/**
* Check if end-of-frame has been reached and raise interrupts if needed.
* Returns TRUE if DMA sound processing should be stopped now and FALSE
* if it continues.
*/
static inline int DmaSnd_CheckForEndOfFrame(int nFrameCounter)
{
if (nFrameCounter >= nFrameLen)
{
/* Raise end-of-frame interrupts (MFP-i7 and Time-A) */
MFP_InputOnChannel(MFP_TIMER_GPIP7_BIT, MFP_IERA, &MFP_IPRA);
if (MFP_TACR == 0x08) /* Is timer A in Event Count mode? */
MFP_TimerA_EventCount_Interrupt();
if (nDmaSoundControl & DMASNDCTRL_PLAYLOOP)
{
DmaSnd_StartNewFrame();
}
else
{
nDmaSoundControl &= ~DMASNDCTRL_PLAY;
return TRUE;
}
}
return FALSE;
}
/**
* Write byte to YM's register (0xff8802), store according to PSG select register (0xff8800)
*/
void PSG_Set_DataRegister(Uint8 val)
{
if (LOG_TRACE_LEVEL(TRACE_PSG_WRITE))
{
int FrameCycles, HblCounterVideo, LineCycles;
Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
LOG_TRACE_PRINT("ym write data reg=0x%x val=0x%x video_cyc=%d %d@%d pc=%x instr_cycle %d\n",
PSGRegisterSelect, val, FrameCycles, LineCycles,
HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
}
/* Is a valid PSG register currently selected ? */
if ( PSGRegisterSelect >= MAX_PSG_REGISTERS )
return; /* not valid, ignore write and do nothing */
/* Create samples up until this point with current values */
Sound_Update(false);
/* When a read is made from $ff8800 without changing PSGRegisterSelect, we should return */
/* the non masked value. */
PSGRegisterReadData = val; /* store non masked value for PSG_Get_DataRegister */
/* Copy value to PSGRegisters[] */
PSGRegisters[PSGRegisterSelect] = val;
/* Clear unused bits for some regs */
if ( ( PSGRegisterSelect == PSG_REG_CHANNEL_A_COARSE ) || ( PSGRegisterSelect == PSG_REG_CHANNEL_B_COARSE )
|| ( PSGRegisterSelect == PSG_REG_CHANNEL_C_COARSE ) || ( PSGRegisterSelect == PSG_REG_ENV_SHAPE ) )
PSGRegisters[PSGRegisterSelect] &= 0x0f; /* only keep bits 0 - 3 */
else if ( ( PSGRegisterSelect == PSG_REG_CHANNEL_A_AMP ) || ( PSGRegisterSelect == PSG_REG_CHANNEL_B_AMP )
|| ( PSGRegisterSelect == PSG_REG_CHANNEL_C_AMP ) || ( PSGRegisterSelect == PSG_REG_NOISE_GENERATOR ) )
PSGRegisters[PSGRegisterSelect] &= 0x1f; /* only keep bits 0 - 4 */
if ( PSGRegisterSelect < NUM_PSG_SOUND_REGISTERS )
{
/* Copy sound related registers 0..13 to the sound module's internal buffer */
Sound_WriteReg ( PSGRegisterSelect , PSGRegisters[PSGRegisterSelect] );
}
else if ( PSGRegisterSelect == PSG_REG_IO_PORTA )
{
/*
* FIXME: This is only a prelimary dirty hack!
* Port B (Printer port) - writing here needs to be dispatched to the printer
* STROBE (Port A bit5) does a short LOW and back to HIGH when the char is valid
* To print you need to write the character byte to IOB and you need to toggle STROBE
* (like EmuTOS does).
*/
/* Printer dispatching only when printing is activated */
if (ConfigureParams.Printer.bEnablePrinting)
{
/* Bit 5 - Centronics strobe? If STROBE is low and the LastStrobe was high,
then print/transfer to the emulated Centronics port.
*/
if (LastStrobe && ( (PSGRegisters[PSG_REG_IO_PORTA]&(1<<5)) == 0 ))
{
/* Seems like we want to print something... */
Printer_TransferByteTo(PSGRegisters[PSG_REG_IO_PORTB]);
/* Initiate a possible GPIP0 Printer BUSY interrupt */
MFP_InputOnChannel ( MFP_INT_GPIP0 , 0 );
/* Initiate a possible GPIP1 Falcon ACK interrupt */
if (ConfigureParams.System.nMachineType == MACHINE_FALCON)
MFP_InputOnChannel ( MFP_INT_GPIP1 , 0 );
}
}
LastStrobe = PSGRegisters[PSG_REG_IO_PORTA]&(1<<5);
/* Bit 0-2 : side and drive select */
if ( (PSGRegisters[PSG_REG_IO_PORTA]&(1<<1)) == 0 )
{
/* floppy drive A is ON */
Statusbar_SetFloppyLed(DRIVE_LED_A, LED_STATE_ON);
}
else
{
Statusbar_SetFloppyLed(DRIVE_LED_A, LED_STATE_OFF);
}
if ( (PSGRegisters[PSG_REG_IO_PORTA]&(1<<2)) == 0 )
{
/* floppy drive B is ON */
Statusbar_SetFloppyLed(DRIVE_LED_B, LED_STATE_ON);
}
else
{
Statusbar_SetFloppyLed(DRIVE_LED_B, LED_STATE_OFF);
}
/* Bit 3 - Centronics as input */
if(PSGRegisters[PSG_REG_IO_PORTA]&(1<<3))
{
/* FIXME: might be needed if we want to emulate sound sampling hardware */
}
/* handle Falcon specific bits in PORTA of the PSG */
if (ConfigureParams.System.nMachineType == MACHINE_FALCON)
{
/* Bit 4 - DSP reset? */
if(PSGRegisters[PSG_REG_IO_PORTA]&(1<<4))
{
Log_Printf(LOG_DEBUG, "Calling DSP_Reset?\n");
#if ENABLE_DSP_EMU
if (ConfigureParams.System.nDSPType == DSP_TYPE_EMU) {
DSP_Reset();
}
#endif
}
/* Bit 6 - Internal Speaker control */
if(PSGRegisters[PSG_REG_IO_PORTA]&(1<<6))
{
/*Log_Printf(LOG_DEBUG, "Falcon: Internal Speaker state\n");*/
/* FIXME: add code to handle? (if we want to emulate the speaker at all? */
}
/* Bit 7 - Reset IDE? */
if(PSGRegisters[PSG_REG_IO_PORTA]&(1<<7))
{
Log_Printf(LOG_DEBUG, "Falcon: Reset IDE subsystem\n");
/* FIXME: add code to handle IDE reset */
}
}
}
}
