mirror of
https://github.com/chocolate-doom/research.git
synced 2024-11-22 20:31:30 +00:00
82 lines
1.2 KiB
C
82 lines
1.2 KiB
C
|
|
// plays a tone via the OPL chip
|
|
// this will not work if you don't have an OPL chip.
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <sys/io.h>
|
|
|
|
#define PORT 0x388
|
|
|
|
void write_reg(int reg, int val)
|
|
{
|
|
int i;
|
|
|
|
outb(reg, PORT);
|
|
|
|
for (i=0; i<6; ++i) {
|
|
inb(PORT);
|
|
}
|
|
|
|
outb(val, PORT + 1);
|
|
|
|
for (i=0; i<35; ++i) {
|
|
inb(PORT);
|
|
}
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
char buf[64];
|
|
|
|
if (ioperm(PORT, 4, 1) != 0)
|
|
{
|
|
printf("Failed to get permissions\n");
|
|
exit(-1);
|
|
}
|
|
|
|
printf("got permissions\n");
|
|
|
|
write_reg(4, 0x60);
|
|
write_reg(4, 0x80);
|
|
int val1 = inb(PORT) & 0xe0;
|
|
write_reg(2, 0xff);
|
|
write_reg(4, 0x21);
|
|
sleep(1);
|
|
int val2 = inb(PORT) & 0xe0;
|
|
write_reg(4, 0x60);
|
|
write_reg(4, 0x80);
|
|
|
|
if (val1 == 0 && val2 == 0xc0)
|
|
{
|
|
printf("OPL detected\n");
|
|
}
|
|
else
|
|
{
|
|
printf("not detected - %i, %i\n", val1, val2);
|
|
exit(-1);
|
|
}
|
|
|
|
// program a sound
|
|
|
|
write_reg(0x20, 0x01);
|
|
write_reg(0x40, 0x10);
|
|
write_reg(0x60, 0xf0);
|
|
write_reg(0x80, 0x77);
|
|
write_reg(0xa0, 0x98);
|
|
write_reg(0x23, 0x01);
|
|
write_reg(0x43, 0x00);
|
|
write_reg(0x63, 0xf0);
|
|
write_reg(0x83, 0x77);
|
|
write_reg(0xb0, 0x31);
|
|
|
|
gets(buf);
|
|
|
|
// turn the sound off
|
|
|
|
write_reg(0xb0, 0x11);
|
|
|
|
return 0;
|
|
}
|
|
|