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Added GPL header, tweaked other comments

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unknown 2015-03-24 12:04:32 +09:00
parent c2b62d26d3
commit b386c444c3
1 changed files with 38 additions and 11 deletions
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49
source/DAC.cpp
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@ -1,10 +1,34 @@
/*
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.
AppleWin : An Apple //e emulator for Windows
Riccardo Macri Mar 2015
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
*/
/*
DAC.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"
@ -28,7 +52,7 @@ static BYTE __stdcall IOWrite_DAC(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULON
byte mb_res;
if (soundtype == SOUND_WAVE)
if (soundtype == SOUND_WAVE)
{
// use existing speaker code to bring timing up to date
mb_res = SpkrToggle(pc, addr, bWrite, d, nCyclesLeft);
@ -40,16 +64,19 @@ static BYTE __stdcall IOWrite_DAC(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULON
// 0x00 0 0x80 -128
// replace regular speaker output with 8 bit DAC value
// regular speaker data still audible but muted until speaker
// goes idle
// 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);
else
mb_res = MemReadFloatingBus(nCyclesLeft);
return mb_res;
return mb_res;
}
void ConfigureDAC(LPBYTE pCxRomPeripheral, UINT uSlot)