In freebsd-questions Digest, Vol 461, Issue 6, Message: 1 (sorry about the threading) On Wed, 3 Apr 2013 15:12:17 +0200 Polytropon <free...@edvax.de> wrote: > On Tue, 02 Apr 2013 19:10:59 -0700, Ronald F. Guilmette wrote: > > See how the entire ioctl() interface for these device types is completely > > documented IN THE MAN PAGE? That's the way it should be... None of this > > rooting around in the sources for something that should have been > > documented > > properly, external to the kernel sources. > > I agree that especially to developers, that sounds logical > and very helpful. Seems that manpages do not aim for that > goal anymore...
Well I can't help but feel this is being taken a tad more seriously than speaker(4) deserves - but it was first committed to FreeBSD 1.0 in '93, 19 years and 9 months ago in what is now SVN revision 4 (!), originally written by Eric Raymond in '90 then modified by ache(@) from "386bsd only clean version, all SYSV stuff removed", suggesting more ancient origins. So I'm not sure this doesn't rather predate 'anymore' :) One's referred to the source in /sys/dev/speaker/speaker.h (a few lines) and it's not a long jump to peek at /sys/dev/speaker/spkr.c http://svnweb.freebsd.org/base/head/sys/dev/speaker/spkr.c?annotate=4 This original one is easier to follow at the bare metal level, with direct inb() and outb() to the PIT (i8254) timer #2, functions later moved into clock.c, making one have to refer to all of 4 source files for the 'machine independent' modern version, though I wonder if anyone not on x86/pc98 is/was actually using spkr(4)? With r177648 5 years ago, phk@ said "If somebody cleaned this code up to proper style(9), it could become a great educational starting point for aspiring kernel hackers." 2 months later: "Move speaker a lot closer to style(9)". It was one of the first devices I could follow, at any rate. > > It doesn't have to cover "everything". But it _should_ completely describe > > the programatic interface. > > At least is leaves questions, like stating "use the syscalls > in order to...", and the reader is left with the most obvious > question: _which_ syscalls? Sometimes examples are the best teachers. spkrtest(8) is just a sh script that writes to the device. For more sophisticated use (!) spkr.c is overcommented, if anything, and it's only ~550 well-spaced lines. > > But like I said, somewher along the line, a lot of man page writers > > apparently got lazy... VERY lazy. Mmm, and a few man page readers too? It's really not rocket science .. > But keep in mind they're still alive! Judging from the manpages > of... *cough* can I say this? YOu know, more prominent open > source operating systems for desktops... they're usually much > worse _if_ there is a manpage. In most cases, there's none. True. And I can usually get little more sense out of info(1) than from windows 'troubleshooter' :) > > >> Second order question: Why can't I just pipe a .wav file to the > > >> /dev/speaker device file and have it play? Wouldn't that make quite > > >> a lot of sense? > > > > > >No, that does not work. > > > > Apparently not. > > > > Why it doesn't work (or couldn't work) is less clear. > > The speaker interface to the _PC speaker_ is not a DSP. It's > programming is much simpler. The "note language" that it > uses on FreeBSD is much more than other interfaces offer. > Better ones have stuff like pitch, duration, turn off. Not to mention staccato, legato, dotted notes - sophisticated stuff! [..] > > > % echo "c" > /dev/speaker > > > > Humm... now _that_ is both interesting and enlightening. > > I actually remember having used something comparable on > BASIC, when my brain wasn't fully developed yet. :-) The note language is _from_ BASIC .. do read the source, Luke(s)! > echo "cdefgab>c" > /dev/speaker > > It's still a nice interface to "generate attention sounds" > in case you want to make an audible alarm or signal for > some specific action, like a program which has aborted, > an unverified backup or the successful completition of > a task. Indeed it is. On an old laptop using APM I used to play little tunes as the battery got down to 30, 20, 10%, noiser just before forced suspend, which saved me not a few times. A nice little chirp when fully charged. [..] > > >> I wonder if whoever write and distributed this realized that he/she > > >> could > > >> be sued for copyright infringement for about 5 of the simple tunes that > > >> are > > >> embedded in that thing. Sad but true. > > >> :-( I hope noone's losing too much sleep, after ~20 uneventful years :) cheers, Ian _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
