1.\" 2.\" $Id: spkr.4,v 1.9 1997/03/21 20:13:56 mpp Exp $ 3.\" 4.Dd November 7, 1993 5.Dt SPKR 4 i386 6.Os FreeBSD 7.Sh NAME 8.Nm speaker , 9.Nm spkr 10.Nd console speaker device driver 11.Sh SYNOPSIS 12.Cd pseudo-device speaker 13.Fd #include <machine/speaker.h> 14.Sh DESCRIPTION 15The speaker device driver allows applications to control the PC console 16speaker on an 17.Tn IBM-PC Ns --compatible 18machine running 19.Tn FreeBSD . 20.Pp 21Only one process may have this device open at any given time; 22.Xr open 2 23and 24.Xr close 2 25are used to lock and relinquish it. An attempt to open when 26another process has the device locked will return -1 with an 27.Er EBUSY 28error 29indication. Writes to the device are interpreted as `play strings' in a 30simple ASCII melody notation. An 31.Xr ioctl 2 32request 33for tone generation at arbitrary 34frequencies is also supported. 35.Pp 36Sound-generation does not monopolize the processor; in fact, the driver 37spends most of its time sleeping while the PC hardware is emitting 38tones. Other processes may emit beeps while the driver is running. 39.Pp 40Applications may call 41.Xr ioctl 2 42on a speaker file descriptor to control the 43speaker driver directly; definitions for the 44.Xr ioctl 2 45interface are in 46.Pa /usr/include/machine/speaker.h . 47The 48.Li tone_t 49structure used in these calls has two fields, 50specifying a frequency (in Hz) and a duration (in 1/100ths of a second). 51A frequency of zero is interpreted as a rest. 52.Pp 53At present there are two such 54.Xr ioctl 2 55calls. 56.Dv SPKRTONE 57accepts a pointer to a 58single tone structure as third argument and plays it. 59.Dv SPKRTUNE 60accepts a 61pointer to the first of an array of tone structures and plays them in 62continuous sequence; this array must be terminated by a final member with 63a zero duration. 64.Pp 65The play-string language is modelled on the PLAY statement conventions of 66.Tn IBM 67Advanced BASIC 2.0. The 68.Li MB , 69.Li MF , 70and 71.Li X 72primitives of PLAY are not 73useful in a timesharing environment and are omitted. The `octave-tracking' 74feature and the slur mark are new. 75.Pp 76There are 84 accessible notes numbered 1-83 in 7 octaves, each running from 77C to B, numbered 0-6; the scale is equal-tempered A440 and octave 3 starts 78with middle C. By default, the play function emits half-second notes with the 79last 1/16th second being `rest time'. 80.Pp 81Play strings are interpreted left to right as a series of play command groups; 82letter case is ignored. Play command groups are as follows: 83.Bl -tag -width CDEFGABxx 84.It Li CDEFGAB 85Letters A through G cause the corresponding note to be played in the 86current octave. A note letter may optionally be followed by an 87.Dq Em "accidental sign" , 88one of # + or -; the first two of these cause it to be sharped one 89half-tone, the last causes it to be flatted one half-tone. It may 90also be followed by a time value number and by sustain dots (see 91below). Time values are interpreted as for the L command below. 92.It Ns Li O Sy n 93If 94.Sy n 95is numeric, this sets the current octave. 96.Sy n 97may also be one of 98.Li L 99or 100.Li N 101to enable or disable octave-tracking (it is disabled by default). 102When octave-tracking is on, interpretation of a pair of letter notes 103will change octaves if necessary in order to make the smallest 104possible jump between notes. Thus ``olbc'' will be played as 105``olb>c'', and ``olcb'' as ``olc<b''. Octave locking is disabled for 106one letter note following >, < and O[0123456]. (The octave-locking 107feature is not supported in 108.Tn IBM 109BASIC.) 110.It Li > 111Bump the current octave up one. 112.It Li < 113Drop the current octave down one. 114.It Ns Li N Sy n 115Play note 116.Sy n , 117.Sy n 118being 1 to 84 or 0 for a rest of current time value. 119May be followed by sustain dots. 120.It Ns Li L Sy n 121Sets the current time value for notes. The default is 122.Li L4 , 123quarter or crotchet notes. The lowest possible value is 1; values up 124to 64 are accepted. 125.Li L1 126sets whole notes, 127.Li L2 128sets half notes, 129.Li L4 130sets quarter notes, etc. 131.It Ns Li P Sy n 132Pause (rest), with 133.Sy n 134interpreted as for 135.Ns Li L Sy n . 136May be followed by 137sustain dots. May also be written 138.Li ~ . 139.It Ns Li T Sy n 140Sets the number of quarter notes per minute; default is 120. Musical 141names for common tempi are: 142 143.Bd -literal -offset indent 144 Tempo Beats Per Minute 145very slow Larghissimo 146 Largo 40-60 147 Larghetto 60-66 148 Grave 149 Lento 150 Adagio 66-76 151slow Adagietto 152 Andante 76-108 153medium Andantino 154 Moderato 108-120 155fast Allegretto 156 Allegro 120-168 157 Vivace 158 Veloce 159 Presto 168-208 160very fast Prestissimo 161.Ed 162.It Li M[LNS] 163Set articulation. 164.Li MN 165.Ns No ( Li N 166for normal) is the default; the last 1/8th of 167the note's value is rest time. You can set 168.Li ML 169for legato (no rest space) or 170.Li MS 171for staccato (1/4 rest space). 172.El 173.Pp 174Notes (that is, 175.Li CDEFGAB 176or 177.Li N 178command character groups) may be followed by 179sustain dots. Each dot causes the note's value to be lengthened by one-half 180for each one. Thus, a note dotted once is held for 3/2 of its undotted value; 181dotted twice, it is held 9/4, and three times would give 27/8. 182.Pp 183A note and its sustain dots may also be followed by a slur mark (underscore). 184This causes the normal micro-rest after the note to be filled in, slurring it 185to the next one. (The slur feature is not supported in 186.Tn IBM 187BASIC.) 188.Pp 189Whitespace in play strings is simply skipped and may be used to separate 190melody sections. 191.Sh BUGS 192Due to roundoff in the pitch tables and slop in the tone-generation and timer 193hardware (neither of which was designed for precision), neither pitch accuracy 194nor timings will be mathematically exact. There is no volume control. 195.Pp 196The action of two or more sustain dots does not reflect standard musical 197notation, in which each dot adds half the value of the previous dot 198modifier, not half the value of the note as modified. Thus, a note dotted 199once is held for 3/2 of its undotted value; dotted twice, it is held 7/4, 200and three times would give 15/8. The multiply-by-3/2 interpretation, 201however, is specified in the 202.Tn IBM 203BASIC manual and has been retained for 204compatibility. 205.Pp 206In play strings which are very long (longer than your system's physical I/O 207blocks) note suffixes or numbers may occasionally be parsed incorrectly due 208to crossing a block boundary. 209.Sh FILES 210.Bl -tag -width /dev/speakerxx 211.It Pa /dev/speaker 212speaker device file 213.El 214.Sh SEE ALSO 215.Xr spkrtest 8 216.Sh AUTHORS 217.An Eric S. Raymond Aq esr@snark.thyrsus.com 218June 1990 219.Sh "PORTED BY" 220.An Andrew A. Chernov Aq ache@astral.msk.su 221.Sh HISTORY 222The 223.Nm 224device appeared in 225.Fx 1.0 . 226