Retro/pcem
Watch
1
0
Fork
You've already forked pcem
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add v0.7 source

Browse source
This commit is contained in:
TomW 2013-04-21 14:54:35 +01:00
commit 3c253c2cf8
188 changed files with 52566 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

74
src/vid_icd2061.c Normal file
View file

@ -0,0 +1,74 @@
/*PCem v0.7 by Tom Walker
ICD2061 clock generator emulation
Used by ET4000w32/p (Diamond Stealth 32)*/
#include "ibm.h"
#include "vid_icd2061.h"
static int icd2061_state;
static int icd2061_status = 0;
static int icd2061_pos = 0;
static int icd2061_unlock = 0;
static uint32_t icd2061_data;
static double icd2061_freq[4];
static uint32_t icd2061_ctrl;
void icd2061_write(int val)
{
int q, p, m, i, a;
if ((val & 1) && !(icd2061_state & 1))
{
pclog("ICD2061 write %02X %i %08X %i\n", val, icd2061_unlock, icd2061_data, icd2061_pos);
if (!icd2061_status)
{
if (val & 2) icd2061_unlock++;
else
{
if (icd2061_unlock >= 5)
{
icd2061_status = 1;
icd2061_pos = 0;
}
else
icd2061_unlock = 0;
}
}
else if (val & 1)
{
icd2061_data = (icd2061_data >> 1) | (((val & 2) ? 1 : 0) << 24);
icd2061_pos++;
if (icd2061_pos == 26)
{
pclog("ICD2061 data - %08X\n", icd2061_data);
a = (icd2061_data >> 21) & 0x7;
if (!(a & 4))
{
q = (icd2061_data & 0x7f) - 2;
m = 1 << ((icd2061_data >> 7) & 0x7);
p = ((icd2061_data >> 10) & 0x7f) - 3;
i = (icd2061_data >> 17) & 0xf;
pclog("p %i q %i m %i\n", p, q, m);
if (icd2061_ctrl & (1 << a))
p <<= 1;
icd2061_freq[a] = ((double)p / (double)q) * 2.0 * 14318184.0 / (double)m;
pclog("ICD2061 freq %i = %f\n", a, icd2061_freq[a]);
}
else if (a == 6)
{
icd2061_ctrl = val;
pclog("ICD2061 ctrl = %08X\n", val);
}
icd2061_unlock = icd2061_data = 0;
icd2061_status = 0;
}
}
}
icd2061_state = val;
}
double icd2061_getfreq(int i)
{
pclog("Return freq %f\n", icd2061_freq[i]);
return icd2061_freq[i];
}