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/* |
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* SID.h - 6581 emulation |
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* |
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* Frodo (C) 1994-1997,2002-2005 Christian Bauer |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#ifndef _SID_H |
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#define _SID_H |
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|
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#include <stdlib.h> |
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|
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|
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// Define this if you want an emulation of an 8580 |
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// (affects combined waveforms) |
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#undef EMUL_MOS8580 |
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|
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|
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class Prefs; |
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class C64; |
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class SIDRenderer; |
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struct MOS6581State; |
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|
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// Class for administrative functions |
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class MOS6581 { |
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public: |
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MOS6581(C64 *c64); |
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~MOS6581(); |
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|
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void Reset(void); |
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uint8 ReadRegister(uint16 adr); |
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void WriteRegister(uint16 adr, uint8 byte); |
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void NewPrefs(Prefs *prefs); |
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void PauseSound(void); |
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void ResumeSound(void); |
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void GetState(MOS6581State *ss); |
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void SetState(MOS6581State *ss); |
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void EmulateLine(void); |
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|
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private: |
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void open_close_renderer(int old_type, int new_type); |
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|
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C64 *the_c64; // Pointer to C64 object |
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SIDRenderer *the_renderer; // Pointer to current renderer |
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uint8 regs[32]; // Copies of the 25 write-only SID registers |
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uint8 last_sid_byte; // Last value written to SID |
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}; |
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|
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|
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// Renderers do the actual audio data processing |
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class SIDRenderer { |
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public: |
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virtual ~SIDRenderer() {} |
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virtual void Reset(void)=0; |
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virtual void EmulateLine(void)=0; |
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virtual void WriteRegister(uint16 adr, uint8 byte)=0; |
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virtual void NewPrefs(Prefs *prefs)=0; |
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virtual void Pause(void)=0; |
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virtual void Resume(void)=0; |
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}; |
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|
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|
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// SID state |
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struct MOS6581State { |
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uint8 freq_lo_1; |
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uint8 freq_hi_1; |
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uint8 pw_lo_1; |
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uint8 pw_hi_1; |
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uint8 ctrl_1; |
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uint8 AD_1; |
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uint8 SR_1; |
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|
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uint8 freq_lo_2; |
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uint8 freq_hi_2; |
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uint8 pw_lo_2; |
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uint8 pw_hi_2; |
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uint8 ctrl_2; |
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uint8 AD_2; |
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uint8 SR_2; |
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|
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uint8 freq_lo_3; |
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uint8 freq_hi_3; |
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uint8 pw_lo_3; |
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uint8 pw_hi_3; |
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uint8 ctrl_3; |
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uint8 AD_3; |
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uint8 SR_3; |
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|
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uint8 fc_lo; |
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uint8 fc_hi; |
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uint8 res_filt; |
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uint8 mode_vol; |
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|
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uint8 pot_x; |
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uint8 pot_y; |
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uint8 osc_3; |
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uint8 env_3; |
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}; |
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|
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|
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/* |
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* Fill buffer (for Unix sound routines), sample volume (for sampled voice) |
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*/ |
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|
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inline void MOS6581::EmulateLine(void) |
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{ |
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if (the_renderer != NULL) |
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the_renderer->EmulateLine(); |
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} |
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|
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|
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/* |
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* Read from register |
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*/ |
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|
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inline uint8 MOS6581::ReadRegister(uint16 adr) |
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{ |
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// A/D converters |
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if (adr == 0x19 || adr == 0x1a) { |
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last_sid_byte = 0; |
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return 0xff; |
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} |
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|
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// Voice 3 oscillator/EG readout |
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if (adr == 0x1b || adr == 0x1c) { |
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last_sid_byte = 0; |
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return rand(); |
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} |
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|
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// Write-only register: Return last value written to SID |
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return last_sid_byte; |
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} |
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|
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|
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/* |
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* Write to register |
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*/ |
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|
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inline void MOS6581::WriteRegister(uint16 adr, uint8 byte) |
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{ |
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// Keep a local copy of the register values |
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last_sid_byte = regs[adr] = byte; |
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|
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if (the_renderer != NULL) |
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the_renderer->WriteRegister(adr, byte); |
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} |
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|
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#endif |
