renamed DAC to SAM

2026-04-20 15:17:50 +00:00 · 2015-03-30 17:25:30 +09:00
parent b386c444c3
commit fa43e909ed
5 changed files with 10 additions and 10 deletions
@@ -0,0 +1,85 @@
+/*
+  AppleWin : An Apple //e emulator for Windows
+
+  Copyright (C) 1994-1996, Michael O'Brien
+  Copyright (C) 1999-2001, Oliver Schmidt
+  Copyright (C) 2002-2005, Tom Charlesworth
+  Copyright (C) 2006-2007, Tom Charlesworth, Michael Pohoreski
+
+  AppleWin is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  AppleWin is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with AppleWin; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+/*
+  SAM.CPP
+
+  Emulate an 8 bit DAC (eg: SAM card) which writes unsigned byte
+  data written to its IO area to the audio buffer (as used by the speaker).
+  This merges the data with the speaker stream, reducing the volume
+  of the Apple speaker when active.
+
+  Riccardo Macri  Mar 2015
+*/
+#include "StdAfx.h"
+
+#include "AppleWin.h"
+#include "Memory.h"
+#include "SAM.h"
+#include "Speaker.h"
+
+//
+// Write 8 bit data to speaker. Emulates a "SAM" speech card DAC
+//
+
+
+static BYTE __stdcall IOWrite_DAC(WORD pc,  WORD addr, BYTE bWrite, BYTE d, ULONG nCyclesLeft)
+{
+ // Emulate audio from an 8 bit DAC
+ // only if using wave data
+ // uses the existing speaker for the timing but then
+ // substitutes the analog data which gets subsequently
+ // sent to audio out
+
+ byte mb_res;
+
+ if (soundtype == SOUND_WAVE)
+  {
+   // use existing speaker code to bring timing up to date
+   mb_res = SpkrToggle(pc, addr, bWrite, d, nCyclesLeft);
+
+   // 8 bit card      WAV driver (scaled by 256)
+   //  0xFF 255       0x7f  127
+   //  0x80 128       0x00    0
+   //  0x7f 127       0xFF   -1
+   //  0x00  0        0x80 -128
+   
+   // replace regular speaker output with 8 bit DAC value
+   // regular speaker data still audible but quieter until speaker
+   // goes idle (so both work simultaneously)
+
+   g_nSpeakerData = (d ^ 0x80) << 8;
+
+   // make speaker quieter so eg: a metronome click through the
+   // Apple speaker is softer vs. the analogue SAM output
+   g_quieterSpeaker = 1;
+  }
+ else
+  mb_res = MemReadFloatingBus(nCyclesLeft);
+
+ return mb_res;
+}
+
+void ConfigureDAC(LPBYTE pCxRomPeripheral, UINT uSlot)
+{	
+ RegisterIoHandler(uSlot,IO_Null,IOWrite_DAC,IO_Null,IO_Null, NULL, NULL);
+}