << 19);
ics2595->pos++;
if (ics2595->pos == 20)
{
int d, n, l;
// pclog("ICS2595_WRITE : dat %08X\n", ics2595->dat);
l = (ics2595->dat >> 2) & 0xf;
n = ((ics2595->dat >> 7) & 255) + 257;
d = ics2595_div[(ics2595->dat >> 16) & 3];
ics2595->clocks[l] = (14318181.8 * ((double)n / 46.0)) / (double)d;
// pclog("ICS2595 clock set - L %i N %i D %i freq = %f\n", l, n, d, (14318181.8 * ((double)n / 46.0)) / (double)d);
ics2595->state = ICS2595_IDLE;
}
break;
}
}
ics2595->oldfs2 = dat & 4;
ics2595->oldfs3 = dat & 8;
}
ics2595->output_clock = ics2595->clocks[dat];
}