1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* BRLTTY - A background process providing access to the console screen (when in
* text mode) for a blind person using a refreshable braille display.
*
* Copyright (C) 1995-2010 by The BRLTTY Developers.
*
* BRLTTY comes with ABSOLUTELY NO WARRANTY.
*
* This is free software, placed 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. Please see the file LICENSE-GPL for details.
*
* Web Page: http://mielke.cc/brltty/
*
* This software is maintained by Dave Mielke <dave@mielke.cc>.
*/
/*
* Miscellaneous FM chip soundcard routines for BRLTTY.
* Implemented by Dave Mielke <dave@mielke.cc>.
* Method gleaned from sccw, a morse code program written
* by Steven J. Merrifield <sjm@ee.latrobe.edu.au> (VK3ESM).
* Must compile with -O2.
* Must link with -lm.
* May compile with -DDEBUG_ADLIB.
*/
#include "prologue.h"
#include "log.h"
#include "timing.h"
#include "system.h"
#include "adlib.h"
const unsigned char AL_channelOffsets[] = {
/* 1 2 3 4 5 6 7 8 9 */
0X00, 0X01, 0X02, 0X08, 0X09, 0X0A, 0X10, 0X11, 0X12
};
const unsigned char AL_channelCount = ARRAY_COUNT(AL_channelOffsets);
static unsigned int portsEnabledCount = 0;
int
AL_enablePorts (int errorLevel) {
if (portsEnabledCount) return 1;
if (enablePorts(errorLevel, ALP_REGISTER, 1)) {
if (enablePorts(errorLevel, ALP_DATA, 1)) {
portsEnabledCount++;
return 1;
}
disablePorts(ALP_REGISTER, 1);
}
return 0;
}
void
AL_disablePorts (void) {
if (!--portsEnabledCount) {
disablePorts(ALP_REGISTER, 1);
disablePorts(ALP_DATA, 1);
}
}
unsigned char
AL_readStatus (void) {
return readPort1(ALP_STATUS);
}
static void
AL_writeDelay (int delay) {
while (delay-- > 0) {
AL_readStatus();
}
}
void
AL_writeRegister (int number, unsigned char data) {
/* LogPrint(LOG_DEBUG, "AL_writeRegister: %2.2X=%2.2X", number, data); */
writePort1(ALP_REGISTER, number);
AL_writeDelay(6);
writePort1(ALP_DATA, data);
AL_writeDelay(35);
}
void
AL_resetCard (void) {
int number;
for (number=ALR_FIRST; number<=ALR_LAST; ++number) {
AL_writeRegister(number, 0);
}
}
static void
AL_resetTimers (void) {
AL_writeRegister(ALR_TCTL, AL_TCTL_T1MASK|AL_TCTL_T2MASK);
AL_writeRegister(ALR_TCTL, AL_TCTL_RESET);
}
int
AL_testCard (int errorLevel) {
const unsigned char mask = AL_STAT_EXP | AL_STAT_EXP1 | AL_STAT_EXP2;
AL_resetTimers();
if (!(AL_readStatus() & mask)) {
unsigned char status;
AL_writeRegister(ALR_T1DATA, 0xFF);
AL_writeRegister(ALR_TCTL, AL_TCTL_T1START|AL_TCTL_T2MASK);
usleep(80);
status = AL_readStatus();
AL_resetTimers();
if ((status & mask) == (AL_STAT_EXP | AL_STAT_EXP1)) return 1;
}
LogPrint(errorLevel, "FM synthesizer initialization failure");
return 0;
}
void
AL_evaluatePitch (int pitch, int *exponent, int *mantissa) {
int shift = 21;
while ((*mantissa = (int)((float)pitch * (1 << --shift) / 50000.0)) > 0X3FF);
*exponent = 20 - shift;
}
void
AL_initiateTone (int channel, int exponent, int mantissa) {
/* LogPrint(LOG_DEBUG, "AL_initiateTone: %1.1X[%3.3X]", exponent, mantissa); */
AL_writeRegister(ALR_FREQUENCY_LSB(channel),
(mantissa & 0XFF));
AL_writeRegister(ALR_FREQUENCY_MSB(channel),
(((mantissa >> 8) & 0X3) |
((exponent & 0X7) << AL_OCTAVE_SHIFT) |
AL_FREQ_ON));
}
void
AL_startTone (int channel, int pitch) {
int exponent;
int mantissa;
AL_evaluatePitch(pitch, &exponent, &mantissa);
/* LogPrint(LOG_DEBUG, "AL_startTone: %d", pitch); */
AL_initiateTone(channel, exponent, mantissa);
}
void
AL_stopTone (int channel) {
AL_writeRegister(ALR_FREQUENCY_MSB(channel), 0);
}
void
AL_playTone (int channel, int pitch, unsigned long int duration, int volume) {
/* Play tone at fundamental frequency. */
AL_writeRegister(ALR_MODULATOR(ALG_EFFECT, channel),
(AL_HARMONIC_1 << AL_HARMONIC_SHIFT));
/* Set the carrier to the fundamental frequency. */
AL_writeRegister(ALR_CARRIER(ALG_EFFECT, channel),
(AL_HARMONIC_1 << AL_HARMONIC_SHIFT));
/* Set the volume (passed in as 0-100) */
AL_writeRegister(ALR_CARRIER(ALG_LEVEL, channel),
((AL_VOLUME_SOFT - ((AL_VOLUME_SOFT * volume) / 100)) << AL_VOLUME_SHIFT));
/* Set fast attack and slow decay. */
AL_writeRegister(ALR_CARRIER(ALG_ATTDEC, channel),
((AL_ATTACK_FAST << AL_ATTACK_SHIFT) |
(AL_DECAY_SLOW << AL_DECAY_SHIFT)));
/* Set soft sustain and fast release. */
AL_writeRegister(ALR_CARRIER(ALG_SUSREL, channel),
((AL_SUSTAIN_SOFT << AL_SUSTAIN_SHIFT) |
(AL_RELEASE_FAST << AL_RELEASE_SHIFT)));
AL_startTone(channel, pitch);
accurateDelay(duration);
AL_stopTone(channel);
}
|
