static int att20c490_probe(void)
{
unsigned char oldcomm, notcomm, oldpel, v;
int flag = 0;
_ramdac_dactocomm();
oldcomm = port_in(PEL_MSK);
_ramdac_dactopel();
oldpel = port_in(PEL_MSK);
notcomm = ~oldcomm;
port_out_r(PEL_MSK, notcomm);
_ramdac_dactocomm();
v = port_in(PEL_MSK);
if (v != notcomm) {
if ((_ramdac_setcomm(0xe0) & 0xe0) == 0xe0) {
if ((_ramdac_setcomm(0x60) & 0xe0) == 0) {
if ((_ramdac_setcomm(2) & 2) > 0)
flag = 1; /* 20c490 */
else
flag = 1; /* 20c493 */
} else {
_ramdac_setcomm(oldcomm);
if (port_in(PEL_MSK) == notcomm)
if (_ramdac_setcomm(0xFF) == 0xFF)
flag = 1; /* 20c491/20c492 */
}
}
}
_ramdac_dactocomm();
port_out_r(PEL_MSK, oldcomm);
_ramdac_dactopel();
port_out_r(PEL_MSK, oldpel);
return flag;
}
unsigned char _ramdac_setcomm(unsigned char data)
{
_ramdac_dactocomm();
port_out_r(PEL_MSK, data);
_ramdac_dactocomm();
return port_in(PEL_MSK);
}
static int ICW_probe(void)
{
unsigned char mi, di;
_ramdac_dactocomm();
port_in(PEL_MSK); /* Control register 0. */
mi = port_in(PEL_MSK); /* Manufacturer ID. */
di = port_in(PEL_MSK); /* Device ID. */
if (mi == 0x84) {
if (di == 0x98)
return 1;
fprintf(stderr,"svgalib: ICW_probe: Unknown IC Works DAC.\n");
}
return 0;
}
