static void
SDL_SetTimerSpeed(void)
{
word rate;
//void interrupt (*isr)(void); // PORT interrupts not available
if ((DigiMode == sds_PC) && DigiPlaying)
{
rate = TickBase * 100;
//isr = SDL_t0ExtremeAsmService; // PORT
}
else if
(
(MusicMode == smm_AdLib)
|| ((DigiMode == sds_SoundSource) && DigiPlaying)
)
{
rate = TickBase * 10;
//isr = SDL_t0FastAsmService; // PORT
}
else
{
rate = TickBase * 2;
//isr = SDL_t0SlowAsmService; // PORT
}
if (rate != TimerRate)
{
//setvect(8,isr); // PORT
SDL_SetIntsPerSec(rate);
TimerRate = rate;
}
}
///////////////////////////////////////////////////////////////////////////
//
// SDL_InitDelay() - Sets up TimerDelay's for SDL_Delay()
//
///////////////////////////////////////////////////////////////////////////
static void
SDL_InitDelay(void)
{
id0_int_t i;
id0_word_t timer,speed;
setvect(8,SDL_TimingService); // Set to my timer 0 ISR
SDL_SetIntsPerSec(1000); // Time 1ms
for (i = 0,timer = 0;i < 10;i++) // Do timing test 10 times
{
asm xor dx,dx // Zero DX
asm mov cx,0xffff // Put starting value in CX
asm mov [TimerDone],cx // TimerDone = false - 1
startloop:
asm or [TimerDone],0
asm jnz startloop // Make sure we're at the start
loop:
asm test [TimerDone],1 // See if TimerDone flag got hit
asm jnz done // Yep - drop out of the loop
asm loop loop
done:
if (0xffff - TimerVal > timer)
timer = 0xffff - TimerVal;
}
timer += timer / 2; // Use some slop
TimerDelay10 = timer / (1000 / 10);
TimerDelay25 = timer / (1000 / 25);
TimerDelay100 = timer / (1000 / 100);
SDL_SetTimer0(0); // Reset timer 0
setvect(8,t0OldService); // Set back to old ISR
}
