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1.1 root 1: /*
2: Hatari
3:
4: Programmable Sound Generator (YM-2149) - PSG
1.1.1.3 ! root 5:
! 6: ChangeLog:
! 7:
! 8: 9 Aug 2003 Matthias Arndt <[email protected]>
! 9: - added hook for printer dispatcher to PSG Port B (Reg 15)
! 10: - added flag to decide if last write did go to IOB
! 11:
! 12: 10 Aug 2003
! 13: - corrected bug in printer dispatcher: STROBE is Bit5 counted from 0 (32 instead of 16)
1.1 root 14: */
15:
16: #include "main.h"
1.1.1.3 ! root 17: #include "configuration.h"
1.1 root 18: #include "memAlloc.h"
19: #include "memorySnapShot.h"
20: #include "sound.h"
1.1.1.3 ! root 21: #include "psg.h"
! 22:
! 23: /* printer.h because Printer I/O goes through PSG Register 15 */
! 24: #include "printer.h"
1.1 root 25:
26: unsigned char PSGRegisterSelect = 0; /* 0xff8800 (read/write) */
27: unsigned char PSGRegisters[16] = { 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0 }; /* Register in PSG, see PSG_REG_xxxx */
28:
1.1.1.3 ! root 29: /* boolean flag: did the last write to the PSG go to IOB? */
! 30: BOOL bPSG_LastWriteToIOB;
1.1 root 31:
32: /*-----------------------------------------------------------------------*/
33: /*
34: Reset variables used in PSG
35: */
36: void PSG_Reset(void)
37: {
38: PSGRegisterSelect = 0;
39: Memory_Clear(PSGRegisters,sizeof(unsigned char)*16);
1.1.1.3 ! root 40: bPSG_LastWriteToIOB=FALSE;
1.1 root 41: }
42:
1.1.1.2 root 43:
44: /*-----------------------------------------------------------------------*/
1.1 root 45: /*
46: Save/Restore snapshot of local variables('MemorySnapShot_Store' handles type)
47: */
48: void PSG_MemorySnapShot_Capture(BOOL bSave)
49: {
1.1.1.2 root 50: /* Save/Restore details */
1.1 root 51: MemorySnapShot_Store(&PSGRegisterSelect,sizeof(PSGRegisterSelect));
52: MemorySnapShot_Store(PSGRegisters,sizeof(PSGRegisters));
53: }
54:
1.1.1.2 root 55:
56: /*-----------------------------------------------------------------------*/
1.1 root 57: /*
58: Write byte to 0xff88000, this is used as a selector for when we read/write to address 0xff8802
59: */
60: void PSG_WriteSelectRegister(unsigned short v)
61: {
62: PSGRegisterSelect = v & 0x0f; /* Store register to select (value in bits 0-3) */
63: }
64:
1.1.1.2 root 65:
66: /*-----------------------------------------------------------------------*/
1.1 root 67: /*
68: Read byte from 0xff8800, returns to PSG data
69: */
70: unsigned short PSG_ReadSelectRegister(void)
71: {
1.1.1.2 root 72: /* Read data last selected by register */
1.1 root 73: return PSGRegisters[PSGRegisterSelect]; /* Return value from PSGRegisters[] */
74: }
75:
1.1.1.2 root 76:
77: /*-----------------------------------------------------------------------*/
1.1 root 78: /*
79: Write byte to 0xff8802, stores according to PSG select register(write 0xff8800)
80: */
81: void PSG_WriteDataRegister(unsigned short bl)
82: {
83: Sound_Update(); /* Create samples up until this point with current values */
84: PSGRegisters[PSGRegisterSelect]=bl; /* Write value to PSGRegisters[] */
85: if( PSGRegisterSelect==13 ) /* Whenever 'write' to register 13, cause envelope to reset */
86: {
87: bEnvelopeFreqFlag = TRUE;
88: bWriteEnvelopeFreq = TRUE;
89: }
1.1.1.3 ! root 90:
! 91: /* Matthias Arndt <[email protected]> 9 Aug 2003
! 92: * FIXME: This is only a prelimary dirty hack!
! 93: * Port B (Printer port) - writing here needs to be dispatched to the printer
! 94: * STROBE (Port A bit5) does a short LOW and back to HIGH when the char is valid
! 95: * To print you need to write the character byte to IOB and you need to toggle STROBE
! 96: * (like EmuTOS does)....therefor we print when STROBE gets low and last write access to
! 97: * the PSG was to IOB
! 98: */
! 99: if(ConfigureParams.Printer.bEnablePrinting) /* Printer dispatching only when printing is activated */
! 100: {
! 101: if( PSGRegisterSelect==PSG_REG_IO_PORTA )
! 102: {
! 103: /* is STROBE LOW? */
! 104: if((PSGRegisters[PSG_REG_IO_PORTA]&32)==0)
! 105: /* did the last write go to IOB? then we want to print something... */
! 106: if(bPSG_LastWriteToIOB==TRUE)
! 107: Printer_TransferByteTo(((unsigned char) PSGRegisters[PSG_REG_IO_PORTB] & 0xff));
! 108:
! 109: bPSG_LastWriteToIOB=FALSE;
! 110: }
! 111: else
! 112: if( PSGRegisterSelect==PSG_REG_IO_PORTB )
! 113: {
! 114: bPSG_LastWriteToIOB=TRUE;
! 115: }
! 116: else
! 117: bPSG_LastWriteToIOB=FALSE;
! 118: }
! 119:
1.1 root 120: /* Check registers 8,9 and 10 which are 'amplitude' for each channel and store if wrote to(to check for sample playback) */
121: if( PSGRegisterSelect==8 )
122: bWriteChannelAAmp=TRUE;
123: else if( PSGRegisterSelect==9 )
124: bWriteChannelBAmp=TRUE;
125: else if( PSGRegisterSelect==10 )
126: bWriteChannelCAmp=TRUE;
127: }
128:
1.1.1.2 root 129:
130: /*-----------------------------------------------------------------------*/
1.1 root 131: /*
132: Read byte from 0xff8802, returns 0xff
133: */
134: unsigned short PSG_ReadDataRegister(void)
135: {
136: return 0xff;
137: }
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