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