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/* |
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* SID_linux.h - 6581 emulation, Linux specific stuff |
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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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#include <unistd.h> |
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#include <fcntl.h> |
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#include <sys/ioctl.h> |
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#include <linux/soundcard.h> |
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|
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// Catweasel ioctls (included here for convenience) |
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#include <linux/ioctl.h> |
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#define CWSID_IOCTL_TYPE ('S') |
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#define CWSID_IOCTL_RESET _IO(CWSID_IOCTL_TYPE, 0) |
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#define CWSID_IOCTL_CARDTYPE _IOR(CWSID_IOCTL_TYPE, 4, int) |
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#define CWSID_IOCTL_PAL _IO(CWSID_IOCTL_TYPE, 0x11) |
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#define CWSID_IOCTL_NTSC _IO(CWSID_IOCTL_TYPE, 0x12) |
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#define CWSID_IOCTL_DOUBLEBUFFER _IOW(CWSID_IOCTL_TYPE, 0x21, int) |
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#define CWSID_IOCTL_DELAY _IOW(CWSID_IOCTL_TYPE, 0x22, int) |
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#define CWSID_MAGIC 0x100 |
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#define HAVE_CWSID 1 |
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|
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#include "VIC.h" |
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|
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|
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/* |
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* Initialization |
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*/ |
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|
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void DigitalRenderer::init_sound(void) |
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{ |
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int arg; |
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unsigned long format; |
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|
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ready = false; |
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devfd = open("/dev/dsp", O_WRONLY); |
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if (devfd < 0) |
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return; |
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|
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ioctl(devfd, SNDCTL_DSP_GETFMTS, &format); |
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if (!(format & AFMT_S16_LE)) |
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return; |
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format = AFMT_S16_LE; |
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ioctl(devfd, SNDCTL_DSP_SETFMT, &format); |
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|
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// Buffer size: 2^9 == 512 bytes. Note that too large buffers will not work |
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// very well: The speed of the C64 is slowed down to an average speed of |
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// 100% by the blocking write() call in EmulateLine(). If you use a buffer |
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// of, say 4096 bytes, that will happen only about every 4 frames, which |
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// means that the emulation runs much faster in some frames, and much |
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// slower in others. |
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// On really fast machines, it might make sense to use an even smaller |
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// buffer size. |
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arg = 0x00100009; |
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ioctl(devfd, SNDCTL_DSP_SETFRAGMENT, &arg); |
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arg = 0; |
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ioctl(devfd, SNDCTL_DSP_STEREO, &arg); |
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arg = 44100; |
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ioctl(devfd, SNDCTL_DSP_SPEED, &arg); |
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ioctl(devfd, SOUND_PCM_READ_RATE, &arg); |
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if (arg < 43000 || arg > 45000) |
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return; |
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|
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ioctl(devfd, SNDCTL_DSP_GETBLKSIZE, &sndbufsize); |
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sound_buffer = new int16[sndbufsize]; |
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ready = true; |
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} |
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|
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|
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/* |
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* Destructor |
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*/ |
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|
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DigitalRenderer::~DigitalRenderer() |
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{ |
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if (devfd >= 0) |
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close(devfd); |
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} |
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|
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|
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/* |
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* Pause sound output |
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*/ |
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|
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void DigitalRenderer::Pause(void) |
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{ |
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} |
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|
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|
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/* |
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* Resume sound output |
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*/ |
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|
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void DigitalRenderer::Resume(void) |
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{ |
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} |
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|
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|
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/* |
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* Fill buffer, sample volume (for sampled voice) |
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*/ |
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|
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void DigitalRenderer::EmulateLine(void) |
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{ |
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static int divisor = 0; |
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static int to_output = 0; |
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static int buffer_pos = 0; |
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|
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if (!ready) |
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return; |
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|
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sample_buf[sample_in_ptr] = volume; |
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sample_in_ptr = (sample_in_ptr + 1) % SAMPLE_BUF_SIZE; |
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|
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// Now see how many samples have to be added for this line |
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divisor += SAMPLE_FREQ; |
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while (divisor >= 0) |
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divisor -= TOTAL_RASTERS*SCREEN_FREQ, to_output++; |
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|
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// Calculate the sound data only when we have enough to fill |
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// the buffer entirely |
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if ((buffer_pos + to_output) >= sndbufsize) { |
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int datalen = sndbufsize - buffer_pos; |
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to_output -= datalen; |
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calc_buffer(sound_buffer + buffer_pos, datalen*2); |
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write(devfd, sound_buffer, sndbufsize*2); |
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buffer_pos = 0; |
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} |
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} |
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|
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|
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/* |
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* Renderer for Catweasel card |
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*/ |
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|
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// Renderer class |
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class CatweaselRenderer : public SIDRenderer { |
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public: |
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CatweaselRenderer(); |
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virtual ~CatweaselRenderer(); |
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|
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virtual void Reset(void); |
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virtual void EmulateLine(void) {} |
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virtual void WriteRegister(uint16 adr, uint8 byte); |
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virtual void NewPrefs(Prefs *prefs) {} |
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virtual void Pause(void) {} |
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virtual void Resume(void) {} |
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|
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private: |
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int cwsid_fh; // Catweasel device file handle |
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}; |
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|
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// Constructor: Open Catweasel device and reset SID |
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CatweaselRenderer::CatweaselRenderer() |
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{ |
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cwsid_fh = open("/dev/sid", O_WRONLY); |
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if (cwsid_fh >= 0) { |
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int i; |
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if (ioctl(cwsid_fh, CWSID_IOCTL_CARDTYPE, &i) < 0 || i != CWSID_MAGIC) { |
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close(cwsid_fh); |
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cwsid_fh = -1; |
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} else { |
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ioctl(cwsid_fh, CWSID_IOCTL_RESET); |
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ioctl(cwsid_fh, CWSID_IOCTL_DOUBLEBUFFER, 0); |
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} |
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} |
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|
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Reset(); |
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} |
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|
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// Destructor: Reset SID and close Catweasel device |
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CatweaselRenderer::~CatweaselRenderer() |
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{ |
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Reset(); |
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|
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if (cwsid_fh >= 0) { |
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close(cwsid_fh); |
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cwsid_fh = -1; |
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} |
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} |
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|
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// Reset SID |
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void CatweaselRenderer::Reset(void) |
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{ |
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if (cwsid_fh >= 0) { |
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uint8 zero = 0; |
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ioctl(cwsid_fh, CWSID_IOCTL_RESET); |
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lseek(cwsid_fh, 24, SEEK_SET); |
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write(cwsid_fh, &zero, 1); |
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} |
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} |
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|
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// Write to register |
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void CatweaselRenderer::WriteRegister(uint16 adr, uint8 byte) |
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{ |
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if (cwsid_fh >= 0 && adr < 0x1a) { |
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lseek(cwsid_fh, adr, SEEK_SET); |
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write(cwsid_fh, &byte, 1); |
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lseek(cwsid_fh, adr, SEEK_SET); |
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write(cwsid_fh, &byte, 1); |
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} |
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} |