1 /*-
2  * spkr.c -- device driver for console speaker
46  * PPI controls whether sound is passed through at all; the PIT's channel 2 is
118  * M[LNS] are missing; the ~ synonym and the _ slur mark and the octave-
124 #define dtoi(c)		((c) - '0')
127 static int whole;	/* whole-note time at current tempo, in ticks */
129 static int fill;	/* controls spacing of notes */
130 static bool octtrack;	/* octave-tracking on? */
131 static bool octprefix;	/* override current octave-tracking state? */
139 #define DFLT_VALUE	4	/* default value (quarter-note) */
151 /* letter to half-tone:  A   B  C  D  E  F  G */
155  * This is the American Standard A440 Equal-Tempered scale with frequencies
191 	/* this weirdness avoids floating-point arithmetic */  in playtone()
192 	for (; sustain; sustain--) {  in playtone()
201 	if (pitch == -1)  in playtone()
205 			- (whole * (FILLTIME - fill)) / (value * FILLTIME);  in playtone()
206 		silence = whole * (FILLTIME-fill) * snum / (FILLTIME * value * sdenom);  in playtone()
228 				{v = v * 10 + (*++cp - '0'); slen--;}  in playstring()
229 	for (; slen--; cp++) {  in playstring()
246 			pitch = notetab[c - 'A'] + octave * OCTAVE_NOTES;  in playstring()
252 				slen--;  in playstring()
253 			} else if (cp[1] == '-') {  in playstring()
254 				--pitch;  in playstring()
256 				slen--;  in playstring()
260 			 * If octave-tracking mode is on, and there has been no octave-  in playstring()
265 				if (abs(pitch-lastpitch) > abs(pitch+OCTAVE_NOTES -   in playstring()
271 				if (abs(pitch-lastpitch) > abs((pitch-OCTAVE_NOTES) -   in playstring()
273 					--octave;  in playstring()
274 					pitch -= OCTAVE_NOTES;  in playstring()
287 				slen--;  in playstring()
296 				slen--;  in playstring()
308 				slen--;  in playstring()
312 				slen--;  in playstring()
321 			if (octave < nitems(pitchtab) / OCTAVE_NOTES - 1)  in playstring()
327 				octave--;  in playstring()
333 				slen--;  in playstring()
340 				slen--;  in playstring()
342 			playtone(pitch - 1, value, sustain);  in playstring()
357 				slen--;  in playstring()
360 			playtone(-1, timeval, sustain);  in playstring()
372 				slen--;  in playstring()
376 				slen--;  in playstring()
380 				slen--;  in playstring()
421 		devtoname(dev), uio->uio_resid);  in spkrwrite()
424 	if (uio->uio_resid > (DEV_BSIZE - 1))     /* prevent system crashes */  in spkrwrite()
431 		n = uio->uio_resid;  in spkrwrite()
468 		if (tp->frequency == 0)  in spkrioctl()
469 			rest(tp->duration);  in spkrioctl()
471 			tone(tp->frequency, tp->duration);  in spkrioctl()