Aded support for an 8 bit DAC in slot 5 if no Z80 card there. Demo disk

included.

source/DAC.cpp

@@ -0,0 +1,58 @@
+/*
+   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 "DAC.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 muted until speaker
+   // goes idle
+
+   g_nSpeakerData = (d ^ 0x80) << 8;
+   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);
+}

source/DAC.h

@@ -0,0 +1,2 @@
+// 8 bit DAC (eg: SAM)
+void ConfigureDAC(LPBYTE pCxRomPeripheral, UINT uSlot);